scholarly journals Cortactin is necessary for E-cadherin–mediated contact formation and actin reorganization

2004 ◽  
Vol 164 (6) ◽  
pp. 899-910 ◽  
Author(s):  
Falak M. Helwani ◽  
Eva M. Kovacs ◽  
Andrew D. Paterson ◽  
Suzie Verma ◽  
Radiya G. Ali ◽  
...  
Keyword(s):  
Contact Zone ◽  
Adhesive Contact ◽  
Actin Dynamics ◽  
Contact Formation ◽  
Biochemical Interaction ◽  
Embryonic Life ◽  
Generating Capacity ◽  
Mediated Contact ◽  
Adhesive Contacts ◽  
Cell Cell

Classical cadherin adhesion molecules are key determinants of cell–cell recognition during development and in post-embryonic life. A decisive step in productive cadherin-based recognition is the conversion of nascent adhesions into stable zones of contact. It is increasingly clear that such contact zone extension entails active cooperation between cadherin adhesion and the force-generating capacity of the actin cytoskeleton. Cortactin has recently emerged as an important regulator of actin dynamics in several forms of cell motility. We now report that cortactin is recruited to cell–cell adhesive contacts in response to homophilic cadherin ligation. Notably, cortactin accumulates preferentially, with Arp2/3, at cell margins where adhesive contacts are being extended. Recruitment of cortactin is accompanied by a ligation-dependent biochemical interaction between cortactin and the cadherin adhesive complex. Inhibition of cortactin activity in cells blocked Arp2/3-dependent actin assembly at cadherin adhesive contacts, significantly reduced cadherin adhesive contact zone extension, and perturbed both cell morphology and junctional accumulation of cadherins in polarized epithelia. Together, our findings identify a necessary role for cortactin in the cadherin–actin cooperation that supports productive contact formation.

scholarly journals Regulation of myosin activation during cell–cell contact formation by Par3-Lgl antagonism: entosis without matrix detachment

2012 ◽  
Vol 23 (11) ◽  
pp. 2076-2091 ◽  
Author(s):  
Qingwen Wan ◽  
Jing Liu ◽  
Zhen Zheng ◽  
Huabin Zhu ◽  
Xiaogang Chu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Myosin Ii ◽  
Coiled Coil ◽  
Host Cells ◽  
Cell Contact ◽  
Contact Formation ◽  
Cell Internalization ◽  
Mammary Gland Epithelial Cells ◽  
Cell Cell

Cell–cell contact formation following cadherin engagement requires actomyosin contraction along the periphery of cell–cell contact. The molecular mechanisms that regulate myosin activation during this process are not clear. In this paper, we show that two polarity proteins, partitioning defective 3 homologue (Par3) and mammalian homologues of Drosophila Lethal (2) Giant Larvae (Lgl1/2), antagonize each other in modulating myosin II activation during cell–cell contact formation in Madin-Darby canine kidney cells. While overexpression of Lgl1/2 or depletion of endogenous Par3 leads to enhanced myosin II activation, knockdown of Lgl1/2 does the opposite. Intriguingly, altering the counteraction between Par3 and Lgl1/2 induces cell–cell internalization during early cell–cell contact formation, which involves active invasion of the lateral cell–cell contact underneath the apical-junctional complexes and requires activation of the Rho–Rho-associated, coiled-coil containing protein kinase (ROCK)–myosin pathway. This is followed by predominantly nonapoptotic cell-in-cell death of the internalized cells and frequent aneuploidy of the host cells. Such effects are reminiscent of entosis, a recently described process observed when mammary gland epithelial cells were cultured in suspension. We propose that entosis could occur without matrix detachment and that overactivation of myosin or unbalanced myosin activation between contacting cells may be the driving force for entosis in epithelial cells.

Transitions of Shear Resistance in a Single-Asperity Contact

1998 ◽  
Vol 539 ◽  
Author(s):  
J. A. Hurtado ◽  
K.-S. Kim
Keyword(s):  
Contact Zone ◽  
Shear Force ◽  
Friction Stress ◽  
Adhesive Contact ◽  
Nanometer Scale ◽  
Asperity Contact ◽  
Normal Loading ◽  
Single Asperity ◽  
Single Asperity Contact ◽  
Contact Size

AbstractThe shear force required to emit circular dislocation loops from the edge of a circular adhesive-contact zone is calculated analytically as a function of contact-zone radii. The emission condition is based on the balance of the configurational force and the Peierls force on a dislocation loop initiated at the edge of the adhesive contact zone. The analysis suggests that there is a transition, for a nanometer-scale single-asperity contact, from concurrent (mobile- dislocation-free) slip to single-dislocation-assisted (SDA) slip. The nanometer-scale friction stress (shear force required for slip/contact area), which experimentally is observed independent of normal loading and contact-zone size, is believed to be the stress required for concurrent slip. The analysis also predicts a second transition from SDA slip to multiple-dislocation-cooperated (MDC) slip at the scale of tens of micrometers in contact size. The friction stress at this large length scale has also been observed experimentally to be independent of normal loading and contact size; however, the friction stress at the nanometer scale is about 30 times that at the scale of tens of micrometers. The analysis is consistent with these experimental observations.

Rho-family small GTPases are involved in forskolin-induced cell-cell contact formation of renal glomerular podocytes in vitro

2007 ◽  
Vol 328 (2) ◽  
pp. 391-400 ◽  
Author(s):  
Shuang-yan Gao ◽  
Chun-yu Li ◽  
Tetsuya Shimokawa ◽  
Takehiro Terashita ◽  
Seiji Matsuda ◽  
...  
Keyword(s):  
Small Gtpases ◽  
Cell Contact ◽  
Contact Formation ◽  
Rho Family ◽  
Cell Cell

Adhesive Contacts for Graded-Elastic Coatings Using Fourier Series Decomposition

2011 ◽  
Author(s):  
S. J. Chidlow ◽  
W. W. F. Chong ◽  
M. Teodorescu ◽  
N. D. Vaughan
Keyword(s):  
Fourier Series ◽  
Analytic Solution ◽  
Adhesive Contact ◽  
Solution Technique ◽  
Control Case ◽  
Principal Stresses ◽  
Pressure Distributions ◽  
Surface Deflection ◽  
Elastic Layers ◽  
Adhesive Contacts

We propose a semi-analytic solution technique to determine the subsurface stresses and local deflections resulting in an adhesive contact of graded elastic layers. Identical pressure distributions, typical for a Maugis parameter λ = 1, were applied to a range of graded elastic coatings. The principal stresses and surface deflection in both regions (graded elastic layer and substrate) are computed in terms of Fourier series. This control case has the advantage that the response of different coatings can be easily monitored and compared.

scholarly journals Role of Fat1 in cell-cell contact formation of podocytes in puromycin aminonucleoside nephrosis and neonatal kidney

2005 ◽  
Vol 68 (2) ◽  
pp. 542-551 ◽  
Author(s):  
Eishin Yaoita ◽  
Hidetake Kurihara ◽  
Yutaka Yoshida ◽  
Tsutomu Inoue ◽  
Asako Matsuki ◽  
...  
Keyword(s):  
Cell Contact ◽  
Puromycin Aminonucleoside ◽  
Contact Formation ◽  
Neonatal Kidney ◽  
Aminonucleoside Nephrosis ◽  
Puromycin Aminonucleoside Nephrosis ◽  
Cell Cell

scholarly journals WT1-interacting protein (Wtip) regulates podocyte phenotype by cell-cell and cell-matrix contact reorganization

2012 ◽  
Vol 302 (1) ◽  
pp. F103-F115 ◽  
Author(s):  
Jane H. Kim ◽  
Amitava Mukherjee ◽  
Sethu M. Madhavan ◽  
Martha Konieczkowski ◽  
John R. Sedor
Keyword(s):  
Kinase Inhibitor ◽  
Adherens Junctions ◽  
Focal Adhesions ◽  
Stress Fibers ◽  
Actin Dynamics ◽  
Transcriptional Responses ◽  
Interacting Protein ◽  
Cell Matrix ◽  
Actin Stress Fibers ◽  
Cell Cell

Podocytes respond to environmental cues by remodeling their slit diaphragms and cell-matrix adhesive junctions. Wt1-interacting protein (Wtip), an Ajuba family LIM domain scaffold protein expressed in the podocyte, coordinates cell adhesion changes and transcriptional responses to regulate podocyte phenotypic plasticity. We evaluated effects of Wtip on podocyte cell-cell and cell-matrix contact organization using gain-of- and loss-of-function methods. Endogenous Wtip targeted to focal adhesions in adherent but isolated podocytes and then shifted to adherens junctions after cells made stable, homotypic contacts. Podocytes with Wtip knockdown (shWtip) adhered but failed to spread normally. Noncontacted shWtip podocytes did not assemble actin stress fibers, and their focal adhesions failed to mature. As shWtip podocytes established cell-cell contacts, stable adherens junctions failed to form and F-actin structures were disordered. In shWtip cells, cadherin and β-catenin clustered in irregularly distributed spots that failed to laterally expand. Cell surface biotinylation showed diminished plasma membrane cadherin, β-catenin, and α-catenin in shWtip podocytes, although protein expression was similar in shWtip and control cells. Since normal actin dynamics are required for organization of adherens junctions and focal adhesions, we determined whether Wtip regulates F-actin assembly. Undifferentiated podocytes did not elaborate F-actin stress fibers, but when induced to overexpress WTIP, formed abundant stress fibers, a process blocked by the RhoA inhibitor C3 toxin and a RhoA kinase inhibitor. WTIP directly interacted with Rho guanine nucleotide exchange factor (GEF) 12 (Arhgef12), a RhoA-specific GEF enriched in the glomerulus. In conclusion, stable assembly of podocyte adherens junctions and cell-matrix contacts requires Wtip, a process that may be mediated by spatiotemporal regulation of RhoA activity through appropriate targeting of Arhgef12.

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