Association of p21ras with phosphatidylinositol 3-kinase.

Phosphatidylinositol-3 kinase regulates p21ras activation during IgE-mediated stimulation of human basophils.

Cross-linking of IgE or a bacterial product (f-Met-Leu-Phe; FMLP) induces the release of leukotriene C4 (LTC4) and histamine in human basophils. However, the signaling mechanisms in human basophils are only partially understood. It has been demonstrated that extracellular signal-regulated kinases (ERK1/2) specifically regulate the pathway for LTC4 generation, but not for histamine release and i...

Biphasic activation of p21ras by endothelin-1 sequentially activates the ERK cascade and phosphatidylinositol 3-kinase.

Endothelin-1 (ET-1) induces cell proliferation and differentiation through multiple G-protein-linked signaling systems, including p21ras activation. Whereas p21ras activation and desensitization by receptor tyrosine kinases have been extensively investigated, the kinetics of p21ras activation induced by engagement of G-protein-coupled receptors remains to be fully elucidated. In the present stu...

Stimulation of phosphatidylinositol 3'-kinase association with foca adhesion kinase by platelet-derived growth factor.

We have previously described the stable association of the focal adhesion kinase (FAK) with phosphatidylinositol 3'-kinase (PI3K) in NIH 3T3 cells. This interaction was stimulated by cell adhesion in vivo and by autophosphorylation of recombinant FAK in vitro. In this report, we show that platelet-derived growth factor (PDGF) could also specifically stimulate this association in vivo. This stim...

Involvement of Phosphatidylinositol 3-Kinase

Calmodulin activates phosphatidylinositol 3-kinase.

Calmodulin and phosphatidylinositol 3-kinase are vital components of a number of common intracellular events. Calmodulin, a ubiquitous Ca2+-dependent effector protein, regulates multiple processes in eukaryotic cells, including cytoskeletal organization, vesicular trafficking, and mitogenesis. Phosphatidylinositol 3-kinase participates in events downstream of the receptors for insulin and other...