Activation of RAC-protein kinase by heat shock and hyperosmolarity stress through a pathway independent of phosphatidylinositol 3-kinase

摘要: Abstract RAC protein kinase (RAC-PK), a serine/threonine containing pleckstrin homology (PH) domain, was activated by cellular stress such as heat shock and hyperosmolarity. Wortmannin, which is known potent inhibitor of phosphatidylinositol 3-kinase normally inhibits growth factor-induced activation RAC-PK, did not suppress heat-shock induced indicating that this stress-induced the mediated 3-kinase. The PH domain indispensable for RAC PK. In heat-treated cells, PKC delta, member C family, found to associate with RAC-PK. This subspecies phosphorylated in vitro results suggest RAC-PK may play role response through its domain.