Activation of RAC-protein kinase by heat shock and hyperosmolarity stress through a pathway independent of phosphatidylinositol 3-kinase.
RAC protein kinase (RAC-PK), a serine/threonine protein kinase containing a pleckstrin homology (PH) domain, was activated by cellular stress such as heat shock and hyperosmolarity. Wortmannin, which is known as a potent inhibitor of phosphatidylinositol 3-kinase and normally inhibits growth factor-induced activation of RAC-PK, did not suppress heat-shock induced activation of RAC-PK, indicating that this stress-induced activation of the kinase is not mediated by phosphatidylinositol 3-kinase. The PH domain was indispensable for stress-induced activation of RAC PK. In heat-treated cells, PKC delta, a member of the protein kinase C family, was found to associate with the PH domain of RAC-PK. This PKC subspecies was phosphorylated in vitro by RAC-PK. The results suggest that RAC-PK may play a role in the cellular response to stress through its PH domain.
Konishi
H
H
Biosignal Research Center, Kobe University, Japan.
Matsuzaki
H
H
Tanaka
M
M
Ono
Y
Y
Tokunaga
C
C
Kuroda
S
S
Kikkawa
U
U
D016475:3T3 Cells; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D001798:Blood Proteins / Q000737:chemistry; D002460:Cell Line; D002522:Chlorocebus aethiops; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006358:Hot Temperature; D007527:Isoenzymes / Q000378:metabolism*; D051379:Mice; D009842:Oligopeptides; D009994:Osmolar Concentration; D010455:Peptides; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D051745:Protein Kinase C-delta; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D016324:Sequence Tagged Sites; D013012:Sorbitol / Q000494:pharmacology; D013312:Stress, Physiological; D014162:Transfection; D000077191:Wortmannin
D000730:Androstadienes; D000841:Anisomycin; D001798:Blood Proteins; D003513:Cycloheximide; D003609:Dactinomycin; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D009842:Oligopeptides; D010455:Peptides; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D017853:Phosphotransferases (Alcohol Group Acceptor); D010982:Platelet-Derived Growth Factor; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D011994:Recombinant Proteins; D013012:Sorbitol; D000077191:Wortmannin; C039077:platelet protein P47; C085706:FLAG peptide; C497259:Prkcd protein, mouse; C497260:Prkcd protein, rat