Caveolin-associated filamentous actin (Cav-actin) defines a novel F-actin structure in adipocytes.
AuthorsKanzaki M, Pessin JE
JournalJ Biol Chem
PubMed ID12039946
Dynamic actin remodeling has been implicated in the translocation of the insulin-responsive glucose transporter 4 (GLUT4) to the plasma membrane in adipocytes. Here we show that fully differentiated 3T3L1 adipocytes have unique cortical filamentous actin structure, designated Cav-actin (caveolae-associated F-actin). During 3T3L1 adipocyte differentiation, rhodamine-phalloidin staining demonstrated the formation of ... More
Polarity establishment requires dynamic actin in fucoid zygotes.
AuthorsHable WE, Miller NR, Kropf DL
JournalProtoplasma
PubMed ID12802626
Previous work has demonstrated that actin plays important roles in axis establishment and polar growth in fucoid zygotes. Distinct actin arrays are associated with fertilization, polarization, growth, and division, and agents that depolymerize actin filaments (cytochalasins, latrunculin B) perturb these stages of the first cell cycle. Rearrangements of actin arrays ... More
The actin cytoskeleton is required for the trafficking of the B cell antigen receptor to the late endosomes.
AuthorsBrown BK, Song W
JournalTraffic
PubMed ID11389769
The B cell antigen receptor (BCR) plays two central roles in B cell activation: to internalize antigens for processing and presentation, and to initiate signal transduction cascades that both promote B cells to enter the cell cycle and facilitate antigen processing by accelerating antigen transport. An early event in B ... More
Involvement of integrins and Src in insulin signaling toward autophagic proteolysis in rat liver.
AuthorsSchliess F, Reissmann R, Reinehr R, vom Dahl S, Häussinger D
JournalJ Biol Chem
PubMed ID14985360
Cell volume changes critically determine hepatic signal transduction and metabolism. Hepatocyte swelling by insulin contributes to p38(MAPK) activation leading to inhibition of autophagic proteolysis. Recently integrins were shown to sense hypoosmotic hepatocyte swelling. Here the role of integrins, Src, and focal adhesion kinase (FAK) in insulin signaling was investigated using ... More
Actin Disruption by Latrunculin B Causes Turgor-Related Changes in Tip Growth of Saprolegnia ferax Hyphae
AuthorsGupta GD, Heath IB
JournalFungal Genet Biol
PubMed ID9073481
Hyphae of Saprolegnia ferax growing under normal or low-turgor conditions were exposed to 0.1-10 &mgr;g/ml latrunculin B, an actin inhibitor. In the first 10 s of addition, hyphae with normal turgor levels accelerated while those with low turgor decelerated, consistent with the suggestion that actin restrains or protrudes tips under ... More
Assembly of adherens junctions is required for sphingosine 1-phosphate-induced matriptase accumulation and activation at mammary epithelial cell-cell contacts.
AuthorsHung RJ, Hsu IaW, Dreiling JL, Lee MJ, Williams CA, Oberst MD, Dickson RB, Lin CY
JournalAm J Physiol Cell Physiol
PubMed ID15075215
Sphingosine 1-phosphate (S1P), a bioactive phospholipid, simultaneously induces actin cytoskeletal rearrangements and activation of matriptase, a membrane-associated serine protease in human mammary epithelial cells. In this study, we used a monoclonal antibody selective for activated, two-chain matriptase to examine the functional relationship between these two S1P-induced events. Ten minutes after ... More
PKC-induced intracellular trafficking of Ca(V)2 precedes its rapid recruitment to the plasma membrane.
AuthorsZhang Y, Helm JS, Senatore A, Spafford JD, Kaczmarek LK, Jonas EA,
JournalJ Neurosci
PubMed ID18322103
'Activation of protein kinase C (PKC) potentiates secretion in Aplysia peptidergic neurons, in part by inducing new sites for peptide release at growth cone terminals. The mechanisms by which ion channels are trafficked to such sites are, however, not well understood. We now show that PKC activation rapidly recruits new ... More
Modulation of acto-myosin contractility in skeletal muscle myoblasts uncouples growth arrest from differentiation.
AuthorsDhawan J, Helfman DM
JournalJ Cell Sci
PubMed ID15252113
'Cell-substratum interactions trigger key signaling pathways that modulate growth control and tissue-specific gene expression. We have previously shown that abolishing adhesive interactions by suspension culture results in G(0) arrest of myoblasts. We report that blocking intracellular transmission of adhesion-dependent signals in adherent cells mimics the absence of adhesive contacts. We ... More
Nerve growth factor signaling regulates motility and docking of axonal mitochondria.
AuthorsChada SR, Hollenbeck PJ
JournalCurr Biol
PubMed ID15268858
'Axonal transport is thought to distribute mitochondria to regions of the neuron where their functions are required. In cultured neurons, mitochondrial transport responds to growth cone activity, and this involves both a transition between motile and stationary states of mitochondria and modulation of their anterograde transport activity. Although the exact ... More
Actin- and protein-4.1-containing filaments link nuclear pore complexes to subnuclear organelles in Xenopus oocyte nuclei.
AuthorsKiseleva E, Drummond SP, Goldberg MW, Rutherford SA, Allen TD, Wilson KL
JournalJ Cell Sci
PubMed ID15128868
'We imaged the interiors of relatively intact Xenopus oocyte nuclei by field emission scanning electron microscopy (feSEM) and visualized a network of filaments that attach to nuclear pore complexes and extend throughout the nucleus. Within the nucleus, these ''pore-linked filaments'' (PLFs) were embedded into spherical structures 100 nm to approximately ... More
Aberrant actin cytoskeleton leads to accelerated proliferation of corneal epithelial cells in mice deficient for destrin (actin depolymerizing factor).
AuthorsIkeda S, Cunningham LA, Boggess D, Hawes N, Hobson CD, Sundberg JP, Naggert JK, Smith RS, Nishina PM
JournalHum Mol Genet
PubMed ID12700171
'Corneal disease is the most common cause of bilateral blindness in the world. Visual loss in this condition is often due to changes in morphology and function of the corneal epithelial surface. Corneal disease-1 (corn1) and corn1(2J) are spontaneous mouse mutants that develop irregular thickening of the corneal epithelium, similar ... More
Influence of actin cytoskeleton on intra-articular and interstitial fluid pressures in synovial joints.
AuthorsPoli A, Scott D, Bertin K, Miserocchi G, Mason RM, Levick JR
JournalMicrovasc Res
PubMed ID11678632
'Fibroblast microfilamentous actin (F-actin) influences interstitial fluid pressure via linkages to collagen in rat skin (Berg et al., 2001). The present aims were to determine whether the actin cytoskeleton of synovial endothelium, fibroblasts, and synoviocytes influences in vivo (i) fluid exchange between a joint cavity and synovial microcirculation and (ii) ... More
Disruption of the actin cytoskeleton up-regulates iNOS expression in vascular smooth muscle cells.
AuthorsHattori Y, Kasai K
JournalJ Cardiovasc Pharmacol
PubMed ID14716207
'Cytokines and bacterial lipopolysaccharide (LPS) induce the expression of inducible nitric oxide synthase (iNOS), resulting in the release of nitric oxide (NO) from vascular smooth muscle cells. We here demonstrated that disruption of F-actin formation by sequestration of G-actin with the toxin latrunculin B (Lat B) dramatically potentiated LPS-induced iNOS ... More
Regulated exocytosis in neuroendocrine cells: a role for subplasmalemmal Cdc42/N-WASP-induced actin filaments.
AuthorsGasman S, Chasserot-Golaz S, Malacombe M, Way M, Bader MF
JournalMol Biol Cell
PubMed ID14617808
'In neuroendocrine cells, actin reorganization is a prerequisite for regulated exocytosis. Small GTPases, Rho proteins, represent potential candidates coupling actin dynamics to membrane trafficking events. We previously reported that Cdc42 plays an active role in regulated exocytosis in chromaffin cells. The aim of the present work was to dissect the ... More
The recruitment of the interleukin-1 (IL-1) receptor-associated kinase (IRAK) into focal adhesion complexes is required for IL-1beta -induced ERK activation.
AuthorsMacGillivray MK, Cruz TF, McCulloch CA
JournalJ Biol Chem
PubMed ID10823834
'The interleukin-1 (IL-1) receptor colocalizes with focal adhesion complexes (FACs), actin-enriched structures involved in cell adhesion and signaling in fibroblasts and chondrocytes. The colocalization of FACs and IL-1 receptors has been implicated in the restriction of IL-1 signaling transduction to ERK; however, the mechanism of this restriction and the requirement ... More
Disruption of the actin cytoskeleton abolishes high affinity 3H-glibenclamide binding in rat aortic rings.
AuthorsLöffler-Walz C, Quast U
JournalNaunyn Schmiedebergs Arch Pharmacol
PubMed ID9521492
'The interaction between the cytoskeleton and the ATP-sensitive K+ channel (KATP channel) was studied in rat aortic rings by examining the binding of the sulphonylurea blocker, 3H-glibenclamide, and of the opener, 3H-P1075. The actin cytoskeleton disrupting agents, cytochalasin D (1 microM) and latrunculin B (1 microM), abolished the high affinity ... More
Extracellular matrix proteins modulate endocytosis of the insulin receptor.
AuthorsBoura-Halfon S, Voliovitch H, Feinstein R, Paz K, Zick Y
JournalJ Biol Chem
PubMed ID12594209
'Internalization of the insulin receptor (IR) is a highly regulated multi-step process whose underlying molecular basis is not fully understood. Here we undertook to study the role of extracellular matrix (ECM) proteins in the modulation of IR internalization. Employing Chinese hamster ovary cells that overexpress IR (CHO-T cells), our results ... More
Actin cytoskeleton is required for nuclear accumulation of Gln3 in response to nitrogen limitation but not rapamycin treatment in Saccharomyces cerevisiae.
AuthorsCox KH, Tate JJ, Cooper TG
JournalJ Biol Chem
PubMed ID14970238
'Saccharomyces cerevisiae selectively utilizes good nitrogen sources in preference to poor ones by down-regulating transcription of genes encoding proteins that transport and degrade poor nitrogen sources when excess nitrogen is available. This regulation is designated nitrogen catabolite repression (NCR). When cells are transferred from a good to a poor nitrogen ... More
Identification of a novel sequence in PDZ-RhoGEF that mediates interaction with the actin cytoskeleton.
AuthorsBanerjee J, Wedegaertner PB
JournalMol Biol Cell
PubMed ID14742719
'Small GTPases of the Rho family are crucial regulators of actin cytoskeleton rearrangements. Rho is activated by members of the Rho guanine-nucleotide exchange factor (GEF) family; however, mechanisms that regulate RhoGEFs are not well understood. This report demonstrates that PDZ-RhoGEF, a member of a subfamily of RhoGEFs that contain regulator ... More
Synthesis of proto-oncogene proteins and cyclins depends on intact microfilaments.
AuthorsFasshauer M, Iwig M, Glaesser D
JournalEur J Cell Biol
PubMed ID9860134
'It is well established that microfilament disintegration by cytochalasin D (CD) as well as latrunculin (LAT)-A and LAT-B causes an inhibition of S phase entry of various nontransformed cell lines. Our experiments extended these observations to human embryonal diploid fibroblasts (Wi-38). To investigate the question whether this stop of DNA ... More
Mitochondrial calcium sequestration and protein kinase C cooperate in the regulation of cortical F-actin disassembly and secretion in bovine chromaffin cells.
AuthorsCuchillo-Ibáñez I, Lejen T, Albillos A, Rosé SD, Olivares R, Villarroya M, García AG, Trifaró JM
JournalJ Physiol
PubMed ID15133064
'Mitochondria play an important role in the homeostasis of intracellular Ca(2+) and regulate its availability for exocytosis. Inhibitors of mitochondria Ca(2+) uptake such as protonophore CCCP potentiate the secretory response to a depolarizing pulse of K(+). Exposure of cells to agents that directly (cytochalasin D, latrunculin B) or indirectly (PMA) ... More
Actin-dependent fluid-phase endocytosis in inner cortex cells of maize root apices.
AuthorsBaluska F, Samaj J, Hlavacka A, Kendrick-Jones J, Volkmann D
JournalJ Exp Bot
PubMed ID14739268
'The fluorescent dye Lucifer Yellow (LY) is a well-known and widely-used marker for fluid-phase endocytosis. In this paper, both light and electron microscopy revealed that LY was internalized into transition zone cells of the inner cortex of intact maize root apices. The internalized LY was localized within tubulo-vesicular compartments invaginating ... More
Unconventional myosin Myo1c promotes membrane fusion in a regulated exocytic pathway.
AuthorsBose A, Robida S, Furcinitti PS, Chawla A, Fogarty K, Corvera S, Czech MP
JournalMol Cell Biol
PubMed ID15169906
'Glucose homeostasis is controlled in part by regulation of glucose uptake into muscle and adipose tissue. Intracellular membrane vesicles containing the GLUT4 glucose transporter move towards the cell cortex in response to insulin and then fuse with the plasma membrane. Here we show that the fusion step is retarded by ... More
EFA6, exchange factor for ARF6, regulates the actin cytoskeleton and associated tight junction in response to E-cadherin engagement.
AuthorsLuton F, Klein S, Chauvin JP, Le Bivic A, Bourgoin S, Franco M, Chardin P
JournalMol Biol Cell
PubMed ID14668475
'We addressed the role of EFA6, exchange factor for ARF6, during the development of epithelial cell polarity in Madin-Darby canine kidney cells. EFA6 is located primarily at the apical pole of polarized cells, including the plasma membrane. After calcium-triggered E-cadherin-mediated cell adhesion, EFA6 is recruited to a Triton X-100-insoluble fraction ... More
Hyperosmolarity enhances the lung capillary barrier.
'Although capillary barrier deterioration underlies major inflammatory lung pathology, barrier-enhancing strategies are not available. To consider hyperosmolar therapy as a possible strategy, we gave 15-minute infusions of hyperosmolar sucrose in lung venular capillaries imaged in real time. Surprisingly, this treatment enhanced the capillary barrier, as indicated by quantification of the ... More
Spike-associated fast contraction of dendritic spines in cultured hippocampal neurons.
AuthorsKorkotian E, Segal M
JournalNeuron
PubMed ID11430808
'Dendritic spines have long been known to contain contractile elements and have recently been shown to express apparent spontaneous motility. Using high-resolution imaging of dendritic spines of green-fluorescent protein (GFP)-expressing, patch-clamped hippocampal neurons in dissociated culture, we find that bursts of action potentials, evoked by depolarizing current pulses, cause momentary ... More
Glucose-stimulated insulin secretion is coupled to the interaction of actin with the t-SNARE (target membrane soluble N-ethylmaleimide-sensitive factor attachment protein receptor protein) complex.
AuthorsThurmond DC, Gonelle-Gispert C, Furukawa M, Halban PA, Pessin JE
JournalMol Endocrinol
PubMed ID12554769
'The actin monomer sequestering agent latrunculin B depolymerized beta-cell cortical actin, which resulted in increased glucose-stimulated insulin secretion in both cultured MIN6 beta-cells and isolated rat islet cells. In perifused islets, latrunculin B treatment increased both first- and second-phase glucose-stimulated insulin secretion without any significant effect on total insulin content. ... More
Microtubules and microfilaments coordinate to direct a fountain streaming pattern in elongating conifer pollen tube tips.
'This study investigates how microtubules and microfilaments control organelle motility within the tips of conifer pollen tubes. Organelles in the 30-microm-long clear zone at the tip of Picea abies (L.) Karst. (Pinaceae) pollen tubes move in a fountain pattern. Within the center of the tube, organelles move into the tip ... More
Cytochalasin D and latrunculin affect chromosome behaviour during meiosis in crane-fly spermatocytes.
AuthorsForer A, Pickett-Heaps JD
JournalChromosome Res
PubMed ID9886773
'Living crane-fly spermatocytes were treated with 10-20 microg/ml cytochalasin D (CD) or 0.3 microg/ml latrunculin (LAT) at various stages of meiosis I. The drugs had the same effects on chromosome behaviour, but CD effects were reversible and LAT effects generally were not. When applied in mid-prometaphase to metaphase, both drugs ... More
Regulation of intercellular adhesion strength in fibroblasts.
AuthorsChan MW, El Sayegh TY, Arora PD, Laschinger CA, Overall CM, Morrison C, McCulloch CA
JournalJ Biol Chem
PubMed ID15247242
'The regulation of adherens junction formation in cells of mesenchymal lineage is of critical importance in tumorigenesis but is poorly characterized. As actin filaments are crucial components of adherens junction assembly, we studied the role of gelsolin, a calcium-dependent, actin severing protein, in the formation of N-cadherin-mediated intercellular adhesions. With ... More
Role of microtubules and tea1p in establishment and maintenance of fission yeast cell polarity.
AuthorsSawin KE, Snaith HA
JournalJ Cell Sci
PubMed ID14734657
'Microtubules and the protein tea1p have important roles in regulating cell polarity in the fission yeast Schizosaccharomyces pombe. Here, using combinations of drugs, environmental perturbations and genetic mutants, we demonstrate that once a cell polarity axis is established, microtubules have at best a minor role in maintaining the cortical actin ... More
Radial F-actin arrays precede new hypha formation in Saprolegnia: implications for establishing polar growth and regulating tip morphogenesis.
AuthorsBachewich C, Heath IB
JournalJ Cell Sci
PubMed ID9645948
'The roles of cortical F-actin in initiating and regulating polarized cell expansion in the form of hyphal tip morphogenesis were investigated by analyzing long term effects of F-actin disruption by latrunculin B in the oomycete Saprolegnia ferax, and detecting localized changes in the cortical F-actin organization preceding hyphal formation. Tubular ... More
Endocytic adaptor molecules reveal an endosomal population of clathrin by total internal reflection fluorescence microscopy.
AuthorsKeyel PA, Watkins SC, Traub LM
JournalJ Biol Chem
PubMed ID14722064
'Most eukaryotes utilize a single pool of clathrin to assemble clathrin-coated transport vesicles at different intracellular locations. Coat assembly is a cyclical process. Soluble clathrin triskelia are recruited to the membrane surface by compartment-specific adaptor and/or accessory proteins. Adjacent triskelia then pack together to assemble a polyhedral lattice that progressively ... More
Bulk membrane retrieval in the synaptic terminal of retinal bipolar cells.
AuthorsHolt M, Cooke A, Wu MM, Lagnado L
JournalJ Neurosci
PubMed ID12598621
'The mechanism of bulk membrane uptake at the synapse remains poorly defined, although exocytosis of synaptic vesicles is followed by compensatory membrane retrieval into both small vesicles and large cisternas or vacuoles. We investigated bulk retrieval in the presynaptic terminal of retinal bipolar cells. Fluorescence imaging of the membrane dye ... More
The actin cytoskeleton facilitates complement-mediated activation of cytosolic phospholipase A2.
AuthorsCybulsky AV, Takano T, Papillon J, Khadir A, Bijian K, Le Berre L
JournalAm J Physiol Renal Physiol
PubMed ID14644750
'Cytosolic PLA(2)-alpha (cPLA(2)) and metabolites of arachidonic acid (AA) are key mediators of complement-dependent glomerular epithelial cell (GEC) injury. Assembly of C5b-9 increases cytosolic Ca(2+) concentration and results in transactivation of receptor tyrosine kinases and activation of PLC-gamma 1 and the 1,2-diacylglycerol (DAG)-PKC pathway. Ca(2+) and PKC are essential for ... More
The subapical compartment: a traffic center in membrane polarity development.
AuthorsHoekstra D, Tyteca D, van IJzendoorn SC
JournalJ Cell Sci
PubMed ID15126620
'Spatially separated apical and basolateral plasma membrane domains that have distinct functions and molecular compositions are a characteristic feature of epithelial cell polarity. The subapical compartment (SAC), also known as the common endosome (CE), where endocytic pathways from both surfaces merge, plays a crucial role in the maintenance and probably ... More
Enhanced gravitropism of roots with a disrupted cap actin cytoskeleton.
AuthorsHou G, Mohamalawari DR, Blancaflor EB
JournalPlant Physiol
PubMed ID12644685
'The actin cytoskeleton has been proposed to be a major player in plant gravitropism. However, understanding the role of actin in this process is far from complete. To address this problem, we conducted an analysis of the effect of Latrunculin B (Lat B), a potent actin-disrupting drug, on root gravitropism ... More
Use of abnormal preprophase bands to decipher division plane determination.
AuthorsGranger C, Cyr R
JournalJ Cell Sci
PubMed ID11171328
'Many premitotic plant cells possess a cortical preprophase band of microtubules and actin filaments that encircles the nucleus. In vacuolated cells, the preprophase band is visibly connected to the nucleus by a cytoplasmic raft of actin filaments and microtubules termed the phragmosome. Typically, the location of the preprophase band and ... More
Mechanism of actin polymerization in cellular ATP depletion.
AuthorsAtkinson SJ, Hosford MA, Molitoris BA
JournalJ Biol Chem
PubMed ID14623892
'Cellular ATP depletion in diverse cell types results in the net conversion of monomeric G-actin to polymeric F-actin and is an important aspect of cellular injury in tissue ischemia. We propose that this conversion results from altering the ratio of ATP-G-actin and ADP-G-actin, causing a net decrease in the concentration ... More
Stretch of the vascular wall induces smooth muscle differentiation by promoting actin polymerization.
AuthorsAlbinsson S, Nordström I, Hellstrand P
JournalJ Biol Chem
PubMed ID15184395
'Stretch of the vascular wall by the intraluminal blood pressure stimulates protein synthesis and contributes to the maintenance of the smooth muscle contractile phenotype. The expression of most smooth muscle specific genes has been shown to be regulated by serum response factor and stimulated by increased actin polymerization. Hence we ... More
Lis1 and doublecortin function with dynein to mediate coupling of the nucleus to the centrosome in neuronal migration.
'Humans with mutations in either DCX or LIS1 display nearly identical neuronal migration defects, known as lissencephaly. To define subcellular mechanisms, we have combined in vitro neuronal migration assays with retroviral transduction. Overexpression of wild-type Dcx or Lis1, but not patient-related mutant versions, increased migration rates. Dcx overexpression rescued the ... More
Plant mitochondria move on F-actin, but their positioning in the cortical cytoplasm depends on both F-actin and microtubules.
AuthorsVan Gestel K, Köhler RH, Verbelen JP
JournalJ Exp Bot
PubMed ID11886885
'Mitochondrion movement and positioning was studied in elongating cultured cells of tobacco (Nicotiana tabacum L.), containing mitochondria-localized green fluorescent protein. In these cells mitochondria are either actively moving in strands of cytoplasm transversing or bordering the vacuole, or immobile positioned in the cortical layer of cytoplasm. Depletion of the cell''s ... More
Disruption of microtubules inhibits cytoplasmic ribonucleoprotein stress granule formation.
AuthorsIvanov PA, Chudinova EM, Nadezhdina ES
JournalExp Cell Res
PubMed ID14567982
'Stress granules are RNP-containing particles arising in the cytoplasm in response to environmental stress. They are dynamic structures assembling and disassembling in the cytoplasm very rapidly. We have studied whether the cytoskeleton is involved in the formation of stress granules. Stress granules were induced in CV-1 cells by sodium arsenate ... More
The behaviour of the plasma membrane during plasmolysis: a study by UV microscopy.
AuthorsLang-Pauluzzi I
JournalJ Microsc
PubMed ID10849197
'A high resolution ultraviolet (UV) bright-field microscope was used to analyse the formation of Hechtian strands and the Hechtian reticulation that remain attached to the cell wall after plasmolysis and deplasmolysis of onion inner epidermal cells. In real time video images, UV microscopy allowed a detailed investigation of the dynamic ... More
The PXL1 gene of Saccharomyces cerevisiae encodes a paxillin-like protein functioning in polarized cell growth.
AuthorsMackin NA, Sousou TJ, Erdman SE
JournalMol Biol Cell
PubMed ID14767053
'The Saccharomyces cerevisiae open reading frame YKR090w encodes a predicted protein displaying similarity in organization to paxillin, a scaffolding protein that organizes signaling and actin cytoskeletal regulating activities in many higher eucaryotic cell types. We found that YKR090w functions in a manner analogous to paxillin as a mediator of polarized ... More
Role of the cytoskeleton in mediating cAMP-dependent protein kinase inhibition of the epithelial Na+/H+ exchanger NHE3.
'The Na(+)/H(+) exchanger NHE3 isoform mediates the entry of Na(+) into epithelial cells of the kidney and gastrointestinal tract. Hormones and pharmacological agents that activate cAMP-dependent protein kinase A (PKA) are potent inhibitors of native and ectopically expressed NHE3 in epithelial and Chinese hamster ovary AP-1 cells, respectively. Previous studies ... More
F-actin does not modulate the initial steps of the protein kinase C activation process in living nerve cells.
AuthorsGeeraert V, Dupont JL, Grant NJ, Huvet C, Chasserot-Golaz S, Janoshazi A, Procksch O, de Barry J
JournalExp Cell Res
PubMed ID14499623
'Actin is a major substrate for protein kinase C (PKC) and PKC is considered a modulator of the actin network. In addition in vitro studies (Biochemistry 39 (2000) 271) have suggested that all PKC isoforms bind to actin during the process of activation of the enzyme. To test the physiological ... More
A novel form of actin in Leishmania: molecular characterisation, subcellular localisation and association with subpellicular microtubules.
AuthorsSahasrabuddhe AA, Bajpai VK, Gupta CM
JournalMol Biochem Parasitol
PubMed ID14747148
'To study the occurrence and subcellular distribution of actin in trypanosomatid parasites, we have cloned and overexpressed Leishmania donovani actin gene in bacteria, purified the protein, and employed the affinity purified rabbit polyclonal anti-recombinant actin antibodies as a probe to study the organisation and subcellular distribution of actin in Leishmania ... More
Cytoskeletal rearrangement and signal transduction in TGF-beta1-stimulated mesangial cell collagen accumulation.
AuthorsHubchak SC, Runyan CE, Kreisberg JI, Schnaper HW
JournalJ Am Soc Nephrol
PubMed ID12874450
'TGF-beta1 has been implicated in glomerular extracellular matrix accumulation, although the precise cellular mechanism(s) by which this occurs is not fully understood. The authors have previously shown that the Smad signaling pathway is present and functional in human glomerular mesangial cells and plays a role in activating type I collagen ... More
Cytoskeletal proteins are coordinately increased in maize genotypes with high levels of eEF1A.
AuthorsLopez-Valenzuela JA, Gibbon BC, Holding DR, Larkins BA
JournalPlant Physiol
PubMed ID15247373
'The opaque2 (o2) mutation increases the Lys content of maize (Zea mays) endosperm by reducing the synthesis of zein storage proteins and increasing the accumulation of other types of cellular proteins. Elongation factor 1A (eEF1A) is one of these proteins, and its concentration is highly correlated with the amount of ... More
Latrunculin B-induced plant dwarfism: Plant cell elongation is F-actin-dependent.
AuthorsBaluska F, Jasik J, Edelmann HG, Salajová T, Volkmann D
JournalDev Biol
PubMed ID11180956
'Marine macrolides latrunculins are highly specific toxins which effectively depolymerize actin filaments (generally F-actin) in all eukaryotic cells. We show that latrunculin B is effective on diverse cell types in higher plants and describe the use of this drug in probing F-actin-dependent growth and in plant development-related processes. In contrast ... More
Insulin-induced actin filament remodeling colocalizes actin with phosphatidylinositol 3-kinase and GLUT4 in L6 myotubes.
AuthorsKhayat ZA, Tong P, Yaworsky K, Bloch RJ, Klip A
JournalJ Cell Sci
PubMed ID10633079
'We examined the temporal reorganization of actin microfilaments by insulin and its participation in the localization of signaling molecules and glucose transporters in L6 myotubes expressing myc-tagged glucose transporter 4 (GLUT4myc). Scanning electron microscopy revealed a dynamic distortion of the dorsal cell surface (membrane ruffles) upon insulin treatment. In unstimulated ... More
Visualization of antigen presentation by actin-mediated targeting of glycolipid-enriched membrane domains to the immune synapse of B cell APCs.
AuthorsGordy C, Mishra S, Rodgers W
JournalJ Immunol
PubMed ID14764667
'Glycolipid-enriched membrane (GEM) domains, or lipid rafts, function in signaling in immune cells, but their properties during Ag presentation are less clear. To address this question, GEM domains were studied using fluorescence cell imaging of mouse CH27 B cells presenting Ag to D10 T cells. Our experiments showed that APCs ... More
Actin and microtubule regulation of trans-Golgi network architecture, and copper-dependent protein transport to the cell surface.
AuthorsCobbold C, Coventry J, Ponnambalam S, Monaco AP
JournalMol Membr Biol
PubMed ID14668139
'The Menkes disease ATPase (MNK) is a copper transporter that localizes to the mammalian trans-Golgi network (TGN) and shows substantial co-localization wih a ubiquitous TGN resident protein and marker, TGN46. We tested our hypothesis that these two TGN residents and integral membrane proteins are localized to biochemically distinct TGN sub-compartments ... More
Actin dependence of polarized receptor recycling in Madin-Darby canine kidney cell endosomes.
AuthorsSheff DR, Kroschewski R, Mellman I
JournalMol Biol Cell
PubMed ID11809838
'Mammalian epithelial cell plasma membrane domains are separated by junctional complexes supported by actin. The extent to which actin acts elsewhere to maintain cell polarity remains poorly understood. Using latrunculin B (Lat B) to depolymerize actin filaments, several basolateral plasma membrane proteins were found to lose their polarized distribution. This ... More
CRM1-dependent, but not ARE-mediated, nuclear export of IFN-alpha1 mRNA.
AuthorsKimura T, Hashimoto I, Nagase T, Fujisawa J
JournalJ Cell Sci
PubMed ID15126627
'While the bulk of cellular mRNA is known to be exported by the TAP pathway, export of specific subsets of cellular mRNAs may rely on chromosome region maintenance 1 (CRM1). One line of evidence supporting this hypothesis comes from the study of mRNAs of certain early response genes (ERGs) containing ... More
Antagonism between Ena/VASP Proteins and Actin Filament Capping Regulates Fibroblast Motility.
Authors Bear James E; Svitkina Tatyana M; Krause Matthias; Schafer Dorothy A; Loureiro Joseph J; Strasser Geraldine A; Maly Ivan V; Chaga Oleg Y; Cooper John A; Borisy Gary G; Gertler Frank B;
JournalCell
PubMed ID12086607
'Cell motility requires lamellipodial protrusion, a process driven by actin polymerization. Ena/VASP proteins accumulate in protruding lamellipodia and promote the rapid actin-driven motility of the pathogen Listeria. In contrast, Ena/VASP negatively regulate cell translocation. To resolve this paradox, we analyzed the function of Ena/VASP during lamellipodial protrusion. Ena/VASP-deficient lamellipodia protruded ... More
cdc42 regulates the exit of apical and basolateral proteins from the trans-Golgi network.
AuthorsMüsch A, Cohen D, Kreitzer G, Rodriguez-Boulan E
JournalEMBO J
PubMed ID11331583
'It is well established that Rho-GTPases regulate vesicle fusion and fission events at the plasma membrane through their modulatory role on the cortical actin cytoskeleton. In contrast, their effects on intracellular transport processes and actin pools are less clear. It was recently shown that cdc42 associates with the Golgi apparatus ... More
Megakaryoblastic leukemia factor-1 transduces cytoskeletal signals and induces smooth muscle cell differentiation from undifferentiated embryonic stem cells.
AuthorsDu KL, Chen M, Li J, Lepore JJ, Mericko P, Parmacek MS,
JournalJ Biol Chem
PubMed ID14970199
'The SAP domain transcription factor myocardin plays a critical role in the transcriptional program regulating smooth muscle cell differentiation. In this report, we describe the capacity of myocardin to physically associate with megakaryoblastic leukemia factor-1 (MKL1) and characterize the function of MKL1 in smooth muscle cells (SMCs). The MKL1 gene ... More
Effects of the marine macrolides swinholide A and jasplakinolide on outflow facility in monkeys.
AuthorsTian B, Kiland JA, Kaufman PL
JournalInvest Ophthalmol Vis Sci
PubMed ID11726621
'PURPOSE: To determine effects of the marine macrolides swinholide A (Swin A) and jasplakinolide (Jas), alone or in conjunction with latrunculin B (Lat B) on outflow facility in monkeys. METHODS: Total outflow facility was measured by two-level constant-pressure perfusion of the anterior chamber before and after exchange with Swin A, ... More
F-actin-dependent insolubility of chromatin-modifying components.
AuthorsAndrin C, Hendzel MJ
JournalJ Biol Chem
PubMed ID15082715
'Many complexes involved in chromatin modification are difficult to isolate and commonly found associated with nuclear matrix preparations. In this study, we examine the elution properties of chromatin-modifying components under different extraction conditions. We find that most, but not all, histone acetyltransferases and histone deacetylases predominantly partition with the nuclear ... More
Rab27A and its effector MyRIP link secretory granules to F-actin and control their motion towards release sites.
AuthorsDesnos C, Schonn JS, Huet S, Tran VS, El-Amraoui A, Raposo G, Fanget I, Chapuis C, Ménasché G, de Saint Basile G, Petit C, Cribier S, Henry JP, Darchen F
JournalJ Cell Biol
PubMed ID14610058
'The GTPase Rab27A interacts with myosin-VIIa and myosin-Va via MyRIP or melanophilin and mediates melanosome binding to actin. Here we show that Rab27A and MyRIP are associated with secretory granules (SGs) in adrenal chromaffin cells and PC12 cells. Overexpression of Rab27A, GTPase-deficient Rab27A-Q78L, or MyRIP reduced secretory responses of PC12 ... More
Control of actin dynamics by p38 MAP kinase - Hsp27 distribution in the lamellipodium of smooth muscle cells.
AuthorsPichon S, Bryckaert M, Berrou E
JournalJ Cell Sci
PubMed ID15128872
'We investigated the role of the p38 mitogen-activated protein kinase (p38 MAPK) in the PDGF-BB-induced cytoskeleton remodeling that occurs during the migration of porcine aortic smooth muscle cells (SMC). We showed that p38 MAPK controlled the polymerization of actin that is required for PDGF-induced lamellipodia formation and migration. To investigate ... More
Hierarchy of protein assembly at the vertex ring domain for yeast vacuole docking and fusion.
AuthorsWang L, Merz AJ, Collins KM, Wickner W
JournalJ Cell Biol
PubMed ID12566429
'Vacuole tethering, docking, and fusion proteins assemble into a "vertex ring" around the apposed membranes of tethered vacuoles before catalyzing fusion. Inhibitors of the fusion reaction selectively interrupt protein assembly into the vertex ring, establishing a causal assembly hierarchy: (a) The Rab GTPase Ypt7p mediates vacuole tethering and forms the ... More
Cytoskeletal reorganization dependence of signaling by the gonadotropin-releasing hormone receptor.
AuthorsDavidson L, Pawson AJ, Millar RP, Maudsley S
JournalJ Biol Chem
PubMed ID14559894
'Activation of classical G protein-coupled receptors (GPCRs) like the mammalian gonadotropin-releasing hormone receptor (GnRHR) typically stimulates heterotrimeric G protein molecules that subsequently activate downstream effectors. Receptor activation of heterotrimeric G protein pathways primarily controls intermediary cell metabolism by elevation or diminution of soluble cytoplasmic second messenger molecules. We have demonstrated ... More
Fast Ca(2+)-dependent inactivation of the store-operated Ca2+ current (ISOC) in liver cells: a role for calmodulin.
AuthorsLitjens T, Harland ML, Roberts ML, Barritt GJ, Rychkov GY
JournalJ Physiol
PubMed ID15226409
'Store-operated Ca2+ channels (SOCs) provide a major pathway for Ca2+ entry in non-excitable cells. SOCs in immortalized liver cells are highly selective for Ca2+ over other cations and are similar to well-studied Ca2+ release activated Ca2+ (CRAC) channels in haematopoietic cell lines. In the present work, employing H4IIE liver cells, ... More
Modulation of the expression of connective tissue growth factor by alterations of the cytoskeleton.
AuthorsOtt C, Iwanciw D, Graness A, Giehl K, Goppelt-Struebe M
JournalJ Biol Chem
PubMed ID12951326
'Modulation of the cytoskeletal architecture was shown to regulate the expression of CTGF (connective tissue growth factor, CCN2). The microtubule disrupting agents nocodazole and colchicine strongly up-regulated CTGF expression, which was prevented upon stabilization of the microtubules by paclitaxel. As a consequence of microtubule disruption, RhoA was activated and the ... More
Angiotensin II stimulates NHE3 activity by exocytic insertion of the transporter: role of PI 3-kinase.
Authorsdu Cheyron D, Chalumeau C, Defontaine N, Klein C, Kellermann O, Paillard M, Poggioli J
JournalKidney Int
PubMed ID12911544
'BACKGROUND: Low-concentration angiotensin II (Ang II) stimulates Na+/H+ exchanger 3 (NHE3) activity in renal proximal tubule mainly via angiotensin II type 1 (AT1) receptors. The mechanisms that mediate the increase in NHE3 activity elicited by Ang II remain incompletely settled. METHODS: To assess a potential role of NHE3 trafficking in ... More
Cytomechanical properties of papaver pollen tubes are altered after self-incompatibility challenge.
AuthorsGeitmann A, McConnaughey W, Lang-Pauluzzi I, Franklin-Tong VE, Emons AM
JournalBiophys J
PubMed ID15111444
'Self-incompatibility (SI) in Papaver rhoeas triggers a ligand-mediated signal transduction cascade, resulting in the inhibition of incompatible pollen tube growth. Using a cytomechanical approach we have demonstrated that dramatic changes to the mechanical properties of incompatible pollen tubes are stimulated by SI induction. Microindentation revealed that SI resulted in a ... More
Infection and invasion of roots by symbiotic, nitrogen-fixing rhizobia during nodulation of temperate legumes.
AuthorsGage DJ
JournalMicrobiol Mol Biol Rev
PubMed ID15187185
'Bacteria belonging to the genera Rhizobium, Mesorhizobium, Sinorhizobium, Bradyrhizobium, and Azorhizobium (collectively referred to as rhizobia) grow in the soil as free-living organisms but can also live as nitrogen-fixing symbionts inside root nodule cells of legume plants. The interactions between several rhizobial species and their host plants have become models ... More
Regulated membrane trafficking of the insulin-responsive glucose transporter 4 in adipocytes.
AuthorsWatson RT, Kanzaki M, Pessin JE
JournalEndocr Rev
PubMed ID15082519
'Since the discovery of insulin roughly 80 yr ago, much has been learned about how target cells receive, interpret, and respond to this peptide hormone. For example, we now know that insulin activates the tyrosine kinase activity of its cell surface receptor, thereby triggering intracellular signaling cascades that regulate many ... More
Epidermolysis bullosa simplex-type mutations alter the dynamics of the keratin cytoskeleton and reveal a contribution of actin to the transport of keratin subunits.
AuthorsWerner NS, Windoffer R, Strnad P, Grund C, Leube RE, Magin TM
JournalMol Biol Cell
PubMed ID14668478
'Dominant keratin mutations cause epidermolysis bullosa simplex by transforming keratin (K) filaments into aggregates. As a first step toward understanding the properties of mutant keratins in vivo, we stably transfected epithelial cells with an enhanced yellow fluorescent protein-tagged K14R125C mutant. K14R125C became localized as aggregates in the cell periphery and ... More
Latrunculin B or ATP depletion induces cofilin-dependent translocation of actin into nuclei of mast cells.
AuthorsPendleton A, Pope B, Weeds A, Koffer A
JournalJ Biol Chem
PubMed ID12566455
'Increasing cellular G-actin, using latrunculin B, in either intact or permeabilized rat peritoneal mast cells, caused translocation of both actin and an actin regulatory protein, cofilin, into the nuclei. The effect was not associated with an increase in the proportion of apoptotic cells. The major part of the nuclear actin ... More
The promotive effect of latrunculin B on maize root gravitropism is concentration dependent.
AuthorsBlancaflor EB, Hou GC, Mohamalawari DR
JournalAdv Space Res
PubMed ID14686435
'The cytoskeleton has been proposed to be a key player in the gravitropic response of higher plants. A major approach to determine the role of the cytoskeleton in gravitropism has been to use inhibitors to disrupt the cytoskeleton and then to observe the effect that such disruption has on organ ... More
Intracellular magnetophoresis of statoliths in Chara rhizoids and analysis of cytoplasm viscoelasticity.
AuthorsKuznetsov OA, Hasenstein KH
JournalAdv Space Res
PubMed ID11594372
'The statoliths in Chara rhizoids are denser and more diamagnetic than the cytoplasm, therefore they can be displaced inside a living cell by a sufficiently strong high gradient magnetic field (HGMF). An experimental setup for intracellular magnetophoresis of statoliths was developed. The movement of statoliths and rhizoid growth was measured ... More
Glutamate and amyloid beta-protein rapidly inhibit fast axonal transport in cultured rat hippocampal neurons by different mechanisms.
AuthorsHiruma H, Katakura T, Takahashi S, Ichikawa T, Kawakami T
JournalJ Neurosci
PubMed ID14523099
'Impairment of axonal transport leads to neurodegeneration and synapse loss. Glutamate and amyloid beta-protein (Abeta) have critical roles in the pathogenesis of Alzheimer''s disease (AD). Here we show that both agents rapidly inhibit fast axonal transport in cultured rat hippocampal neurons. The effect of glutamate (100 microm), but not of ... More
The therapeutic effect of lipo PGE1 on diabetic neuropathy-changes in endothelin and various angiopathic factors.
AuthorsItoh Y, Yasui T, Kakizawa H, Makino M, Fujiwara K, Kato T, Imamura S, Yamamoto K, Hishida H, Nakai A, Itoh M, Nagasaka A
JournalProstaglandins Other Lipid Mediat
PubMed ID11577785
'A high blood concentration of endothelin (ET)-1 may participate in the onset and progress of diabetic microangiopathy, resulting in neuropathy. We examined the therapeutic effects of prostaglandin E1 (PGE1), which possesses both a peripheral vasodilating action and inhibition of platelet aggregation, on diabetic microangiopathy. Increases in both skin temperature and ... More
Evidence that actin and myosin are involved in the poleward flux of tubulin in metaphase kinetochore microtubules of crane-fly spermatocytes.
AuthorsSilverman-Gavrila RV, Forer A
JournalJ Cell Sci
PubMed ID10652253
'We studied the effects of various drugs on the poleward flux of tubulin in kinetochore microtubules in metaphase-I crane-fly spermatocytes. We used as a measure of tubulin flux a ''gap'' in acetylation of kinetochore microtubules immediately poleward from the kinetochore; the ''gap'' is caused by a time lag between incorporation ... More
Involvement of cellular cytoskeleton components in antibody-induced internalization of viral glycoproteins in pseudorabies virus-infected monocytes.
AuthorsVan de Walle GR, Favoreel HW, Nauwynck HJ, Van Oostveldt P, Pensaert MB
JournalVirology
PubMed ID11543665
'Addition of pseudorabies virus (PrV)-specific polyclonal immunoglobulins to PrV-infected monocytes induces internalization of plasma membrane-anchored viral glycoproteins and this may interfere with antibody-dependent cell lysis. We investigated the role of actin, microtubules, clathrin, and dynein, the major cellular components involved in physiological endocytosis during this virological internalization. Porcine monocytes were ... More
Dynacortin contributes to cortical viscoelasticity and helps define the shape changes of cytokinesis.
AuthorsGirard KD, Chaney C, Delannoy M, Kuo SC, Robinson DN
JournalEMBO J
PubMed ID15014435
'During cytokinesis, global and equatorial pathways deform the cell cortex in a stereotypical manner, which leads to daughter cell separation. Equatorial forces are largely generated by myosin-II and the actin crosslinker, cortexillin-I. In contrast, global mechanics are determined by the cortical cytoskeleton, including the actin crosslinker, dynacortin. We used direct ... More
Latrunculins' effects on intraocular pressure, aqueous humor flow, and corneal endothelium.
'PURPOSE: To determine the effects of latrunculin (LAT)-A or -B on intraocular pressure (IOP), aqueous humor flow (AHF), anterior chamber (AC) protein concentration ([protein]AC), corneal endothelial permeability and morphology, and corneal thickness in living cynomolgus monkeys. METHODS: Topical LAT-A or LAT-B was administered to one eye, and vehicle to the ... More
G(alpha)11 signaling through ARF6 regulates F-actin mobilization and GLUT4 glucose transporter translocation to the plasma membrane.
AuthorsBose A, Cherniack AD, Langille SE, Nicoloro SM, Buxton JM, Park JG, Chawla A, Czech MP
JournalMol Cell Biol
PubMed ID11438680
'The action of insulin to recruit the intracellular GLUT4 glucose transporter to the plasma membrane of 3T3-L1 adipocytes is mimicked by endothelin 1, which signals through trimeric G(alpha)q or G(alpha)11 proteins. Here we report that murine G(alpha)11 is most abundant in fat and that expression of the constitutively active form ... More
Differential effects of actin cytoskeleton dynamics on equine infectious anemia virus particle production.
'Retrovirus assembly and budding involve a highly dynamic and concerted interaction of viral and cellular proteins. Previous studies have shown that retroviral Gag proteins interact with actin filaments, but the significance of these interactions remains to be defined. Using equine infectious anemia virus (EIAV), we now demonstrate differential effects of ... More
LIM kinase and Diaphanous cooperate to regulate serum response factor and actin dynamics.
AuthorsGeneste O, Copeland JW, Treisman R
JournalJ Cell Biol
PubMed ID12034774
'The small GTPase RhoA controls activity of serum response factor (SRF) by inducing changes in actin dynamics. We show that in PC12 cells, activation of SRF after serum stimulation is RhoA dependent, requiring both actin polymerization and the Rho kinase (ROCK)-LIM kinase (LIMK)-cofilin signaling pathway, previously shown to control F-actin ... More
In vivo dynamics of the F-actin-binding protein neurabin-II.
AuthorsStephens DJ, Banting G
JournalBiochem J
PubMed ID10620493
'Neurabin-II (spinophilin) is a ubiquitously expressed F-actin-binding protein containing an N-terminal actin-binding domain, a PDZ (PSD95/discs large/ZO-1) domain and a C-terminal domain predicted to form a coiled-coil structure. We have stably expressed a green fluorescent protein (GFP)-tagged version of neurabin-II in PC12 cells, and characterized the in vivo dynamics of ... More
Stability of actin cytoskeleton and PKC-delta binding to actin regulate NKCC1 function in airway epithelial cells.
AuthorsLiedtke CM, Hubbard M, Wang X
JournalAm J Physiol Cell Physiol
PubMed ID12388079
'Activation of airway epithelial Na-K-2Cl cotransporter (NKCC)1 requires increased activity of protein kinase C (PKC)-delta, which localizes predominantly to the actin cytoskeleton. Prompted by reports of a role for actin in NKCC1 function, we studied a signaling mechanism linking NKCC1 and PKC. Stabilization of actin polymerization with jasplakinolide increased activity ... More
Rkp1/Cpc2, a fission yeast RACK1 homolog, is involved in actin cytoskeleton organization through protein kinase C, Pck2, signaling.
AuthorsWon M, Park SK, Hoe KL, Jang YJ, Chung KS, Kim DU, Kim HB, Yoo HS
JournalBiochem Biophys Res Commun
PubMed ID11263963
'The Rkp1/Cpc2, a fission yeast RACK1 homolog, interacted with Pck2, one of the known PKC homologs, in vivo and in vitro. The rkp1-deletion mutants (Deltarkp1) are elongated and the pck2-deletion mutant (Deltapck2) showed abnormal morphology. The double-deletion mutant (Deltarkp1Deltapck2) showed more aberrant cell shapes and was sensitive to high salt ... More
Cell wall deposition during morphogenesis in fucoid algae.
AuthorsBisgrove SR, Kropf DL
JournalPlanta
PubMed ID11346938
'Cell was deposition was investigated during morphogenesis in zygotes of Pelvetia compressa (J. Agardh) De Toni. Young zygotes are spherical and wall is deposited uniformly, but at germination (about 10 h after fertilization) wall deposition becomes localized to the apex of the tip-growing rhizoid. Wall deposition was investigated before and ... More
Insulin-stimulated GLUT4 translocation in adipocytes is dependent upon cortical actin remodeling.
AuthorsKanzaki M, Pessin JE
JournalJ Biol Chem
PubMed ID11546823
'Rhodamine-labeled phalloidin staining of morphologically differentiated 3T3L1 adipocytes demonstrated that F-actin predominantly exists juxtaposed to and lining the inner face of the plasma membrane (cortical actin) with a smaller amount of stress fiber and/or ruffling actin confined to the cell bottom in contact with the substratum. The extent of cortical ... More
Caught in the actin.
AuthorsMitchell A
JournalNat Rev Mol Cell Biol
PubMed ID11575274
Yeast vacuoles and membrane fusion pathways.
AuthorsWickner W
JournalEMBO J
PubMed ID11889030
Selective membrane fusion underlies subcellular compartmentation, cell growth, neurotransmission and hormone secretion. Its fundamental mechanisms are conserved among organelles, tissues and organisms. As befits a conserved process, reductionism led to its study in microorganisms. Homotypic fusion of the vacuole of Saccharomyces cerevisiae is particularly accessible to study as vacuoles are ... More
Nanotubular highways for intercellular organelle transport.
AuthorsRustom A, Saffrich R, Markovic I, Walther P, Gerdes HH
JournalScience
PubMed ID14963329
Cell-to-cell communication is a crucial prerequisite for the development and maintenance of multicellular organisms. To date, diverse mechanisms of intercellular exchange of information have been documented, including chemical synapses, gap junctions, and plasmodesmata. Here, we describe highly sensitive nanotubular structures formed de novo between cells that create complex networks. These ... More
Actin polymerization-driven molecular movement of mDia1 in living cells.
AuthorsHigashida C, Miyoshi T, Fujita A, Oceguera-Yanez F, Monypenny J, Andou Y, Narumiya S, Watanabe N
JournalScience
PubMed ID15044801
mDia1, a Rho effector, belongs to the Formin family of proteins, which shares the conserved tandem FH1-FH2 unit structure. Formins including mDia1 accelerate actin nucleation while interacting with actin filament fast-growing ends. Here our single-molecule imaging revealed fast directional movement of mDia1 FH1-FH2 for tens of microns in living cells. ... More
Effect of latrunculin-B on outflow facility in monkeys.
AuthorsPeterson JA, Tian B, Geiger B, Kaufman PL
JournalExp Eye Res
PubMed ID10712817
Latrunculin-B (LAT-B), a macrolide derived from the marine sponge Latrunculia magnifica, sequesters monomeric G-actin, leading to the disassembly of actin filaments in cultured cells. In this study, we determined the effect of LAT-B on outflow facility in living monkeys. Total outflow facility was measured by 2-level constant pressure perfusion of ... More
GLUT4 translocation by insulin in intact muscle cells: detection by a fast and quantitative assay.
AuthorsWang Q, Khayat Z, Kishi K, Ebina Y, Klip A
JournalFEBS Lett
PubMed ID9607310
We report a rapid and sensitive colorimetric approach to quantitate the amount of glucose transporters exposed at the surface of intact cells, using L6 muscle cells expressing GLUT4 containing an exofacial myc epitope. Unstimulated cells exposed to the surface 5 fmol GLUT4myc per mg protein. This value increased to 10 ... More
Actin-binding protein, supervillin, has been identified as an androgen receptor (AR) coregulator. Although actin has been suggested to participate in transcription regulation, the mechanism is not clear. Here we demonstrate signals involved in the cytoskeleton dynamic can modulate the coregulator function of supervillin. Three actin isoforms cooperate with supervillin in ... More
EHD2 and the novel EH domain binding protein EHBP1 couple endocytosis to the actin cytoskeleton.
AuthorsGuilherme A, Soriano NA, Bose S, Holik J, Bose A, Pomerleau DP, Furcinitti P, Leszyk J, Corvera S, Czech MP
JournalJ Biol Chem
PubMed ID14676205
Here we identified two novel proteins denoted EH domain protein 2 (EHD2) and EHD2-binding protein 1 (EHBP1) that link clathrin-mediated endocytosis to the actin cytoskeleton. EHD2 contains an N-terminal P-loop and a C-terminal EH domain that interacts with NPF repeats in EHBP1. Disruption of EHD2 or EHBP1 function by small ... More
Monitoring Dynamic GPCR Signaling Events Using Fluorescence Microscopy, FRET Imaging, and Single-Molecule Imaging.
AuthorsXu X, Brzostowski JA, Jin T,
JournalMethods Mol Biol
PubMed ID19763980
How a eukaryotic cell translates a small concentration difference of a chemoattractant across the length of its surface into highly polarized intracellular responses is a fundamental question in chemotaxis. Chemoattractants are detected by G-protein-coupled receptors (GPCRs). Binding of chemoattractants to GPCRs induces the dissociation of heterotrimeric G-proteins into Galpha and ... More
p53-cofactor JMY is a multifunctional actin nucleation factor.
Many cellular structures are assembled from networks of actin filaments, and the architecture of these networks depends on the mechanism by which the filaments are formed. Several classes of proteins are known to assemble new filaments, including the Arp2/3 complex, which creates branched filament networks, and Spire, which creates unbranched ... More
High-content phenotypic profiling of drug response signatures across distinct cancer cells.
AuthorsCaie PD, Walls RE, Ingleston-Orme A, Daya S, Houslay T, Eagle R, Roberts ME, Carragher NO,
JournalMol Cancer Ther
PubMed ID20530715
The application of high-content imaging in conjunction with multivariate clustering techniques has recently shown value in the confirmation of cellular activity and further characterization of drug mode of action following pharmacologic perturbation. However, such practical examples of phenotypic profiling of drug response published to date have largely been restricted to ... More