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
Specification of actin filament function and molecular composition by tropomyosin isoforms.
The specific functions of greater than 40 vertebrate nonmuscle tropomyosins (Tms) are poorly understood. In this article we have tested the ability of two Tm isoforms, TmBr3 and the human homologue of Tm5 (hTM5(NM1)), to regulate actin filament function. We found that these Tms can differentially alter actin filament organization, ... More
Actin filament cross-linking by MARCKS: characterization of two actin-binding sites within the phosphorylation site domain.
AuthorsYarmola EG, Edison AS, Lenox RH, Bubb MR
JournalJ Biol Chem
PubMed ID11294839
We recently identified conformational changes that occur upon phosphorylation of myristoylated alanine-rich protein kinase C substrate (MARCKS) that preclude efficient cross-linking of actin filaments (Bubb, M. R., Lenox, R. H., and Edison, A. S. (1999) J. Biol. Chem. 274, 36472-36478). These results implied that the phosphorylation site domain of MARCKS ... More
Actin filament turnover removes bundles from Drosophila bristle cells.
AuthorsGuild GM, Connelly PS, Vranich KA, Shaw MK, Tilney LG
JournalJ Cell Sci
PubMed ID11861770
Drosophila bristle cells form enormous extensions that are supported by equally impressive scaffolds of modular, polarized and crosslinked actin filament bundles. As the cell matures and support is taken over by the secreted cuticle, the actin scaffold is completely removed. This removal begins during cell elongation and proceeds via an ... More
Gelsolin mediates collagen phagocytosis through a rac-dependent step.
AuthorsArora PD, Glogauer M, Kapus A, Kwiatkowski DJ, McCulloch CA
JournalMol Biol Cell
PubMed ID14617805
The role of gelsolin, a calcium-dependent actin-severing protein, in mediating collagen phagocytosis, is not defined. We examined alpha 2 beta 1 integrin-mediated phagocytosis in fibroblasts from wild-type (WT) and gelsolin knockout (Gsn(-)) mice. After initial contact with collagen beads, collagen binding and internalization were 60% lower in Gsn(-) than WT ... More
Tracking of quantum dot-labeled CFTR shows near immobilization by C-terminal PDZ interactions.
AuthorsHaggie PM, Kim JK, Lukacs GL, Verkman AS
JournalMol Biol Cell
PubMed ID16987954
'Mutations in cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-regulated chloride channel, cause cystic fibrosis. To investigate interactions of CFTR in living cells, we measured the diffusion of quantum dot-labeled CFTR molecules by single particle tracking. In multiple cell lines, including airway epithelia, CFTR diffused little in the plasma membrane, ... More
A small-molecule approach to studying invasive mechanisms of Toxoplasma gondii.
AuthorsCarey KL, Westwood NJ, Mitchison TJ, Ward GE
JournalProc Natl Acad Sci U S A
PubMed ID15123807
'Toxoplasma gondii is the most common protozoan parasite of humans. Infection with T. gondii can lead to life-threatening disease as a result of repeated cycles of host cell invasion, parasite replication, and host cell lysis. Relatively little is known about the invasive mechanisms of T. gondii and related parasites within ... More
The platelet cytoskeleton regulates the affinity of the integrin alpha(IIb)beta(3) for fibrinogen.
AuthorsBennett JS, Zigmond S, Vilaire G, Cunningham ME, Bednar B
JournalJ Biol Chem
PubMed ID10464255
'Agonist-generated inside-out signals enable the platelet integrin alpha(IIb)beta(3) to bind soluble ligands such as fibrinogen. We found that inhibiting actin polymerization in unstimulated platelets with cytochalasin D or latrunculin A mimics the effects of platelet agonists by inducing fibrinogen binding to alpha(IIb)beta(3). By contrast, stabilizing actin filaments with jasplakinolide prevented ... More
Stimulation of fascin spikes by thrombospondin-1 is mediated by the GTPases Rac and Cdc42.
AuthorsAdams JC, Schwartz MA
JournalJ Cell Biol
PubMed ID10953005
'Cell adhesion to extracellular matrix is an important physiological stimulus for organization of the actin-based cytoskeleton. Adhesion to the matrix glycoprotein thrombospondin-1 (TSP-1) triggers the sustained formation of F-actin microspikes that contain the actin-bundling protein fascin. These structures are also implicated in cell migration, which may be an important function ... More
Lipid rafts in the maintenance of synapses, dendritic spines, and surface AMPA receptor stability.
AuthorsHering H, Lin CC, Sheng M
JournalJ Neurosci
PubMed ID12716933
'Cholesterol/sphingolipid microdomains (lipid rafts) in the membrane are involved in protein trafficking, formation of signaling complexes, and regulation of actin cytoskeleton. Here, we show that lipid rafts exist abundantly in dendrites of cultured hippocampal neurons, in which they are associated with several postsynaptic proteins including surface AMPA receptors. Depletion of ... 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
Growth modulation and differentiation of acute myeloid leukemia cells by jaspamide.
AuthorsFabian I, Shur I, Bleiberg I, Rudi A, Kashman Y, Lishner M
JournalExp Hematol
PubMed ID7601248
'We have examined the effect of Jaspamide, a peptide isolated from the marine sponge Hemiastrella minor, on in vitro proliferation and differentiation of leukemic cell lines and blast cells of three AML patients and compared it to that of cytosine arabinoside (ARA-C). The biological properties were studied in two complementary ... More
Regulation of sustained actin dynamics by the TCR and costimulation as a mechanism of receptor localization.
AuthorsTskvitaria-Fuller I, Rozelle AL, Yin HL, Wülfing C
JournalJ Immunol
PubMed ID12928373
'The localization of receptors, signaling intermediates, and cytoskeletal components at the T cell/APC interface is thought to be a major determinant of efficient T cell activation. However, important questions remain open. What are the dynamics of the T cell cytoskeleton as a potential mediator of such localization? How are they ... More
Glucose release from GLUT2-null hepatocytes: characterization of a major and a minor pathway.
AuthorsHosokawa M, Thorens B
JournalAm J Physiol Endocrinol Metab
PubMed ID11882499
'We previously reported that glucose can be released from GLUT2-null hepatocytes through a membrane traffic-based pathway issued from the endoplasmic reticulum. Here, we further characterized this glucose release mechanism using biosynthetic labeling protocols. In continuous pulse-labeling experiments, we determined that glucose secretion proceeded linearly and with the same kinetics in ... More
Cell-specific behavior of P2X7 receptors in mouse parotid acinar and duct cells.
AuthorsLi Q, Luo X, Zeng W, Muallem S
JournalJ Biol Chem
PubMed ID12968021
'P2X7 receptors (P2X7Rs) affect many epithelial cell functions including transcellular ion transport, secretion, and cell death. Here we used parotid acinar and duct cells to reveal the unique cell-specific assembly and gating of the P2X7R channels. Immunolocalization indicated expression of P2X7Rs in the luminal membrane of both cell types. Stimulation ... More
Requirement of Rac activity for maintenance of capillary endothelial barrier properties.
AuthorsWaschke J, Baumgartner W, Adamson RH, Zeng M, Aktories K, Barth H, Wilde C, Curry FE, Drenckhahn D
JournalAm J Physiol Heart Circ Physiol
PubMed ID14512275
'Our previous experiments indicated that GTPases, other than RhoA, are important for the maintenance of endothelial barrier integrity in both intact microvessels of rats and mice and cultured mouse myocardial endothelial (MyEnd) cell monolayers. In the present study, we inhibited the endothelial GTPase Rac by Clostridium sordellii lethal toxin (LT) ... More
Jasplakinolide: interaction with radiation and hyperthermia in human prostate carcinoma and Lewis lung carcinoma.
AuthorsTakeuchi H, Ara G, Sausville EA, Teicher B
JournalCancer Chemother Pharmacol
PubMed ID9788576
'PURPOSE: Jasplakinolide is a novel natural product anticancer agent which acts by inducing overpolymerization of actin. The aim of the current study was to explore the activity of jasplakinolide with hyperthermia and radiation. METHODS: The response of human PC-3 and DU-145 prostate carcinoma cells and DU-145 xenografts and the response ... More
beta1 integrin and organized actin filaments facilitate cardiomyocyte-specific RhoA-dependent activation of the skeletal alpha-actin promoter.
AuthorsWei L, Wang L, Carson JA, Agan JE, Imanaka-Yoshida K, Schwartz RJ
JournalFASEB J
PubMed ID11259397
'Activation of RhoA GTPase causes actin filament bundling into stress fibers, integrin clustering, and focal adhesion formation through its action on actin cytoskeleton organization. RhoA also regulates transcriptional activity of serum response factor (SRF). Recent studies in NIH 3T3 fibroblasts have shown that SRF activation by RhoA does not require ... More
Facilitation of Ca(2+)-dependent exocytosis by Rac1-GTPase in bovine chromaffin cells.
AuthorsLi Q, Ho CS, Marinescu V, Bhatti H, Bokoch GM, Ernst SA, Holz RW, Stuenkel EL
JournalJ Physiol
PubMed ID12754309
'Rho family GTPases are primary mediators of cytoskeletal reorganization, although they have also been reported to regulate cell secretion. Yet, the extent to which Rho family GTPases are activated by secretory stimuli in neural and neuroendocrine cells remains unknown. In bovine adrenal chromaffin cells, we found Rac1, but not Cdc42, ... More
Function of alpha3beta1-tetraspanin protein complexes in tumor cell invasion. Evidence for the role of the complexes in production of matrix metalloproteinase 2 (MMP-2).
AuthorsSugiura T, Berditchevski F
JournalJ Cell Biol
PubMed ID10491398
'Tumor cell migration through the three- dimensional extracellular matrix (ECM) environment is an important part of the metastatic process. We have analyzed a role played by the integrin-tetraspanin protein complexes in invasive migration by culturing MDA-MB-231 cells within Matrigel. Using time-lapse video recording, we demonstrated that the Matrigel-embedded cells remain ... More
Sla1p couples the yeast endocytic machinery to proteins regulating actin dynamics.
'Sla1p is a protein required for cortical actin patch structure and organisation in budding yeast. Here we use a combination of immunofluorescence microscopy and biochemical approaches to demonstrate interactions of Sla1p both with proteins regulating actin dynamics and with proteins required for endocytosis. Using Sla1p-binding studies we reveal association of ... More
The M-phase-promoting factor modulates the sensitivity of the Ca2+ stores to inositol 1,4,5-trisphosphate via the actin cytoskeleton.
AuthorsLim D, Ercolano E, Kyozuka K, Nusco GA, Moccia F, Lange K, Santella L
JournalJ Biol Chem
PubMed ID12867432
'The resumption of the meiotic cycle (maturation) induced by 1-methyladenine in prophase-arrested starfish oocytes is indicated by the breakdown of the germinal vesicle and is characterized by the increased sensitivity of the Ca2+ stores to inositol 1,4,5-trisphosphate (InsP3) to InsP3 starting at the animal hemisphere (where the germinal vesicle was ... More
Two pathways for store-mediated calcium entry differentially dependent on the actin cytoskeleton in human platelets.
'A major pathway for stimulated Ca(2+) entry in non-excitable cells is activated following depletion of intracellular Ca(2+) stores. Secretion-like coupling between elements in the plasma membrane (PM) and Ca(2+) stores has been proposed as the most likely mechanism to activate this store-mediated Ca(2+) entry (SMCE) in several cell types. Here ... More
Phosphatidylinositol 4,5-bisphosphate functions as a second messenger that regulates cytoskeleton-plasma membrane adhesion.
AuthorsRaucher D, Stauffer T, Chen W, Shen K, Guo S, York JD, Sheetz MP, Meyer T
JournalCell
PubMed ID10660045
'Binding interactions between the plasma membrane and the cytoskeleton define cell functions such as cell shape, formation of cell processes, cell movement, and endocytosis. Here we use optical tweezers tether force measurements and show that plasma membrane phosphatidylinositol 4,5-bisphosphate (PIP2) acts as a second messenger that regulates the adhesion energy ... 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
Single-particle tracking of murine polyoma virus-like particles on live cells and artificial membranes.
AuthorsEwers H, Smith AE, Sbalzarini IF, Lilie H, Koumoutsakos P, Helenius A
JournalProc Natl Acad Sci U S A
PubMed ID16219700
'The lateral mobility of individual murine polyoma virus-like particles (VLPs) bound to live cells and artificial lipid bilayers was studied by single fluorescent particle tracking using total internal reflection fluorescence microscopy. The particle trajectories were analyzed in terms of diffusion rates and modes of motion as described by the moment ... More
SRF regulates Bcl-2 expression and promotes cell survival during murine embryonic development.
AuthorsSchratt G, Philippar U, Hockemeyer D, Schwarz H, Alberti S, Nordheim A
JournalEMBO J
PubMed ID15057274
'The transcription factor serum response factor (SRF) controls the expression of genes involved in cellular proliferation and differentiation. Interestingly, SRF also promotes cell survival by regulating the expression of antiapoptotic genes. In in vitro differentiating murine embryonic stem (ES) cells, SRF deficiency leads to increased apoptosis. Loss of SRF correlates ... More
Yeast osmosensor Sln1 and plant cytokinin receptor Cre1 respond to changes in turgor pressure.
AuthorsReiser V, Raitt DC, Saito H
JournalJ Cell Biol
PubMed ID12821642
'Very little is known about how cellular osmosensors monitor changes in osmolarity of the environment. Here, we report that in yeast, Sln1 osmosensor histidine kinase monitors changes in turgor pressures. Reductions in turgor caused by either hyperosmotic stress, nystatin, or removal of cell wall activate MAPK Hog1 specifically through the ... More
Pressure-induced actin polymerization in vascular smooth muscle as a mechanism underlying myogenic behavior.
AuthorsCipolla MJ, Gokina NI, Osol G
JournalFASEB J
PubMed ID11772938
'We hypothesize that actin polymerization within vascular smooth muscle (VSM) in response to increased intravascular pressure is a novel and previously unrecognized mechanism underlying arterial myogenic behavior. This hypothesis is based on the following observations. 1) Unlike skeletal or cardiac muscle, VSM contains a substantial pool of unpolymerized globular (G) ... 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
Specific isoforms of actin-binding proteins on distinct populations of Golgi-derived vesicles.
'Golgi membranes and Golgi-derived vesicles are associated with multiple cytoskeletal proteins and motors, the diversity and distribution of which have not yet been defined. Carrier vesicles were separated from Golgi membranes, using an in vitro budding assay, and different populations of vesicles were separated using sucrose density gradients. Three main ... More
Signaling through integrin LFA-1 leads to filamentous actin polymerization and remodeling, resulting in enhanced T cell adhesion.
AuthorsPorter JC, Bracke M, Smith A, Davies D, Hogg N
JournalJ Immunol
PubMed ID12055249
'The integrins can activate signaling pathways, but the final downstream outcome of these pathways is often unclear. This study analyzes the consequences of signaling events initiated by the interaction of the leukocyte integrin LFA-1 with its ligand, dimeric ICAM-1. We show that the active form of LFA-1 regulates its own ... More
Spatial regulation of actin dynamics: a tropomyosin-free, actin-rich compartment at the leading edge.
AuthorsDesMarais V, Ichetovkin I, Condeelis J, Hitchcock-DeGregori SE
JournalJ Cell Sci
PubMed ID12415009
'Rapid polymerization of a network of short, branched actin filaments takes place at the leading edge of migrating cells, a compartment enriched in activators of actin polymerization such as the Arp2/3 complex and cofilin. Actin filaments elsewhere in the cell are long and unbranched. Results reported here show that the ... More
A balance of capping protein and profilin functions is required to regulate actin polymerization in Drosophila bristle.
AuthorsHopmann R, Miller KG
JournalMol Biol Cell
PubMed ID12529431
'Profilin is a well-characterized protein known to be important for regulating actin filament assembly. Relatively few studies have addressed how profilin interacts with other actin-binding proteins in vivo to regulate assembly of complex actin structures. To investigate the function of profilin in the context of a differentiating cell, we have ... 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
Ly6C induces clustering of LFA-1 (CD11a/CD18) and is involved in subtype-specific adhesion of CD8 T cells.
AuthorsJaakkola I, Merinen M, Jalkanen S, Hänninen A
JournalJ Immunol
PubMed ID12538687
'Ly6C is a hemopoietic cell differentiation Ag found on a subset of CD8 T cells in the periphery. It is involved in target cell killing by CTLs, augments TCR-mediated activation of IL-2 and IFN-gamma production in CD8 T cells, and regulates CD8 T cell homing in vivo. In this study, ... 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
Cofilin promotes stimulus-induced lamellipodium formation by generating an abundant supply of actin monomers.
AuthorsKiuchi T, Ohashi K, Kurita S, Mizuno K
JournalJ Cell Biol
PubMed ID17470633
'Cofilin stimulates actin filament disassembly and accelerates actin filament turnover. Cofilin is also involved in stimulus-induced actin filament assembly during lamellipodium formation. However, it is not clear whether this occurs by replenishing the actin monomer pool, through filament disassembly, or by creating free barbed ends, through its severing activity. Using ... More
Overexpression of myosin IB in living Entamoeba histolytica enhances cytoplasm viscosity and reduces phagocytosis.
AuthorsMarion S, Wilhelm C, Voigt H, Bacri JC, Guillén N
JournalJ Cell Sci
PubMed ID15226399
'The human parasite Entamoeba histolytica is an ancient protozoan that expresses only one unconventional myosin, which has homology with myosin IB from other amoebae. Myosin IB is involved in phagocytosis of human cells by E. histolytica. In this work, we developed a microrheological technique, analysing magnetic phagosomes, which allowed us ... More
Endogenously expressed Trp1 is involved in store-mediated Ca2+ entry by conformational coupling in human platelets.
AuthorsRosado JA, Brownlow SL, Sage SO
JournalJ Biol Chem
PubMed ID12196544
'Physical interaction between transient receptor potential (Trp) channels and inositol 1,4,5-trisphosphate receptors (IP(3)Rs) has been presented as a candidate mechanism for the activation of store-mediated Ca(2+) entry. The role of a human homologue of Drosophila transient receptor potential channel, hTrp1, in the conduction of store-mediated Ca(2+) entry was examined in ... More
Stepwise cytoskeletal polarization as a series of checkpoints in innate but not adaptive cytolytic killing.
AuthorsWulfing C, Purtic B, Klem J, Schatzle JD
JournalProc Natl Acad Sci U S A
PubMed ID12802007
'Cytolytic killing is a major effector mechanism in the elimination of virally infected and tumor cells. The innate cytolytic effectors, natural killer (NK) cells, and the adaptive effectors, cytotoxic T cells (CTL), despite differential immune recognition, both use the same lytic mechanism, cytolytic granule release. Using live cell video fluorescence ... More
Cellular regulation of sodium-calcium exchange.
AuthorsCondrescu M, Opuni K, Hantash BM, Reeves JP
JournalAnn N Y Acad Sci
PubMed ID12502564
'Na(+)/Ca(2+) exchange activity was studied in transfected Chinese hamster ovary (CHO) cells expressing the wild-type cardiac exchanger (NCX1.1) or mutants created by site-directed mutagenesis. The activity of the wild-type exchanger, but not exchanger mutants deficient in Ca(2+)-dependent activation, was inhibited by sphingolipids such as ceramide and sphingosine. We propose that ... More
The diaphanous-related formin mDia1 controls serum response factor activity through its effects on actin polymerization.
AuthorsCopeland JW, Treisman R
JournalMol Biol Cell
PubMed ID12429848
'SRF-dependent transcription is regulated by the small GTPase RhoA via its effects on actin dynamics. The diaphanous-related formin (DRF) proteins have been identified as candidate RhoA effectors mediating signaling to SRF. Here we investigate the relationship between SRF activation and actin polymerization by the DRF mDia1. We show that the ... 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
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
Contribution of cytoskeleton to the internalization of AMPA receptors.
AuthorsZhou Q, Xiao M, Nicoll RA
JournalProc Natl Acad Sci U S A
PubMed ID11158627
'Trafficking of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPARs) at synapses has been suggested to play an important role in the expression of synaptic plasticity. Both the regulated and the constitutive trafficking of synaptic AMPARs are thought to involve the insertion and removal of receptors by means of an exocytotic and endocytotic ... More
Hypertonicity-induced projections reflect cell polarity in mouse metaphase II oocytes: involvement of microtubules, microfilaments, and chromosomes.
AuthorsLiu JL, Sung LY, Tian XC, Yang X
JournalBiol Reprod
PubMed ID12444063
'A previous study showed that with hypertonic sucrose treatment, a projection is formed in mouse metaphase II (MII) oocytes in proximity to the spindle and chromosomes, where a polarized cortical domain is located. However, little is known about the mechanisms involved in this process. Here, we designed a series of ... More
Pollen tubes exhibit regular periodic membrane trafficking events in the absence of apical extension.
'The growing pollen tube provides an excellent single cell model system in which to study the mechanisms determining growth regulation, polarity and periodic behaviour. Previously, using FM4-64, we identified periodic movements within the apical vesicle accumulation that were related to the period of oscillatory growth. This suggested a more complex ... More
Role for actin filament turnover and a myosin II motor in cytoskeleton-driven disassembly of the epithelial apical junctional complex.
AuthorsIvanov AI, McCall IC, Parkos CA, Nusrat A
JournalMol Biol Cell
PubMed ID15047870
'Disassembly of the epithelial apical junctional complex (AJC), composed of the tight junction (TJ) and adherens junction (AJ), is important for normal tissue remodeling and pathogen-induced disruption of epithelial barriers. Using a calcium depletion model in T84 epithelial cells, we previously found that disassembly of the AJC results in endocytosis ... More
Vacuolar H+-ATPase binding to microfilaments: regulation in response to phosphatidylinositol 3-kinase activity and detailed characterization of the actin-binding site in subunit B.
AuthorsChen SH, Bubb MR, Yarmola EG, Zuo J, Jiang J, Lee BS, Lu M, Gluck SL, Hurst IR, Holliday LS
JournalJ Biol Chem
PubMed ID14662773
'Vacuolar H(+)-ATPase (V-ATPase) binds microfilaments, and that interaction may be mediated by an actin binding domain in subunit B of the enzyme. To test for possible physiologic functions of the actin binding activity of V-ATPase, early responses of resorbing osteoclasts to inhibition of phosphatidylinositol 3-kinase activity by wortmannin and LY294002 ... More
Single cell mechanotransduction and its modulation analyzed by atomic force microscope indentation.
AuthorsCharras GT, Horton MA
JournalBiophys J
PubMed ID12023220
'The skeleton adapts to its mechanical usage, although at the cellular level, the distribution and magnitude of strains generated and their detection are ill-understood. The magnitude and nature of the strains to which cells respond were investigated using an atomic force microscope (AFM) as a microindentor. A confocal microscope linked ... More
Protein phosphatases 1 and 2A transiently associate with myosin during the peak rate of secretion from mast cells.
AuthorsHolst J, Sim AT, Ludowyke RI
JournalMol Biol Cell
PubMed ID11907284
'Mast cells undergo cytoskeletal restructuring to allow secretory granules passage through the cortical actomyosin barrier to fuse with the plasma membrane and release inflammatory mediators. Protein phosphorylation is believed to regulate these rearrangements. Although some of the protein kinases implicated in this phosphorylation are known, the relevant protein phosphatases are ... More
Neocentromere-mediated chromosome movement in maize.
AuthorsYu HG, Hiatt EN, Chan A, Sweeney M, Dawe RK
JournalJ Cell Biol
PubMed ID9362502
'Neocentromere activity is a classic example of nonkinetochore chromosome movement. In maize, neocentromeres are induced by a gene or genes on Abnormal chromosome 10 (Ab10) which causes heterochromatic knobs to move poleward at meiotic anaphase. Here we describe experiments that test how neocentromere activity affects the function of linked centromere/kinetochores ... 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
HIV-1 cell to cell transfer across an Env-induced, actin-dependent synapse.
AuthorsJolly C, Kashefi K, Hollinshead M, Sattentau QJ
JournalJ Exp Med
PubMed ID14734528
'Direct cell-cell transfer is an efficient mechanism of viral dissemination within an infected host, and human immunodeficiency virus 1 (HIV-1) can exploit this mode of spread. Receptor recognition by HIV-1 occurs via interactions between the viral surface envelope glycoprotein (Env), gp120, and CD4 and a chemokine receptor, CCR5 or CXCR4. ... More
Actin disruption inhibits bombesin stimulation of focal adhesion kinase (pp125FAK) in prostate carcinoma.
AuthorsDuncan MD, Harmon JW, Duncan LK
JournalJ Surg Res
PubMed ID8661226
'Jasplakinolide is a member of a new class of antitumor agents targeting the actin cytoskeleton with activity against prostate cancer. Focal adhesion kinase (FAK) is an actin-associated mediator of mitogenic peptides. We hypothesized that the neuropeptide bombesin would activate FAR in prostate carcinoma, and that disruption of the actin network ... More
Actin coating of secretory granules during regulated exocytosis correlates with the release of rab3D.
'The present study describes a novel phenomenon in pancreatic acinar cells undergoing regulated exocytosis. When acinar cell preparations were challenged with the secretagogue carbamylcholine, a subpopulation of zymogen granules became coated with filamentous actin. These zymogen granules were always in proximity of the acinar cell apical membrane (the site of ... More
Cell penetration and trafficking of polyomavirus.
AuthorsGilbert JM, Goldberg IG, Benjamin TL
JournalJ Virol
PubMed ID12552000
'The murine polyomavirus (Py) enters mouse fibroblasts and kidney epithelial cells via an endocytic pathway that is caveola-independent (as well as clathrin-independent). In contrast, uptake of simian virus 40 into the same cells is dependent on caveola. Following the initial uptake of Py, both microtubules and microfilaments play roles in ... More
Differential usage of signal transduction pathways defines two types of serum response factor target gene.
AuthorsGineitis D, Treisman R
JournalJ Biol Chem
PubMed ID11342553
'Activation of the transcription factor serum response factor (SRF) is dependent on Rho-controlled changes in actin dynamics. We used pathway-specific inhibitors to compare the roles of actin dynamics, extracellular signal-regulated kinase (ERK) signaling, and phosphatidylinositol 3-kinase in signaling either to SRF itself or to four cellular SRF target genes. Serum, ... More
Increased diffusional mobility of CFTR at the plasma membrane after deletion of its C-terminal PDZ binding motif.
AuthorsHaggie PM, Stanton BA, Verkman AS
JournalJ Biol Chem
PubMed ID14660592
'The cystic fibrosis transmembrane conductance regulator (CFTR) protein is a cAMP-regulated Cl- channel expressed at the apical plasma membrane. It has been proposed that the C-terminal PDZ binding motif of CFTR is required for its apical membrane targeting and that PDZ-domain interactions may tether CFTR to the actin cytoskeleton via ... More
Microvilli appear to represent the first step in actin bundle formation in Drosophila bristles.
AuthorsTilney LG, Connelly PS, Guild GM
JournalJ Cell Sci
PubMed ID15226373
'During bristle development the emerging bristle shaft, socket cell, and the apical surface of thoracic epithelial cells form tiny protuberances or pimples that contain electron-dense material located on the cytoplasmic surface of the pimple tip. In a few cases short actin filaments extend from this material into the cortical cytoplasm. ... More
New class of antifungal agents: jasplakinolide, a cyclodepsipeptide from the marine sponge, Jaspis species.
AuthorsScott VR, Boehme R, Matthews TR
JournalAntimicrob Agents Chemother
PubMed ID3190203
'Jasplakinolide is a cyclodepsipeptide which represents a new class of antifungal agents with potent activity against Candida albicans. Jasplakinolide is fungicidal against C. albicans with both a MIC and a minimum lethal concentration of 25 micrograms/ml in a broth dilution assay. This activity compares to that of the imidazole miconazole ... 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
Fibronectin polymerization regulates the composition and stability of extracellular matrix fibrils and cell-matrix adhesions.
AuthorsSottile J, Hocking DC
JournalMol Biol Cell
PubMed ID12388756
'Remodeling of extracellular matrices occurs during development, wound healing, and in a variety of pathological processes including atherosclerosis, ischemic injury, and angiogenesis. Thus, identifying factors that control the balance between matrix deposition and degradation during tissue remodeling is essential for understanding mechanisms that regulate a variety of normal and pathological ... 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
LFA-1-mediated adhesion is regulated by cytoskeletal restraint and by a Ca2+-dependent protease, calpain.
AuthorsStewart MP, McDowall A, Hogg N
JournalJ Cell Biol
PubMed ID9456328
'The activity of integrins on leukocytes is kept under tight control to avoid inappropriate adhesion while these cells are circulating in blood or migrating through tissues. Using lymphocyte function-associated antigen-1 (LFA-1) on T cells as a model, we have investigated adhesion to ligand intercellular adhesion molecule-1 induced by the Ca2+ ... 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
Induction of an acrosomal process in Toxoplasma gondii: visualization of actin filaments in a protozoan parasite.
AuthorsShaw MK, Tilney LG
JournalProc Natl Acad Sci U S A
PubMed ID10430901
'The invasive stages of Toxoplasma gondii, an Apicomplexan parasite, actively invade their host cells in an actin-dependent way. However, despite containing biochemically significant amounts of actin, actin filaments have never been observed in these parasites. Jasplakinolide, a membrane-permeable actin-polymerizing and filament-stabilizing drug, induced the polymerization of actin filaments at the ... More
Actin filament turnover regulated by cross-linking accounts for the size, shape, location, and number of actin bundles in Drosophila bristles.
AuthorsTilney LG, Connelly PS, Ruggiero L, Vranich KA, Guild GM
JournalMol Biol Cell
PubMed ID14517310
'Drosophila bristle cells are shaped during growth by longitudinal bundles of cross-linked actin filaments attached to the plasma membrane. We used confocal and electron microscopy to examine actin bundle structure and found that during bristle elongation, snarls of uncross-linked actin filaments and small internal bundles also form in the shaft ... More
Protein kinase C regulates endocytosis and recycling of E-cadherin.
AuthorsLe TL, Joseph SR, Yap AS, Stow JL
JournalAm J Physiol Cell Physiol
PubMed ID12107059
'E-cadherin is a major component of adherens junctions in epithelial cells. We showed previously that a pool of cell surface E-cadherin is constitutively internalized and recycled back to the surface. In the present study, we investigated the potential role of protein kinase C (PKC) in regulating the trafficking of surface ... More
Macrophage podosomes assemble at the leading lamella by growth and fragmentation.
AuthorsEvans JG, Correia I, Krasavina O, Watson N, Matsudaira P
JournalJ Cell Biol
PubMed ID12756237
'Podosomes are actin- and fimbrin-containing adhesions at the leading edge of macrophages. In cells transfected with beta-actin-ECFP and L-fimbrin-EYFP, quantitative four-dimensional microscopy of podosome assembly shows that new adhesions arise at the cell periphery by one of two mechanisms; de novo podosome assembly, or fission of a precursor podosome into ... More
Actin stabilization by jasplakinolide enhances apoptosis induced by cytokine deprivation.
AuthorsPosey SC, Bierer BE
JournalJ Biol Chem
PubMed ID9933626
'Participation of the actin cytoskeleton in the transduction of proliferative signals has been established through the use of compounds that disrupt the cytoskeleton. To address the possibility that actin also participates in the transduction of an apoptotic signal, we have studied the response of the murine interleukin 2 (IL-2)-dependent T ... More
Cell survival, DNA damage, and oncogenic transformation after a transient and reversible apoptotic response.
AuthorsTang HL, Tang HM, Mak KH, Hu S, Wang SS, Wong KM, Wong CS, Wu HY, Law HT, Liu K, Talbot CC, Lau WK, Montell DJ, Fung MC,
JournalMol Biol Cell
PubMed ID22535522
'Apoptosis serves as a protective mechanism by eliminating damaged cells through programmed cell death. After apoptotic cells pass critical checkpoints, including mitochondrial fragmentation, executioner caspase activation, and DNA damage, it is assumed that cell death inevitably follows. However, this assumption has not been tested directly. Here we report an unexpected ... More
NO inhibits stretch-induced MAPK activity by cytoskeletal disruption.
AuthorsIngram AJ, James L, Cai L, Thai K, Ly H, Scholey JW
JournalJ Biol Chem
PubMed ID10984494
'Mesangial cells (MC) grown on extracellular matrix protein-coated plates and exposed to cyclic strain/relaxation proliferate and produce extracellular matrix protein, providing an in vitro model of signaling in stretched MC. Intracellular transduction of mechanical strain involves mitogen-activated protein kinases, and we have shown that p42/44 mitogen-activated protein kinase (extracellular signal-regulated ... More
A simple model for the cooperative stabilisation of actin filaments by phalloidin and jasplakinolide.
AuthorsVisegrády B, Lorinczy D, Hild G, Somogyi B, Nyitrai M
JournalFEBS Lett
PubMed ID15620683
'The stabilisation of magnesium actin filaments by phalloidin and jasplakinolide was studied using the method of differential scanning calorimetry. The results showed that actin could adapt three conformations in the presence of drugs. One conformation was adapted in direct interaction with the drug, while another conformation was identical to that ... 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
Chondramides A approximately D, new antifungal and cytostatic depsipeptides from Chondromyces crocatus (myxobacteria). Production, physico-chemical and biological properties.
AuthorsKunze B, Jansen R, Sasse F, Höfle G, Reichenbach H
JournalJ Antibiot (Tokyo)
PubMed ID8557566
'Novel depsipeptides, named chondramides were produced at levels up to 4.3 mg/liter by several myxobacteria of the genus Chondromyces. The compounds are structurally closely related to jaspamide/jasplakinolide from marine sponges of the genus Jaspis. Initially the chondramides were detected in acetone extracts of the biomass of Chondromyces crocatus, strain Cm ... More
The interaction of tropomodulin with tropomyosin stabilizes thin filaments in cardiac myocytes.
AuthorsMudry RE, Perry CN, Richards M, Fowler VM, Gregorio CC
JournalJ Cell Biol
PubMed ID12975349
'Actin (thin) filament length regulation and stability are essential for striated muscle function. To determine the role of the actin filament pointed end capping protein, tropomodulin1 (Tmod1), with tropomyosin, we generated monoclonal antibodies (mAb17 and mAb8) against Tmod1 that specifically disrupted its interaction with tropomyosin in vitro. Microinjection of mAb17 ... More
Single-molecule speckle analysis of actin filament turnover in lamellipodia.
AuthorsWatanabe N, Mitchison TJ
JournalScience
PubMed ID11834838
'Lamellipodia are thin, veil-like extensions at the edge of cells that contain a dynamic array of actin filaments. We describe an approach for analyzing spatial regulation of actin polymerization and depolymerization in vivo in which we tracked single molecules of actin fused to the green fluorescent protein. Polymerization and the ... More
A role for actin dynamics in individualization during spermatogenesis in Drosophila melanogaster.
AuthorsNoguchi T, Miller KG
JournalDevelopment
PubMed ID12642486
'In order to better understand the mechanism of sperm individualization during spermatogenesis in Drosophila melanogaster, we have developed an in vitro culture system in which we can perform live observation of individualization in isolated cysts. The whole process of individualization, during which a bundle of 64 syncytial spermatids is separated ... More
Phospholipids undergo hop diffusion in compartmentalized cell membrane.
AuthorsFujiwara T, Ritchie K, Murakoshi H, Jacobson K, Kusumi A
JournalJ Cell Biol
PubMed ID12058021
'The diffusion rate of lipids in the cell membrane is reduced by a factor of 5-100 from that in artificial bilayers. This slowing mechanism has puzzled cell biologists for the last 25 yr. Here we address this issue by studying the movement of unsaturated phospholipids in rat kidney fibroblasts at ... 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
Alterations of the actin polymerization status as an apoptotic morphological effector in HL-60 cells.
AuthorsRao JY, Jin YS, Zheng Q, Cheng J, Tai J, Hemstreet GP
JournalJ Cell Biochem
PubMed ID10572251
'The alterations of the cytoskeletal actin network have been implicated as a morphological effector in apoptosis. However, studies directly linking actin change to the morphological events in apoptosis are lacking. This study quantitatively examined the effect of actin alteration on the camptothecin (CPT)-induced apoptotic process in HL-60 cells. Actin alteration ... 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
Biomolecular mimicry in the actin cytoskeleton: mechanisms underlying the cytotoxicity of kabiramide C and related macrolides.
AuthorsTanaka J, Yan Y, Choi J, Bai J, Klenchin VA, Rayment I, Marriott G
JournalProc Natl Acad Sci U S A
PubMed ID14612571
'This study characterizes the interactions between kabiramide C (KabC) and related macrolides and actin and establishes the mechanisms that underlie their inhibition of actin filament dynamics and cytotoxicity. The G-actin-KabC complex is formed through a two-step binding reaction and is extremely stable and long-lived. Competition-binding studies show that KabC binds ... More
Actin has a molecular scaffolding, not propulsive, role in presynaptic function.
AuthorsSankaranarayanan S, Atluri PP, Ryan TA
JournalNat Neurosci
PubMed ID12536209
'We used actin tagged with enhanced green fluorescent protein (EGFP-actin) to characterize the distribution and dynamics of actin in living presynaptic terminals in rat CNS neurons. Actin was preferentially concentrated around--and appeared to surround--the presynaptic vesicle cluster. In resting terminals, approximately 30% of actin was found to be in a ... More
Cytokinesis in eukaryotes.
AuthorsGuertin DA, Trautmann S, McCollum D
JournalMicrobiol Mol Biol Rev
PubMed ID12040122
'Cytokinesis is the final event of the cell division cycle, and its completion results in irreversible partition of a mother cell into two daughter cells. Cytokinesis was one of the first cell cycle events observed by simple cell biological techniques; however, molecular characterization of cytokinesis has been slowed by its ... More
Cadherin function probed by laser tweezer and single molecule fluorescence in vascular endothelial cells.
AuthorsBaumgartner W, Schütz GJ, Wiegand J, Golenhofen N, Drenckhahn D
JournalJ Cell Sci
PubMed ID12584244
'In endothelial monolayers agonist-induced influx of Ca(2+) and activities of the actin cytoskeleton have been shown to be crucially involved in regulation of barrier properties. By laser tweezer application we demonstrated that the strength of adhesion of VE-cadherin-coated microspheres to the surface of cultured endothelial monolayers is significantly reduced by ... More
LIMK1 regulates Golgi dynamics, traffic of Golgi-derived vesicles, and process extension in primary cultured neurons.
AuthorsRosso S, Bollati F, Bisbal M, Peretti D, Sumi T, Nakamura T, Quiroga S, Ferreira A, Cáceres A
JournalMol Biol Cell
PubMed ID15090620
'In this study, we examined the subcellular distribution and functions of LIMK1 in developing neurons. Confocal microscopy, subcellular fractionation, and expression of several epitope-tagged LIMK1 constructs revealed that LIMK1 is enriched in the Golgi apparatus and growth cones, with the LIM domain required for Golgi localization and the PDZ domain ... More
Myosin A tail domain interacting protein (MTIP) localizes to the inner membrane complex of Plasmodium sporozoites.
AuthorsBergman LW, Kaiser K, Fujioka H, Coppens I, Daly TM, Fox S, Matuschewski K, Nussenzweig V, Kappe SH
JournalJ Cell Sci
PubMed ID12456714
'Apicomplexan host cell invasion and gliding motility depend on the parasite''s actomyosin system located beneath the plasma membrane of invasive stages. Myosin A (MyoA), a class XIV unconventional myosin, is the motor protein. A model has been proposed to explain how the actomyosin motor operates but little is known about ... More
PKC-epsilon regulates basolateral endocytosis in human T84 intestinal epithelia: role of F-actin and MARCKS.
'Protein kinase C (PKC) and the actin cytoskeleton are critical effectors of membrane trafficking in mammalian cells. In polarized epithelia, the role of these factors in endocytic events at either the apical or basolateral membrane is poorly defined. In the present study, phorbol 12-myristate 13-acetate (PMA) and other activators 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
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
Glucose regulates the cortical actin network through modulation of Cdc42 cycling to stimulate insulin secretion.
AuthorsNevins AK, Thurmond DC
JournalAm J Physiol Cell Physiol
PubMed ID12760905
'Glucose-stimulated insulin granule exocytosis in pancreatic beta-cells involves cortical actin remodeling that results in the transient disruption of the interaction between polymerized actin with the plasma membrane t-SNARE (target membrane soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex. To examine the mechanism underlying the initiation of cortical actin remodeling, we have ... More
Emerging themes in lipid rafts and caveolae.
AuthorsGalbiati F, Razani B, Lisanti MP
JournalCell
PubMed ID11525727
Jasplakinolide. An actin-specific reagent that promotes actin polymerization.
AuthorsHolzinger A
JournalMethods Mol Biol
PubMed ID11190499
Molecular links between endocytosis and the actin cytoskeleton.
AuthorsQualmann B, Kessels MM, Kelly RB
JournalJ Cell Biol
PubMed ID10974009
A further study of the cytotoxic constituents of a milnamide-producing sponge.
AuthorsSonnenschein RN, Farias JJ, Tenney K, Mooberry SL, Lobkovsky E, Clardy J, Crews P
JournalOrg Lett
PubMed ID14986973
A reinvestigation of Auletta sp. yielded the novel compound milnamide C (3) plus the known compounds milnamide A (1), milnamide B (hemiasterlin) (2), jasplakinolide (5), and geodiamolides A (6), D (7), E (8), and G (9). The isolation work was guided by cytoskeletal bioactivity data. Compounds 2 and 3 were ... More
Vam10p defines a Sec18p-independent step of priming that allows yeast vacuole tethering.
AuthorsKato M, Wickner W
JournalProc Natl Acad Sci U S A
PubMed ID12748377
YOR068c, termed VAM10 (altered vacuole morphology), lies within the VPS5 gene on the opposite DNA strand. VAM10 deletion causes vacuole fragmentation in vivo. The in vitro fusion of purified yeast vacuoles is stimulated by recombinant Vam10p and blocked by antibody to Vam10p. Vam10p acts early in the priming stage of ... More