ANG II and LPA induce Pyk2 tyrosine phosphorylation in intestinal epithelial cells: role of Ca2+, PKC, and Rho kinase.
The G protein-coupled receptor agonists angiotensin II (ANG II) and lysophosphatidic acid (LPA) rapidly induce tyrosine phosphorylation of the cytosolic proline-rich tyrosine kinase 2 (Pyk2) in IEC-18 intestinal epithelial cells. The combined Pyk2 tyrosine phosphorylation induced by phorbol 12,13-dibutyrate, a direct agonist of protein kinase C (PKC), and ionomycin, a Ca2+ ionophore, was equal to that induced by ANG II. Inhibition of either PKC or Ca2+ signaling attenuated the effect of ANG II and LPA, although simultaneous inhibition of both pathways failed to completely abolish Pyk2 tyrosine phosphorylation. Cytochalasin D, which disrupts stress fibers, strongly inhibited the response of Pyk2 to ANG II or LPA. The distinct Rho-associated kinase (ROK) inhibitors HA-1077 and Y-27632, as well as the Rho inhibitor Clostridium botulinum C3 exoenzyme, also significantly attenuated ANG II- and LPA-stimulated Pyk2 tyrosine phosphorylation. Simultaneous inhibition of PKC, Ca2+, and either actin assembly or ROK completely abolished the Pyk2 response. Together, these results show that ANG II and LPA rapidly induce Pyk2 tyrosine phosphorylation in intestinal epithelial cells via separate Ca2+-, PKC-, and Rho-mediated pathways.
Wu
Steven S
SS
Department of Pediatrics, School of Medicine and Molecular Biology Institute, University of California, Los Angeles, California 90095-1786, USA.
Chiu
Terence
T
Rozengurt
Enrique
E
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D015638:Cytochalasin D / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051418:Focal Adhesion Kinase 2; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007476:Ionophores / Q000494:pharmacology; D008246:Lysophospholipids / Q000494:pharmacology*; D051419:Paxillin; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011233:Precipitin Tests; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D054460:rho-Associated Kinases
D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D007476:Ionophores; D008246:Lysophospholipids; D051419:Paxillin; D010750:Phosphoproteins; C496063:Pxn protein, rat; D010566:Virulence Factors, Bordetella; D000804:Angiotensin II; D015638:Cytochalasin D; D015240:Phorbol 12,13-Dibutyrate; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; C496054:Ptk2b protein, rat; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D011493:Protein Kinase C; D002118:Calcium