Role of c-SRC and ERK in acid-induced activation of NHE3
| Autor: | Soichiro Sato, Hirohiko Tsuganezawa, Patricia A. Preisig, Robert J. Alpern, Yasuyoshi Yamaji, Orson W. Moe |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
c-fos
Male MAPK/ERK pathway medicine.medical_specialty Sodium-Hydrogen Exchangers OKP cells Protein Serine-Threonine Kinases Ammonium Chloride 3T3 cells CSK Tyrosine-Protein Kinase Rats Sprague-Dawley NIH 3T3 cells Internal medicine medicine Animals renal acidification Phosphorylation Incubation Cells Cultured Mitogen-Activated Protein Kinase 1 Mitogen-Activated Protein Kinase 3 biology Sodium-Hydrogen Exchanger 3 urogenital system Kinase JNK Mitogen-Activated Protein Kinases Na/H antiporter Transfection Protein-Tyrosine Kinases Apical membrane Molecular biology Rats Enzyme Activation src-Family Kinases medicine.anatomical_structure Endocrinology PD98059 Nephrology Mitogen-activated protein kinase biology.protein MAP kinase Src kinase JNK Mitogen-Activated Protein Kinases Acidosis Proto-Oncogene Proteins c-fos Proto-oncogene tyrosine-protein kinase Src |
| Zdroj: | Kidney International. 62:41-50 |
| ISSN: | 0085-2538 |
| Popis: | Role of c-Src and ERK in acid-induced activation of NHE3. Background In the renal proximal tubule, chronic acidosis causes increases in apical membrane NHE3 activity, which serve to increase transepithelial H + secretion and return systemic pH to normal levels. Incubation of cultured renal epithelial cells in acid media activates c-Src. Methods OKP cells were incubated in control (pH 7.4) or acid (7.0) media, and NHE3 activity measured as cytoplasmic pH (pHi) recovery from an acid load using BCECF. c-Src, ERK, and JNK kinase activities were measured by immune complex kinase assays with enolase, MBP, and GST-c-Jun, respectively, as substrates in the in vitro assays. To determine the role of c-Src in acid-induced NHE3 activation, cells were transfected with vector alone or a dominant negative c-Src (c-Src K295M ). Results Expression of dominant negative c-src K295M in OKP cells prevented acid-induced activation of NHE3. Incubation of OKP cells in acid media increased ERK activity and c-fos expression, but did not increase JNK activity. Acidosis in vivo also activated renal cortical c-Src and ERK kinases, whereas incubation of 3T3 cells in acid media activated c-Src but not ERK kinase. Expression of c-src K295M did not affect ERK or c-fos activation by acid incubation. Inhibition of MEK with PD98059 inhibited activation of NHE3 by acid incubation. Conclusions These studies suggest that acidosis activates c-Src and MEK/ERK/ c-fos . While both pathways are necessary for activation of NHE3, they are activated independently. |
| Databáze: | OpenAIRE |
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