REGULATION OF INOSITOL LIPID KINASES BY RHO AND RAC

Rho and Rac small GTPases associate with type-I phosphatidylinositol 4 -phosphate 5-kinase to regulate the production of phosphatidylinositol 4,5-bisphosphate. This lipid appears to mediate some of the effects o f Rho and Rac on the actin cytoskeleton. The genes for several type-I phosphatidylinositol 4-phosphate 5-kinases have been cloned recently b ut it is not known which one interacts with Rho and/or Rac. Rho family GTPases also interact with phosphatidylinositol 8-kinase, though this kinase can be either upstream or downstream of the GTPases depending upon the system.