scholarly journals Activity and Distribution of Paxillin, Focal Adhesion Kinase, and Cadherin Indicate Cooperative Roles during Zebrafish Morphogenesis

2003 ◽  
Vol 14 (8) ◽  
pp. 3065-3081 ◽  
Author(s):  
Bryan D. Crawford ◽  
Clarissa A. Henry ◽  
Todd A. Clason ◽  
Amanda L. Becker ◽  
Merrill B. Hille

We investigated the focal adhesion proteins paxillin and Fak, and the cell-cell adhesion protein cadherin in developing zebrafish (Danio rerio) embryos. Cadherins are expressed in presomitic mesoderm where they delineate cells. The initiation of somite formation coincides with an increase in the phosphorylation of Fak, and the accumulation of Fak, phosphorylated Fak, paxillin, and fibronectin at nascent somite boundaries. In the notochord, cadherins are expressed on cells during intercalation, and phosphorylated Fak accumulates in circumferential rings where the notochord cells contact laminin in the perichordal sheath. Subsequently, changes in the orientations of collagen fibers in the sheath suggest that Fak-mediated adhesion allows longitudinal expansion of the notochord, but not lateral expansion, resulting in notochord elongation. Novel observations showed that focal adhesion kinase and paxillin concentrate at sites of cell-cell adhesion in the epithelial enveloping layer and may associate with actin cytoskeleton at epithelial junctions containing cadherins. Fak is phosphorylated at these epithelial junctions but is not phosphorylated on Tyr397, implicating a noncanonical mechanism of regulation. These data suggest that Fak and paxillin may function in the integration of cadherin-based and integrin-based cell adhesion during the morphogenesis of the early zebrafish embryo.

2005 ◽  
Vol 289 (6) ◽  
pp. L999-L1010 ◽  
Author(s):  
Peter V. Usatyuk ◽  
Viswanathan Natarajan

Oxidants, generated by activated neutrophils, have been implicated in the pathophysiology of vascular disorders and lung injury; however, mechanisms of oxidant-mediated endothelial barrier dysfunction are unclear. Here, we have investigated the role of focal adhesion kinase (FAK) in regulating hydrogen peroxide (H2O2)-mediated tyrosine phosphorylation of intercellular adhesion proteins and barrier function in endothelium. Treatment of bovine pulmonary artery endothelial cells (BPAECs) with H2O2 increased tyrosine phosphorylation of FAK, paxillin, β-catenin, and vascular endothelial (VE)-cadherin and decreased transendothelial electrical resistance (TER), an index of cell-cell adhesion and/or cell-matrix adhesion. To study the role of FAK in H2O2-induced TER changes, BPAECs were transfected with vector or FAK wild-type or FAK-related non-kinase (FRNK) plasmids. Overexpression of FRNK reduced FAK expression and attenuated H2O2-mediated tyrosine phosphorylation of FAK, paxillin, β-catenin, and VE-cadherin and cell-cell adhesion. Additionally, FRNK prevented H2O2-induced distribution of FAK, paxillin, β-catenin, or VE-cadherin toward focal adhesions and cell-cell adhesions but not actin stress fiber formation. These results suggest that activation of FAK by H2O2 is an important event in oxidant-mediated VE barrier function regulated by cell-cell and cell-matrix contacts.


2002 ◽  
Vol 70 (7) ◽  
pp. 3804-3815 ◽  
Author(s):  
Giorgio Santoni ◽  
Roberta Lucciarini ◽  
Consuelo Amantini ◽  
Jordan Jacobelli ◽  
Elisabetta Spreghini ◽  
...  

ABSTRACT The signaling pathways triggered by adherence of Candida albicans to the host cells or extracellular matrix are poorly understood. We provide here evidence in C. albicans yeasts of a p105 focal adhesion kinase (Fak)-like protein (that we termed CaFak), antigenically related to the vertebrate p125Fak, and its involvement in integrin-like-mediated fungus adhesion to vitronectin (VN) and EA.hy 926 human endothelial cell line. Biochemical analysis with different anti-chicken Fak antibodies identified CaFak as a 105-kDa protein and immunofluorescence and cytofluorimetric analysis on permeabilized cells specifically stain C. albicans yeasts; moreover, confocal microscopy evidences CaFak as a cytosolic protein that colocalizes on the membrane with the integrin-like VN receptors upon yeast adhesion to VN. The protein tyrosine kinase (PTK) inhibitors genistein and herbimycin A strongly inhibited C. albicans yeast adhesion to VN and EA.hy 926 endothelial cells. Moreover, engagement of αvβ3 and αvβ5 integrin-like on C. albicans either by specific monoclonal antibodies or upon adhesion to VN or EA.hy 926 endothelial cells stimulates CaFak tyrosine phosphorylation that is blocked by PTK inhibitor. A role for CaFak in C. albicans yeast adhesion was also supported by the failure of VN to stimulate its tyrosine phosphorylation in a C. albicans mutant showing normal levels of CaFak and VNR-like integrins but displaying reduced adhesiveness to VN and EA.hy 926 endothelial cells. Our results suggest that C. albicans Fak-like protein is involved in the control of yeast cell adhesion to VN and endothelial cells.


2000 ◽  
Vol 275 (49) ◽  
pp. 38371-38377 ◽  
Author(s):  
Patricia Lebrun ◽  
Véronique Baron ◽  
Christof R. Hauck ◽  
David D. Schlaepfer ◽  
Emmanuel Van Obberghen

2008 ◽  
Vol 87 (6) ◽  
pp. 377-387 ◽  
Author(s):  
Joong-Won Lee ◽  
Hee-Jin Kwak ◽  
Je-Jung Lee ◽  
Yong-Nyun Kim ◽  
Jung Weon Lee ◽  
...  

1996 ◽  
Vol 109 (5) ◽  
pp. 1009-1016
Author(s):  
S. Funamoto ◽  
H. Ochiai

The gp64 protein of Polysphondylium pallidum has been shown to mediate EDTA-stable cell-cell adhesion. To explore the functional role of gp64, we made an antisense RNA expression construct designed to prevent the gene expression of gp64; the construct was introduced into P. pallidum cells and the transformants were characterised. The antisense RNA-expressing clone L3mc2 which had just been harvested at the growth phase tended to re-form in aggregates smaller in size than did the parental cells in either the presence or absence of 10 mM EDTA. In contrast, 6.5-hour starved L3mc2 cells remained considerably dissociated from each other after 5 minutes gyrating, although aggregation gradually increased by 50% during a further 55 minutes gyrating in the presence of 10 mM EDTA. Correspondingly, L3mc2 lacked specifically the cell-cell adhesion protein, gp64. We therefore conclude that the gp64 protein is involved in forming the EDTA-resistant cell-cell contact. In spite of the absence of gp64, L3mc2 exhibited normal developmental processes, a fact which demonstrates that another cell-cell adhesion system exists in the development of Polysphondylium. This is the first report in which an antisense RNA technique was successfully applied to Polysphondylium.


1997 ◽  
Vol 272 (40) ◽  
pp. 25319-25325 ◽  
Author(s):  
Michael D. Schaller ◽  
Terukatsu Sasaki

2010 ◽  
pp. n/a-n/a ◽  
Author(s):  
David W. Dumbauld ◽  
Heungsoo Shin ◽  
Nathan D. Gallant ◽  
Kristin E. Michael ◽  
Harish Radhakrishna ◽  
...  

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