V. Gastrointestinal peptide signaling through tyrosine phosphorylation of focal adhesion proteins

1998 ◽  
Vol 275 (2) ◽  
pp. G177-G182 ◽  
Author(s):  
Enrique Rozengurt
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Biological Effects ◽  
Second Messengers ◽  
Regulatory Peptides ◽  
Adaptor Proteins ◽  
Nonreceptor Tyrosine Kinase ◽  
Adhesion Proteins ◽  
Focal Adhesion Proteins

Gastrointestinal (GI) peptides (also referred to as neuropeptides or regulatory peptides), including the mammalian bombesin-like peptides gastrin and CCK, elicit the synthesis of classic second messengers (e.g., Ca2+, diacylglycerol, and cAMP) and the consequent stimulation of serine/threonine protein kinase cascades. An emerging theme in signal transduction is that these agonists also induce rapid and coordinate tyrosine phosphorylation of a set of focal adhesion proteins, including the nonreceptor tyrosine kinase p125fak and the adaptor proteins p130cas and paxillin. GI peptide-mediated induction of tyrosine phosphorylation of these focal adhesion proteins is critically dependent on the integrity of the actin cytoskeleton and on functional Rho. The purpose of this article is to review recent advances in unraveling this novel tyrosine kinase pathway(s), because it appears to play a fundamental role in the mediation of important biological effects induced by GI peptides, including cell migration and proliferation.

Tyrosine phosphorylation of pp125FAK and paxillin in aortic endothelial cells induced by mechanical strain

1996 ◽  
Vol 271 (2) ◽  
pp. C635-C649 ◽  
Author(s):  
Y. Yano ◽  
J. Geibel ◽  
B. E. Sumpio
Keyword(s):  
Endothelial Cells ◽  
Morphological Change ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Cyclic Strain ◽  
Aortic Endothelial Cells ◽  
Adhesion Proteins ◽  
Focal Adhesion Proteins ◽  
And Migration ◽  
Aortic Endothelial

The objective of this study was to determine whether focal adhesion proteins pp125FAK (focal adhesion kinase) and paxillin are phosphorylated on tyrosine and might play a role in the morphological change and cell migration induced by strain. Bovine aortic endothelial cells (EC) were subjected to 10% average strain at 60 cycles/min. Cyclic strain increased the tyrosine phosphorylation of pp125FAK at 30 min (3.4-fold) and 4 h (5.9-fold) and the tyrosine phosphorylation of paxillin at 4 h (2.0-fold). Confocal microscopy showed that, after 4-h exposure to strain, EC began to elongate and F-actin, pp125FAK, and paxillin aligned, although they randomly distributed in static condition. Tyrosine kinase inhibitor tyrphostin A25 (100 microM) inhibited not only the tyrosine phosphorylation of pp125FAK and paxillin but also the redistribution of pp125FAK and paxillin, morphological change, and migration of EC induced by strain. These data demonstrate that cyclic strain induced tyrosine phosphorylation and reorganization of pp125FAK and paxillin and suggest that these focal adhesion proteins play a specific role in cyclic strain-induced morphological change and migration.

scholarly journals VASCULAR INJURY CHANGE TYROSINE PHOSPHORYLATION OF FOCAL ADHESION PROTEINS

Heart ◽  
2012 ◽  
Vol 98 (Suppl 2) ◽  
pp. E55.2-E55
Author(s):  
Song ZhiQing ◽  
Guo Wen ◽  
Song ZhiQing
Keyword(s):  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Vascular Injury ◽  
Adhesion Proteins ◽  
Focal Adhesion Proteins

Role of tyrosine kinase pathways in ETB receptor activation of NHE3

1996 ◽  
Vol 271 (3) ◽  
pp. C763-C771 ◽  
Author(s):  
T. S. Chu ◽  
H. Tsuganezawa ◽  
Y. Peng ◽  
A. Cano ◽  
M. Yanagisawa ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Integral Membrane Protein ◽  
Receptor Activation ◽  
Kinase C ◽  
Focal Adhesion Proteins ◽  
Etb Receptor

Endothelin-1 (ET-1) binding to ETB receptors increases the activity of the apical membrane Na+/H+ antiporter (NHE3) of renal proximal tubule and cultured OKP cells. In OKPETB6 cells, a clonal cell line of OKP cells that overexpresses ETB receptors, ET-1-induced increases in Na+/H+ antiporter activity are mediated 50% by Ca2(+)-dependent pathways and 50% by tyrosine kinase pathways. ET-1 induces tyrosine phosphorylation of proteins of 68, 110, 125, 130, and 210 kDa. ET-1-induced tyrosine phosphorylation is mediated by the ETB receptor and is not dependent on increases in cell Ca2+ or protein kinase C. The 68-, 110-, 125-, and 130-kDa phosphoproteins are cytosolic, whereas the 210-kDa phosphoprotein is an integral membrane protein. Immunoprecipitation studies showed that the 68-kDa protein is paxillin and the 125-kDa protein is p125FAK (focal adhesion kinase). Cytochalasin D, which disrupts focal adhesions, prevented ET-1-induced tyrosine phosphorylation of paxillin, p110, p125FAK, and p130 but did not prevent tyrosine phosphorylation of p210 and did not prevent ET-1-induced increases in Na+/H+ antiporter activity. Thus 50% of ETB receptor-induced Na+/H+ antiporter activation is mediated by tyrosine kinase pathways, possibly involving p210. ETB receptor activation also induces tyrosine phosphorylation of focal adhesion proteins, but this is not required for antiporter activation.

scholarly journals Uncoupling Crk Signal Transduction by Pseudomonas Exoenzyme T

2005 ◽  
Vol 280 (43) ◽  
pp. 35953-35960 ◽  
Author(s):  
Qing Deng ◽  
Jianjun Sun ◽  
Joseph T. Barbieri
Keyword(s):  
Focal Adhesion ◽  
Rho Gtpase ◽  
Adaptor Proteins ◽  
Sh2 Domain ◽  
Integrin Signaling ◽  
Gtpase Activating Protein ◽  
Adhesion Proteins ◽  
Adp Ribosylation ◽  
Focal Adhesion Proteins ◽  
Adp Ribosyltransferase

Exoenzyme T (ExoT) is a bifunctional type III cytotoxin of Pseudomonas aeruginosa that possesses both Rho GTPase-activating protein and ADP-ribosyltransferase activities. The ADP-ribosyltransferase activity of ExoT stimulated depolymerization of the actin cytoskeleton independent of Rho GTPase-activating protein function, and ExoT was subsequently shown to ADP-ribosylate Crk (CT10 regulator of kinase)-I and Crk-II. Crk proteins are eukaryotic adaptor proteins comprising SH2 and SH3 domains that are components of the integrin signaling pathway leading to Rac1 and Rap1 functions. Mass spectroscopic analysis identified Arg20 as the site of ADP-ribosylation by ExoT. Arg20 is a conserved residue located within the SH2 domain that is required for interactions with upstream signaling molecules such as paxillin and p130cas. Glutathione S-transferase pull-down and far Western assays showed that ADP-ribosylated Crk-I or Crk-I(R20K) failed to bind p130cas or paxillin. This indicates that ADP-ribosylation inhibited the direct interaction of Crk with these focal adhesion proteins. Overexpression of wild-type Crk-I reduced cell rounding by ExoT, whereas expression of dominant-active Rac1 interfered with the ability of ExoT to round cells. Thus, the ADP-ribosylation of Crk uncouples integrin signaling by direct inhibition of the binding of Crk to focal adhesion proteins.

scholarly journals Csk enhances insulin-stimulated dephosphorylation of focal adhesion proteins.

1996 ◽  
Vol 16 (9) ◽  
pp. 4765-4772 ◽  
Author(s):  
K Tobe ◽  
H Sabe ◽  
T Yamamoto ◽  
T Yamauchi ◽  
S Asai ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Tyrosine Kinases ◽  
Kinase Activity ◽  
Cell Physiology ◽  
Insulin Receptor Tyrosine Kinase ◽  
Adhesion Proteins ◽  
Focal Adhesion Proteins ◽  
Focal Adhesion Protein

Insulin has pleiotropic effects on the regulation of cell physiology through binding to its receptor. The wide variety of tyrosine phosphorylation motifs of insulin receptor substrate 1 (IRS-1), a substrate for the activated insulin receptor tyrosine kinase, may account for the multiple functions of insulin. Recent studies have shown that activation of the insulin receptor leads to the regulation of focal adhesion proteins, such as a dephosphorylation of focal adhesion kinase (pp125FAK). We show here that C-terminal Src kinase (Csk), which phosphorylates C-terminal tyrosine residues of Src family protein tyrosine kinases and suppresses their kinase activities, is involved in this insulin-stimulated dephosphorylation of focal adhesion proteins. We demonstrated that the overexpression of Csk enhanced and prolonged the insulin-induced dephosphorylation of pp125FAK. Another focal adhesion protein, paxillin, was also dephosphorylated upon insulin stimulation, and a kinase-negative mutant of Csk was able to inhibit the insulin-induced dephosphorylation of pp125FAK and paxillin. Although we have shown that the Csk Src homology 2 domain can bind to several tyrosine-phosphorylated proteins, including pp125FAK and paxillin, a majority of protein which bound to Csk was IRS-1 when cells were stimulated by insulin. Our data also indicated that tyrosine phosphorylation levels of IRS-1 appear to be paralleled by the dephosphorylation of the focal adhesion proteins. We therefore propose that the kinase activity of Csk, through the insulin-induced complex formation of Csk with IRS-1, is involved in insulin's regulation of the phosphorylation levels of the focal adhesion proteins, possibly through inactivation of the kinase activity of c-Src family kinases.

RhoA required for acid-induced stress fiber formation and trafficking and activation of NHE3

2007 ◽  
Vol 293 (4) ◽  
pp. F1054-F1064 ◽  
Author(s):  
Xiaojing Yang ◽  
Hai-Chang Huang ◽  
Helen Yin ◽  
Robert J. Alpern ◽  
Patricia A. Preisig
Keyword(s):  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Apical Membrane ◽  
Rho Kinase ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Adhesion Proteins ◽  
Stress Fiber Formation ◽  
Induced Stress ◽  
Focal Adhesion Proteins

Exposure to an acid load increases apical membrane Na+/H+ antiporter (NHE3) activity, a process that involves exocytic trafficking of the transporter to the apical membrane. We have previously shown that an intact microfilament structure is required for this exocytic process (Yang X, Amemiya M, Peng Y, Moe OW, Preisig PA, Alpern RJ. Am J Physiol Cell Physiol 279: C410–C419, 2000). The present studies demonstrate that acid-induced stress fiber formation is required for stimulation of NHE3 activity. Formation of stress fibers is associated with acid-induced tyrosine phosphorylation and increases in protein abundance of two focal adhesion proteins, p125FAK and paxillin. The Rho kinase inhibitor Y27632 completely blocks acid-induced stress fiber formation and the increases in apical membrane NHE3 abundance and activity, but it has no effect on acid-induced tyrosine phosphorylation of p125FAK or paxillin. Herbimycin A completely blocks acid-induced tyrosine phosphorylation of p125FAK and paxillin but only partially blocks stress fiber formation and NHE3 activation. These studies demonstrate that Rho kinase mediates acid-induced stress fiber formation, which is required for NHE3 exocytosis, and increases in NHE3 activity. Acid-induced tyrosine phosphorylation of the focal adhesion proteins p125FAK and paxillin is not Rho kinase dependent. Thus these two acid-mediated effects are associated, yet independent processes.

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