Control of integrin alphaIIb beta3 outside-in signaling and platelet adhesion by sensing the physical properties of fibrin(ogen) substrates.
AuthorsPodolnikova NP, Yermolenko IS, Fuhrmann A, Lishko VK, Magonov S, Bowen B, Enderlein J, Podolnikov AV, Ros R, Ugarova TP,
JournalBiochemistry
PubMed ID19929007
The physical properties of substrates are known to control cell adhesion via integrin-mediated signaling. Fibrin and fibrinogen, the principal components of hemostatic and pathological thrombi, may represent biologically relevant substrates whose variable physical properties control adhesion of leukocytes and platelets. In our previous work, we have shown that binding of ... More
Phosphocaveolin-1 is a mechanotransducer that induces caveola biogenesis via Egr1 transcriptional regulation.
AuthorsJoshi B, Bastiani M, Strugnell SS, Boscher C, Parton RG, Nabi IR,
JournalJ Cell Biol
PubMed ID23091071
'Caveolin-1 (Cav1) is an essential component of caveolae whose Src kinase-dependent phosphorylation on tyrosine 14 (Y14) is associated with regulation of focal adhesion dynamics. However, the relationship between these disparate functions remains to be elucidated. Caveola biogenesis requires expression of both Cav1 and cavin-1, but Cav1Y14 phosphorylation is dispensable. In ... More
Micron-scale spatially patterned, covalently immobilized vascular endothelial growth factor on hydrogels accelerates endothelial tubulogenesis and increases cellular angiogenic responses.
AuthorsLeslie-Barbick JE, Shen C, Chen C, West JL,
JournalTissue Eng Part A
PubMed ID20712418
'Spontaneous formation of endothelial tubules was restricted to patterned micron-scale regions presenting cell adhesion ligands and angiogenic signaling protein on poly(ethylene glycol) hydrogels. Arginine-glycine-aspartic acid-serine (RGDS), an integrin ligand, and vascular endothelial growth factor (VEGF), a rate-limiting signaling protein involved in angiogenesis, were covalently bound through photopolymerization via laser scanning ... More
Phosphorylation of spinophilin by ERK and cyclin-dependent PK 5 (Cdk5).
AuthorsFutter M, Uematsu K, Bullock SA, Kim Y, Hemmings HC, Nishi A, Greengard P, Nairn AC
JournalProc Natl Acad Sci U S A
PubMed ID15728359
'Spinophilin is a protein that binds to protein phosphatase-1 and actin and modulates excitatory synaptic transmission and dendritic spine morphology. We have identified three sites phosphorylated by ERK2 (Ser-15 and Ser-205) and cyclin-dependent PK 5 (Cdk5) (Ser-17), within the actin-binding domain of spinophilin. Cdk5 and ERK2 both phosphorylated spinophilin in ... More
A high-throughput, cell-based screening method for siRNA and small molecule inhibitors of mTORC1 signaling using the In Cell Western technique.
AuthorsHoffman GR, Moerke NJ, Hsia M, Shamu CE, Blenis J,
JournalAssay Drug Dev Technol
PubMed ID20085456
'The mTORC1 pathway is a central regulator of cell growth, and defective mTORC1 regulation plays a causative role in a variety of human diseases, including cancer, tumor syndromes such as the tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM), and metabolic diseases such as diabetes and obesity. Given the importance of ... More
Restriction of secretory granule motion near the plasma membrane of chromaffin cells.
AuthorsJohns LM, Levitan ES, Shelden EA, Holz RW, Axelrod D
JournalJ Cell Biol
PubMed ID11285284
'We used total internal reflection fluorescence microscopy to study quantitatively the motion and distribution of secretory granules near the plasma membrane (PM) of living bovine chromaffin cells. Within the approximately 300-nm region measurably illuminated by the evanescent field resulting from total internal reflection, granules are preferentially concentrated close to the ... More
Different splice variants of filamin-B affect myogenesis, subcellular distribution, and determine binding to integrin [beta] subunits.
Authorsvan der Flier A, Kuikman I, Kramer D, Geerts D, Kreft M, Takafuta T, Shapiro SS, Sonnenberg A
JournalJ Cell Biol
PubMed ID11807098
'Integrins connect the extracellular matrix with the cell interior, and transduce signals through interactions of their cytoplasmic tails with cytoskeletal and signaling proteins. Using the yeast two-hybrid system, we isolated a novel splice variant (filamin-Bvar-1) of the filamentous actin cross-linking protein, filamin-B, that interacts with the cytoplasmic domain of the ... More
Galpha11 induces caspase-mediated proteolytic activation of Rho-associated kinase, ROCK-I, in HeLa cells.
'Expression of the constitutively active mutant of Galpha(11) (Galpha(11)QL) induces the formation of vinculin-containing focal adhesion-like structures in HeLa cells. This was found to be inhibited by Y-27632, a specific inhibitor of Rho-associated kinases (ROCK), but not by co-expression with a dominant negative mutant of RhoA, suggesting Rho-independent activation of ... More
Focal adhesion size controls tension-dependent recruitment of alpha-smooth muscle actin to stress fibers.
AuthorsGoffin JM, Pittet P, Csucs G, Lussi JW, Meister JJ, Hinz B
JournalJ Cell Biol
PubMed ID16401722
'Expression of alpha-smooth muscle actin (alpha-SMA) renders fibroblasts highly contractile and hallmarks myofibroblast differentiation. We identify alpha-SMA as a mechanosensitive protein that is recruited to stress fibers under high tension. Generation of this threshold tension requires the anchoring of stress fibers at sites of 8-30-microm-long "supermature" focal adhesions (suFAs), which ... More
Wiskott-Aldrich syndrome protein is a key regulator of the phagocytic cup formation in macrophages.
AuthorsTsuboi S, Meerloo J,
JournalJ Biol Chem
PubMed ID17890224
'Phagocytosis is a vital first-line host defense mechanism against infection involving the ingestion and digestion of foreign materials such as bacteria by specialized cells, phagocytes. For phagocytes to ingest the foreign materials, they form an actin-based membrane structure called phagocytic cup at the plasma membranes. Formation of the phagocytic cup ... More
Cytoplasmic gamma-actin contributes to a compensatory remodeling response in dystrophin-deficient muscle.
AuthorsHanft LM, Rybakova IN, Patel JR, Rafael-Fortney JA, Ervasti JM
JournalProc Natl Acad Sci U S A
PubMed ID16565216
'Dystrophin mechanically links the costameric cytoskeleton and sarcolemma, yet dystrophin-deficient muscle exhibits abnormalities in cell signaling, gene expression, and contractile function that are not clearly understood. We generated new antibodies specific for cytoplasmic gamma-actin and confirmed that gamma-actin most predominantly localized to the sarcolemma and in a faint reticular lattice ... More
Actin depolymerization transduces the strength of B-cell receptor stimulation.
AuthorsHao S, August A
JournalMol Biol Cell
PubMed ID15728723
'Polymerization of the actin cytoskeleton has been found to be essential for B-cell activation. We show here, however, that stimulation of BCR induces a rapid global actin depolymerization in a BCR signal strength-dependent manner, followed by polarized actin repolymerization. Depolymerization of actin enhances and blocking actin depolymerization inhibits BCR signaling, ... More
Transmission of growth cone traction force through apCAM-cytoskeletal linkages is regulated by Src family tyrosine kinase activity.
AuthorsSuter DM, Forscher P
JournalJ Cell Biol
PubMed ID11673478
'Tyrosine kinase activity is known to be important in neuronal growth cone guidance. However, underlying cellular mechanisms are largely unclear. Here, we report how Src family tyrosine kinase activity controls apCAM-mediated growth cone steering by regulating the transmission of traction forces through receptor-cytoskeletal linkages. Increased levels of tyrosine phosphorylation were ... More
Mutation of the atrophin2 gene in the zebrafish disrupts signaling by fibroblast growth factor during development of the inner ear.
AuthorsAsai Y, Chan DK, Starr CJ, Kappler JA, Kollmar R, Hudspeth AJ
JournalProc Natl Acad Sci U S A
PubMed ID16754885
'The development of the vertebrate inner ear depends on the precise expression of fibroblast growth factors. In a mutagenesis screen for zebrafish with abnormalities of inner-ear development and behavior, we isolated a mutant line, ru622, whose phenotypic characteristics resembled those of null mutants for the gene encoding fibroblast growth factor ... 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
Changes in the balance between caldesmon regulated by p21-activated kinases and the Arp2/3 complex govern podosome formation.
AuthorsMorita T, Mayanagi T, Yoshio T, Sobue K
JournalJ Biol Chem
PubMed ID17224451
'Podosomes are dynamic cell adhesion structures that degrade the extracellular matrix, permitting extracellular matrix remodeling. Accumulating evidence suggests that actin and its associated proteins play a crucial role in podosome dynamics. Caldesmon is localized to the podosomes, and its expression is down-regulated in transformed and cancer cells. Here we studied ... More
Multiphoton excitation spectra in biological samples.
AuthorsDickinson ME, Simbuerger E, Zimmermann B, Waters CW, Fraser SE
JournalJ Biomed Opt
PubMed ID12880336
'Multiphoton microscopy is becoming a popular mode of live and fixed cell imaging. This mode of imaging offers several advantages due to the fact that fluorochrome excitation is a nonlinear event resulting in excitation only at the plane of focus. Multiphoton excitation is enhanced by the use of ultrafast lasers ... More
Identification of ARAP3, a novel PI3K effector regulating both Arf and Rho GTPases, by selective capture on phosphoinositide affinity matrices.
AuthorsKrugmann S, Anderson KE, Ridley SH, Risso N, McGregor A, Coadwell J, Davidson K, Eguinoa A, Ellson CD, Lipp P, Manifava M, Ktistakis N, Painter G, Thuring JW, Cooper MA, Lim ZY, Holmes AB, Dove SK, Michell RH, Grewal A, Nazarian A, Erdjument-Bromage H, Tempst P, Stephens LR, Hawkins PT
JournalMol Cell
PubMed ID11804589
'We show that matrices carrying the tethered homologs of natural phosphoinositides can be used to capture and display multiple phosphoinositide binding proteins in cell and tissue extracts. We present the mass spectrometric identification of over 20 proteins isolated by this method, mostly from leukocyte extracts: they include known and novel ... More
Relocalization of junctional adhesion molecule A during inflammatory stimulation of brain endothelial cells.
AuthorsStamatovic SM, Sladojevic N, Keep RF, Andjelkovic AV,
JournalMol Cell Biol
PubMed ID22733993
'Junctional adhesion molecule A (JAM-A) is a unique tight junction (TJ) transmembrane protein that under basal conditions maintains endothelial cell-cell interactions but under inflammatory conditions acts as a leukocyte adhesion molecule. This study investigates the fate of JAM-A during inflammatory TJ complex remodeling and paracellular route formation in brain endothelial ... More
Model organisms: new insights into ion channel and transporter function. L-type calcium channels regulate epithelial fluid transport in Drosophila melanogaster.
'The neuropeptide CAP2b stimulates fluid transport obligatorily via calcium entry, nitric oxide, and cGMP in Drosophila melanogaster Malpighian (renal) tubules. We have shown by RT-PCR that the Drosophila L-type calcium channel alpha1-subunit genes Dmca1D and Dmca1A (nbA) are both expressed in tubules. CAP2b-stimulated fluid transport and cytosolic calcium concentration ([Ca2+]i) ... More
Stress fibers are generated by two distinct actin assembly mechanisms in motile cells.
AuthorsHotulainen P, Lappalainen P
JournalJ Cell Biol
PubMed ID16651381
'Stress fibers play a central role in adhesion, motility, and morphogenesis of eukaryotic cells, but the mechanism of how these and other contractile actomyosin structures are generated is not known. By analyzing stress fiber assembly pathways using live cell microscopy, we revealed that these structures are generated by two distinct ... More
Missing-in-metastasis and IRSp53 deform PI(4,5)P2-rich membranes by an inverse BAR domain-like mechanism.
AuthorsMattila PK, Pykäläinen A, Saarikangas J, Paavilainen VO, Vihinen H, Jokitalo E, Lappalainen P
JournalJ Cell Biol
PubMed ID17371834
'The actin cytoskeleton plays a fundamental role in various motile and morphogenetic processes involving membrane dynamics. We show that actin-binding proteins MIM (missing-in-metastasis) and IRSp53 directly bind PI(4,5)P(2)-rich membranes and deform them into tubular structures. This activity resides in the N-terminal IRSp53/MIM domain (IMD) of these proteins, which is structurally ... More
Simvastatin suppresses LPS-induced Akt phosphorylation in the human monocyte cell line THP-1.
AuthorsPatel TR, Corbett SA
JournalJ Surg Res
PubMed ID14732356
'BACKGROUND: Activation of the small GTPase, Rac, requires post-translational modification by isoprenylation. Statins interfere with this process by blocking the synthesis of isoprenoid intermediates. The protein kinase Akt is a multifunctional regulator of cell behavior that has been linked to Rac activation. We have shown that lipopolysaccharide (LPS) stimulation leads ... More
Entry is a rate-limiting step for viral infection in a Drosophila melanogaster model of pathogenesis.
AuthorsCherry S, Perrimon N
JournalNat Immunol
PubMed ID14691479
'The identification of host factors that control susceptibility to infection has been hampered by a lack of amenable genetic systems. We established an in vivo model to determine the host factors that control pathogenesis and identified viral entry as a rate-limiting step for infection. We infected Drosophila melanogaster cells and ... More
Cytoskeletal events preceding polar body formation in activated Spisula eggs.
AuthorsPielak RM, Gaysinskaya VA, Cohen WD
JournalBiol Bull
PubMed ID14583524
The dendritic cell cytoskeleton is critical for the formation of the immunological synapse.
AuthorsAl-Alwan MM, Rowden G, Lee TD, West KA
JournalJ Immunol
PubMed ID11160183
The binding of a T cell to an APC results in T cell actin cytoskeletal rearrangement leading to the formation of an immunological synapse. The APC cytoskeleton has been thought to play a passive role in this process. In this study, we demonstrate that dendritic cells (DC), unlike other APC, ... More
Mammalian Fat1 cadherin regulates actin dynamics and cell-cell contact.
AuthorsTanoue T, Takeichi M
JournalJ Cell Biol
PubMed ID15148305
Fat cadherins form a distinct subfamily of the cadherin gene superfamily, and are featured by their unusually large extracellular domain. In this work, we investigated the function of a mammalian Fat cadherin. Fat1 was localized at filopodial tips, lamellipodial edges, and cell-cell boundaries, overlapping with dynamic actin structures. RNA interference-mediated ... More
T cell antigen receptor signaling and immunological synapse stability require myosin IIA.
AuthorsIlani T, Vasiliver-Shamis G, Vardhana S, Bretscher A, Dustin ML,
JournalNat Immunol
PubMed ID19349987
Immunological synapses are initiated by signaling in discrete T cell antigen receptor microclusters and are important for the differentiation and effector functions of T cells. Synapse formation involves the orchestrated movement of microclusters toward the center of the contact area with the antigen-presenting cell. Microcluster movement is associated with centripetal ... More
Drosophila Rho-associated kinase (Drok) links Frizzled-mediated planar cell polarity signaling to the actin cytoskeleton.
AuthorsWinter CG, Wang B, Ballew A, Royou A, Karess R, Axelrod JD, Luo L
JournalCell
PubMed ID11301004
Frizzled (Fz) and Dishevelled (Dsh) are components of an evolutionarily conserved signaling pathway that regulates planar cell polarity. How this signaling pathway directs asymmetric cytoskeletal reorganization and polarized cell morphology remains unknown. Here, we show that Drosophila Rho-associated kinase (Drok) works downstream of Fz/Dsh to mediate a branch of the ... More
Quantitative measurement of F-actin accumulation at the NK cell immunological synapse.
AuthorsBanerjee PP, Orange JS,
JournalJ Immunol Methods
PubMed ID20171970
NK cells are lymphocytes of the innate immune system that can kill target cells after activation signal-induced directional secretion of lytic granule contents. This process depends upon F-actin polymerization at the NK cell immunological synapse (NKIS), which is the dynamic organization of molecules at the interface between the NK cell ... More
Granule exocytosis is required for platelet spreading: differential sorting of a-granules expressing VAMP-7.
AuthorsPeters CG, Michelson AD, Flaumenhaft R,
JournalBlood
PubMed ID22589474
There has been recent controversy as to whether platelet a-granules represent a single granule population or are composed of different subpopulations that serve discrete functions. To address this question, we evaluated the localization of vesicle-associated membrane proteins (VAMPs) in spread platelets to determine whether platelets actively sort a specific subpopulation ... More
WASH and the Arp2/3 complex regulate endosome shape and trafficking.
AuthorsDuleh SN, Welch MD,
JournalCytoskeleton (Hoboken)
PubMed ID20175130
Activators of the Arp2/3 complex, termed nucleation-promoting factors (NPFs), are required for the proper spatial and temporal control of actin assembly in cells. Mammalian cells express several NPFs, each of which functions in a distinct cellular process, including WASP and N-WASP in phagocytosis and endocytosis, WAVE and JMY in cell ... 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
Plasma membrane domain organization regulates EGFR signaling in tumor cells.
AuthorsLajoie P, Partridge EA, Guay G, Goetz JG, Pawling J, Lagana A, Joshi B, Dennis JW, Nabi IR,
JournalJ Cell Biol
PubMed ID17938246
Macromolecular complexes exhibit reduced diffusion in biological membranes; however, the physiological consequences of this characteristic of plasma membrane domain organization remain elusive. We report that competition between the galectin lattice and oligomerized caveolin-1 microdomains for epidermal growth factor (EGF) receptor (EGFR) recruitment regulates EGFR signaling in tumor cells. In mammary ... More
Defining mechanisms of actin polymerization and depolymerization during dendritic spine morphogenesis.
Dendritic spines are small protrusions along dendrites where the postsynaptic components of most excitatory synapses reside in the mature brain. Morphological changes in these actin-rich structures are associated with learning and memory formation. Despite the pivotal role of the actin cytoskeleton in spine morphogenesis, little is known about the mechanisms ... More
Galectin binding to Mgat5-modified N-glycans regulates fibronectin matrix remodeling in tumor cells.
AuthorsLagana A, Goetz JG, Cheung P, Raz A, Dennis JW, Nabi IR,
JournalMol Cell Biol
PubMed ID16581792
Oncogenic signaling stimulates the dynamic remodeling of actin microfilaments and substrate adhesions, essential for cell spreading and motility. Transformation is associated with increased expression of beta1,6GlcNAc-branched N-glycans, products of Golgi beta1,6-acetylglucosaminyltransferase V (Mgat5) and the favored ligand for galectins. Herein we report that fibronectin fibrillogenesis and fibronectin-dependent cell spreading are ... 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
Dynamin-related protein 1 (Drp1)-mediated diastolic dysfunction in myocardial ischemia-reperfusion injury: therapeutic benefits of Drp1 inhibition to reduce mitochondrial fission.
AuthorsSharp WW, Fang YH, Han M, Zhang HJ, Hong Z, Banathy A, Morrow E, Ryan JJ, Archer SL,
Journal
PubMed ID24076965
Mitochondrial fission, regulated by dynamin-related protein-1 (Drp1), is a newly recognized determinant of mitochondrial function, but its contribution to left ventricular (LV) impairment following ischemia-reperfusion (IR) injury is unknown. We report that Drp1 activation during IR results in LV dysfunction and that Drp1 inhibition is beneficial. In both isolated neonatal ... More
An immunohistochemical method for the detection of proteins in the vertebrate lens.
AuthorsReed NA, Oh DJ, Czymmek KJ, Duncan MK
JournalJ Immunol Methods
PubMed ID11384685
Fluorescence immunohistochemistry has traditionally been difficult or impossible to perform on the vertebrate lens because of its extremely high protein content. Described here is a robust and rapid method for preparing and labeling vertebrate eyes for confocal microscopy. This technique has successfully been applied to localize proteins in the lens ... More
Tyrosine phosphorylation of VE-cadherin prevents binding of p120- and beta-catenin and maintains the cellular mesenchymal state.
AuthorsPotter MD, Barbero S, Cheresh DA
JournalJ Biol Chem
PubMed ID16027153
In several pathological conditions, epithelial cells demonstrate a breakdown of barrier function and acquire an invasive phenotype. Endothelial cells in particular are maintained in a mesenchymal state during the cell invasion phase of angiogenesis. We show here that tyrosine phosphorylation of the adherens junction protein VE-cadherin at two critical tyrosines, ... More
Huntingtin-HAP40 complex is a novel Rab5 effector that regulates early endosome motility and is up-regulated in Huntington's disease.
AuthorsPal A, Severin F, Lommer B, Shevchenko A, Zerial M
JournalJ Cell Biol
PubMed ID16476778
The molecular mechanisms underlying the targeting of Huntingtin (Htt) to endosomes and its multifaceted role in endocytosis are poorly understood. In this study, we have identified Htt-associated protein 40 (HAP40) as a novel effector of the small guanosine triphosphatase Rab5, a key regulator of endocytosis. HAP40 mediates the recruitment of ... More
UNC-87 is an actin-bundling protein.
AuthorsKranewitter WJ, Ylanne J, Gimona M
JournalJ Biol Chem
PubMed ID11096113
The Caenorhabditis elegans unc-87 gene product is essential for the maintenance of the nematode body wall muscle where it is found colocalized with actin in the I band. The molecular domain structure of the protein reveals similarity to the C-terminal repeat region of the smooth muscle actin-binding protein calponin. In ... More
Inositol 1,4,5-trisphosphate 3-kinase A associates with F-actin and dendritic spines via its N terminus.
AuthorsSchell MJ, Erneux C, Irvine RF
JournalJ Biol Chem
PubMed ID11468283
The consequences of the rapid 3-phosphorylation of inositol 1,4,5-trisphosphate (IP(3)) to produce inositol 1,3,4,5-tetrakisphosphate (IP(4)) via the action of IP(3) 3-kinases involve the control of calcium signals. Using green fluorescent protein constructs of full-length and truncated IP(3) 3-kinase isoform A expressed in HeLa cells, COS-7 cells, and primary neuronal cultures, ... More
Identification of target actin content and polymerization status as a mechanism of tumor resistance after cytolytic T lymphocyte pressure.
AuthorsAbouzahr S, Bismuth G, Gaudin C, Caroll O, Van Endert P, Jalil A, Dausset J, Vergnon I, Richon C, Kauffmann A, Galon J, Raposo G, Mami-Chouaib F, Chouaib S
JournalProc Natl Acad Sci U S A
PubMed ID16432193
To investigate tumor resistance to T cell lysis, a resistant variant was selected after specific cytolytic T lymphocytes (CTL) selection pressure. Although the resistant variant triggered perforin and granzyme B transcription in specific CTLs, as well as their degranulation, it exhibited a dramatic resistance to cytotoxic T cell killing. It ... More
Counting dendritic spines in brain tissue slices by image correlation spectroscopy analysis.
AuthorsWiseman PW, Capani F, Squier JA, Martone ME
JournalJ Microsc
PubMed ID11879432
Growth of new micrometre sized projections called dendritic spines in neurones has been linked to the encoding of long-term memories in vertebrates. Numerous studies have been carried out at both the light and electron microscopy level to quantify dendritic spine densities in brain tissue in laboratory animals. Currently, such efforts ... More
Interaction between pyrin and the apoptotic speck protein (ASC) modulates ASC-induced apoptosis.
AuthorsRichards N, Schaner P, Diaz A, Stuckey J, Shelden E, Wadhwa A, Gumucio DL
JournalJ Biol Chem
PubMed ID11498534
Patients with familial Mediterranean fever suffer sporadic inflammatory attacks characterized by fever and intense pain (in joints, abdomen, or chest). Pyrin, the product of the MEFV locus, is a cytosolic protein whose function is unknown. Using pyrin as a "bait" to probe a yeast two-hybrid library made from neutrophil cDNA, ... More
The Rac activator Tiam1 is required for (alpha)3(beta)1-mediated laminin-5 deposition, cell spreading, and cell migration.
AuthorsHamelers IH, Olivo C, Mertens AE, Pegtel DM, van der Kammen RA, Sonnenberg A, Collard JG
JournalJ Cell Biol
PubMed ID16330714
The Rho-like guanosine triphosphatase Rac1 regulates various signaling pathways, including integrin-mediated adhesion and migration of cells. However, the mechanisms by which integrins signal toward Rac are poorly understood. We show that the Rac-specific guanine nucleotide exchange factor Tiam1 (T-lymphoma invasion and metastasis 1) is required for the integrin-mediated laminin (LN)-5 ... More
Phalloidin-eosin followed by photo-oxidation: a novel method for localizing F-actin at the light and electron microscopic levels.
AuthorsCapani F, Deerinck TJ, Ellisman MH, Bushong E, Bobik M, Martone ME
JournalJ Histochem Cytochem
PubMed ID11668188
We describe a novel high-resolution method to detect F-actin at the light and electron microscopic levels through the use of the actin-binding protein phalloidin conjugated to the fluorophore eosin, followed by photo-oxidation of diaminobenzidine. This method possesses several key advantages over antibody-based labeling and structural methods. First, phalloidin binding to ... More
Cytoskeletal dynamics and cell signaling during planar polarity establishment in the Drosophila embryonic denticle.
AuthorsPrice MH, Roberts DM, McCartney BM, Jezuit E, Peifer M
JournalJ Cell Sci
PubMed ID16418222
Many epithelial cells are polarized along the plane of the epithelium, a property termed planar cell polarity. The Drosophila wing and eye imaginal discs are the premier models of this process. Many proteins required for polarity establishment and its translation into cytoskeletal polarity were identified from studies of those tissues. ... More
A mutant alphaII-spectrin designed to resist calpain and caspase cleavage questions the functional importance of this process in vivo.
AuthorsMeary F, Metral S, Ferreira C, Eladari D, Colin Y, Lecomte MC, Nicolas G
JournalJ Biol Chem
PubMed ID17374614
alpha- and beta-spectrins are components of molecular scaffolds located under the lipid bilayer and named membrane skeletons. Disruption of these scaffolds through mutations in spectrins demonstrated that they are involved in the membrane localization or the maintenance of proteins associated with them. The ubiquitous alphaII-spectrin chain bears in its central ... More
Two distinct distributions of F-actin are present in the hyphal apex of the oomycete Achlya bisexualis.
AuthorsYu YP, Jackson SL, Garrill A
JournalPlant Cell Physiol
PubMed ID15047875
We show that two distinct distributions of F-actin are present in the hyphal apex of the oomycete Achlya bisexualis, that have been chemically fixed with a combination of methylglyoxal and formaldehyde and stained with Alexa phalloidin. In approximately one half of the hyphae examined, an F-actin depleted zone within the ... More
SadA, a novel adhesion receptor in Dictyostelium.
AuthorsFey P, Stephens S, Titus MA, Chisholm RL
JournalJ Cell Biol
PubMed ID12499361
Little is known about cell-substrate adhesion and how motile and adhesive forces work together in moving cells. The ability to rapidly screen a large number of insertional mutants prompted us to perform a genetic screen in Dictyostelium to isolate adhesion-deficient mutants. The resulting substrate adhesion-deficient (sad) mutants grew in plastic ... More
Insights into the dynamic properties of keratin intermediate filaments in living epithelial cells.
The properties of keratin intermediate filaments (IFs) have been studied after transfection with green fluorescent protein (GFP)-tagged K18 and/or K8 (type I/II IF proteins). GFP-K8 and -K18 become incorporated into tonofibrils, which are comprised of bundles of keratin IFs. These tonofibrils exhibit a remarkably wide range of motile and dynamic ... More
Transglutaminase 5 cross-links loricrin, involucrin, and small proline-rich proteins in vitro.
AuthorsCandi E, Oddi S, Terrinoni A, Paradisi A, Ranalli M, Finazzi-Agró A, Melino G
JournalJ Biol Chem
PubMed ID11443109
Transglutaminases (TGases) are seven enzymes, cross-linking proteins by gamma-glutamil-epsilon-lysine bonds, four of which are expressed in the skin. A new member of the TGase family, TGase 5, has been identified recently, and in the present study we evaluated its role in keratinocyte differentiation in vitro. In addition to the previously ... More
Vascularized organoid engineered by modular assembly enables blood perfusion.
AuthorsMcGuigan AP, Sefton MV
JournalProc Natl Acad Sci U S A
PubMed ID16864785
Tissue engineering is one approach to address the donor-organ shortage, but to attain clinically significant viable cell densities in thick tissues, laboratory-constructed tissues must have an internal vascular supply. We have adopted a biomimetic approach and assembled microscale modular components, consisting of submillimeter-sized collagen gel rods seeded with endothelial cells ... More
Dual-targeting immunotherapy of lymphoma: potent cytotoxicity of anti-CD20/CD74 bispecific antibodies in mantle cell and other lymphomas.
We describe the use of novel bispecific hexavalent Abs (HexAbs) to enhance anticancer immunotherapy. Two bispecific HexAbs [IgG-(Fab)(4) constructed from veltuzumab (anti-CD20 IgG) and milatuzumab (anti-CD74 IgG)] show enhanced cytotoxicity in mantle cell lymphoma (MCL) and other lymphoma/leukemia cell lines, as well as patient tumor samples, without a crosslinking Ab, ... More
A requirement for cytoplasmic dynein and dynactin in intermediate filament network assembly and organization.
AuthorsHelfand BT, Mikami A, Vallee RB, Goldman RD
JournalJ Cell Biol
PubMed ID12034772
We present evidence that vimentin intermediate filament (IF) motility in vivo is associated with cytoplasmic dynein. Immunofluorescence reveals that subunits of dynein and dynactin are associated with all structural forms of vimentin in baby hamster kidney-21 cells. This relationship is also supported by the presence of numerous components of dynein ... More
Protein phosphatase-1 binding to scd5p is important for regulation of actin organization and endocytosis in yeast.
AuthorsChang JS, Henry K, Wolf BL, Geli M, Lemmon SK
JournalJ Biol Chem
PubMed ID12356757
SCD5, an essential gene, encodes a protein important for endocytosis and actin organization in yeast. Previous two-hybrid screens showed that Scd5p interacts with Glc7p, a yeast Ser/Thr-specific protein phosphatase-1 (PP1) that participates in a variety of cellular processes. PP1 substrate specificity in vivo is regulated by association with different regulatory ... More
Isolation, cloning, and characterization of a new mammalian coronin family member, coroninse, which is regulated within the protein kinase C signaling pathway.
In order to understand the regulatory role of protein kinase C (PKC) in secretory epithelia, it is necessary to identify and characterize specific downstream targets. We previously identified one such protein in studies of gastric parietal cells. This protein was referred to as pp66 because it migrated with an apparent ... More
Yeast cells lacking the mitochondrial gene encoding the ATP synthase subunit 6 exhibit a selective loss of complex IV and unusual mitochondrial morphology.
AuthorsRak M, Tetaud E, Godard F, Sagot I, Salin B, Duvezin-Caubet S, Slonimski PP, Rytka J, di Rago JP
JournalJ Biol Chem
PubMed ID17261589
Atp6p is an essential subunit of the ATP synthase proton translocating domain, which is encoded by the mitochondrial DNA (mtDNA) in yeast. We have replaced the coding sequence of Atp6p gene with the non-respiratory genetic marker ARG8m. Due to the presence of ARG8m, accumulation of rho-/rho0 petites issued from large ... More
NIPA1(SPG6), the basis for autosomal dominant form of hereditary spastic paraplegia, encodes a functional Mg2+ transporter.
AuthorsGoytain A, Hines RM, El-Husseini A, Quamme GA
JournalJ Biol Chem
PubMed ID17166836
Mutations in the NIPA1(SPG6) gene, named for "nonimprinted in Prader-Willi/Angelman" has been implicated in one form of autosomal dominant hereditary spastic paraplegia (HSP), a neurodegenerative disorder characterized by progressive lower limb spasticity and weakness. However, the function of NIPA1 is unknown. Here, we show that reduced magnesium concentration enhances expression ... More
Live dynamics of GFP-calponin: isoform-specific modulation of the actin cytoskeleton and autoregulation by C-terminal sequences.
AuthorsDanninger C, Gimona M
JournalJ Cell Sci
PubMed ID11034901
The calponin family of F-actin-, tropomyosin- and calmodulin-binding proteins currently comprises three genetic variants. Their functional roles implicated from in vitro studies include the regulation of actomyosin interactions in smooth muscle cells (h1 calponin), cytoskeletal organisation in non-muscle cells (h2 calponin) and the control of neurite outgrowth (acidic calponin). We ... More
The verprolin-like central (vc) region of Wiskott-Aldrich syndrome protein induces Arp2/3 complex-dependent actin nucleation.
AuthorsHüfner K, Higgs HN, Pollard TD, Jacobi C, Aepfelbacher M, Linder S
JournalJ Biol Chem
PubMed ID11459849
Wiskott-Aldrich Syndrome protein (WASp) and related proteins stimulate actin filament nucleation by Arp2/3 complex. The isolated C-terminal VCA domain of WASp (containing Verprolin-like, Central and Acidic regions) is constitutively active but autoinhibited in the full-length protein. This study compared the ability of parts of VCA fused to the C terminus ... More
Pathogenic mycobacteria disrupt the macrophage actin filament network.
AuthorsGuérin I, de Chastellier C
JournalInfect Immun
PubMed ID10768957
Phagosomes with pathogenic mycobacteria retain fusion and intermingling characteristics of early endosomes indefinitely. The time course of acquisition of newly endocytosed tracers becomes, however, atypical (lag instead of immediate acquisition) starting from day 1 postinfection (p.i.), thereby suggesting that additional factors affect this process. Disruption of the actin filament (F-actin) ... More
Phosphatidylinositol-4,5-bisphosphate: actin dynamics and the regulation of ATP-dependent and -independent secretion.
AuthorsBittner MA, Holz RW
JournalMol Pharmacol
PubMed ID15635040
It has long been believed that the cortical actin cytoskeleton plays an important role in regulating the secretion of hormones and neurotransmitters. In this study, we investigated the control of actin dynamics in primary neuroendocrine cells and determined the relationship of actin dynamics to various components of the secretory response. ... More
The lateral mobility of NHE3 on the apical membrane of renal epithelial OK cells is limited by the PDZ domain proteins NHERF1/2, but is dependent on an intact actin cytoskeleton as determined by FRAP.
AuthorsCha B, Kenworthy A, Murtazina R, Donowitz M
JournalJ Cell Sci
PubMed ID15226406
The epithelial brush border (BB) Na+/H+ exchanger, NHE3, plays a major role in transcellular Na+ absorption in the renal proximal tubule. NHE3 activity is rapidly regulated by neurohumoral substances and growth factors via changes in its amount on the BB by a process partially involving vesicle trafficking. The PDZ domain-containing ... More
Imaging remodeling of the actin cytoskeleton in vascular smooth muscle cells after mechanosensitive arteriolar constriction.
AuthorsFlavahan NA, Bailey SR, Flavahan WA, Mitra S, Flavahan S
JournalAm J Physiol Heart Circ Physiol
PubMed ID15388507
Experiments were performed to determine whether remodeling of the actin cytoskeleton contributes to arteriolar constriction. Mouse tail arterioles were mounted on cannulae in a myograph and superfused with buffer solution. The alpha1-adrenergic agonist phenylephrine (0.1-1 micromol/l) caused constriction that was unaffected by cytochalasin D (300 nmol/l) or latrunculin A (100 ... More
Novel localization of Rab3D in rat intestinal goblet cells and Brunner's gland acinar cells suggests a role in early Golgi trafficking.
AuthorsValentijn JA, van Weeren L, Ultee A, Koster AJ
JournalAm J Physiol Gastrointest Liver Physiol
PubMed ID17395899
Rab3D is a small GTP-binding protein that associates with secretory granules of endocrine and exocrine cells. The physiological role of Rab3D remains unclear. While it has initially been implicated in the control of regulated exocytosis, recent deletion-mutation studies have suggested that Rab3D is involved in the biogenesis of secretory granules. ... More
Regulation of microfilament reorganization and invasiveness of breast cancer cells by kinase dead p21-activated kinase-1.
AuthorsAdam L, Vadlamudi R, Mandal M, Chernoff J, Kumar R
JournalJ Biol Chem
PubMed ID10766836
Stimulation of growth factor signaling has been implicated in the development of invasive phenotype and p21-activated kinase (PAK1) activation in human breast epithelial cancer cells. To further explore the roles of PAK1 in the invasive behavior of breast cancer cells, in the present study we investigated the influence of inhibition ... More
Serotonin-reuptake inhibitors act centrally to cause bone loss in mice by counteracting a local anti-resorptive effect.
Authors
JournalNat Med
PubMed ID27595322
Susceptibility to tuberculosis is associated with variants in the ASAP1 gene encoding a regulator of dendritic cell migration.
Authors
JournalNat Genet
PubMed ID25774636
Phosphoinositide Interactions Position cGAS at the Plasma Membrane to Ensure Efficient Distinction between Self- and Viral DNA.
Authors
JournalCell
PubMed ID30827685
DNA synthesis is required for reprogramming mediated by stem cell fusion.
Authors
JournalCell
PubMed ID23415233
Carbon Nanotube-Hydrogel Composites Facilitate Neuronal Differentiation While Maintaining Homeostasis of Network Activity.
Authors
JournalAdv Mater
PubMed ID34453367
Microglia and macrophages promote corralling, wound compaction and recovery after spinal cord injury via Plexin-B2.
Authors
JournalNat Neurosci
PubMed ID32112058
Human alpha B-crystallin mutation causes oxido-reductive stress and protein aggregation cardiomyopathy in mice.
Authors
JournalCell
PubMed ID17693254
FMN2 Makes Perinuclear Actin to Protect Nuclei during Confined Migration and Promote Metastasis.
Authors
JournalCell
PubMed ID27839864
An early cell shape transition drives evolutionary expansion of the human forebrain.
Authors
JournalCell
PubMed ID33765444
Simultaneous binding of Guidance Cues NET1 and RGM blocks extracellular NEO1 signaling.
Authors
JournalCell
PubMed ID33740419
Optimizing two-photon multiple fluorophore imaging of the human trabecular meshwork.
AuthorsGonzalez JM, Ammar MJ, Ko MK, Tan JC
JournalMol Vis
PubMed ID27122962
Advances in two-photon (2P) deep tissue imaging provide powerful options for simultaneously viewing multiple fluorophores within tissues. We determined imaging parameters for optimally visualizing three fluorophores in the human trabecular meshwork (TM) to simultaneously detect broad-spectrum autofluorescence and multiple fluorophores through a limited number of emission filters. ... More
Cell shape information is transduced through tension-independent mechanisms.
AuthorsRon A, Azeloglu EU, Calizo RC, Hu M, Bhattacharya S, Chen Y, Jayaraman G, Lee S, Neves-Zaph SR, Li H, Gordon RE, He JC, Hone JC, Iyengar R
JournalNat Commun
PubMed ID29247198
The shape of a cell within tissues can represent the history of chemical and physical signals that it encounters, but can information from cell shape regulate cellular phenotype independently? Using optimal control theory to constrain reaction-diffusion schemes that are dependent on different surface-to-volume relationships, we find that information from cell ... More
Signals of the Neuropilin-1-MET Axis and Cues of Mechanical Force Exertion Converge to Elicit Inflammatory Activation in Coherent Endothelial Cells.
AuthorsRezaei M, Martins Cavaco AC, Seebach J, Niland S, Zimmermann J, Hanschmann EM, Hallmann R, Schillers H, Eble JA
JournalJ Immunol
PubMed ID30692210
The neuropilin-1 (NRP1)-MET signaling axis regulates the motility of individual endothelial cells (ECs). It is unknown how this signaling pathway affects the endothelial barrier in coherent ECs forming a tight monolayer. We hypothesized that it is involved both in modulation of the endothelial barrier and in EC activation. To investigate ... More
XMAP215 promotes microtubule-F-actin interactions to regulate growth cone microtubules during axon guidance in
AuthorsSlater PG, Cammarata GM, Samuelson AG, Magee A, Hu Y, Lowery LA
JournalJ Cell Sci
PubMed ID30890650
It has long been established that neuronal growth cone navigation depends on changes in microtubule (MT) and F-actin architecture downstream of guidance cues. However, the mechanisms by which MTs and F-actin are dually coordinated remain a fundamentally unresolved question. Here, we report that the well-characterized MT polymerase, XMAP215 (also known ... More
Shear stress-induced nuclear shrinkage through activation of Piezo1 channels in epithelial cells.
AuthorsJetta D, Gottlieb PA, Verma D, Sachs F, Hua SZ
JournalJ Cell Sci
PubMed ID31076516
The cell nucleus responds to mechanical cues with changes in size, morphology and motility. Previous work has shown that external forces couple to nuclei through the cytoskeleton network, but we show here that changes in nuclear shape can be driven solely by calcium levels. Fluid shear stress applied to MDCK ... More
The transcriptional repressor SNAI2 impairs neuroblastoma differentiation and inhibits response to retinoic acid therapy.
AuthorsVrenken KS, Vervoort BMT, van Ingen Schenau DS, Derks YHW, van Emst L, Grytsenko PG, Middelbeek JAJ, van Leeuwen FN
JournalBiochim Biophys Acta Mol Basis Dis
PubMed ID31862304
Neuroblastoma is the most common extracranial solid tumor in children and originates from poorly differentiated neural crest progenitors. High-risk neuroblastoma patients frequently present with metastatic disease at diagnosis. Despite intensive treatment, patients often develop refractory disease characterized by poorly differentiated, therapy resistant cells. Although adjuvant therapy using retinoic acid (RA)-induced ... More