Protein kinase Calpha and sphingosine 1-phosphate-dependent signaling in endothelial cell.

Protein kinase C (PKC)-mediated signal transduction pathways convert extracellular stimulation into a variety of cellular functions. However, the role of various PKC isoforms in sphingosine 1-phosphate (S1P)-stimulated endothelial cells is not well understood. PKCalpha and PKCepsilon activity are increased in endothelial cell cultures, and S1P receptor transfection studies indicate S1P(3) stimulates PKCalpha and S1P1 leads to PKCepsilon activity.

Role of guanine nucleotide exchange factor P-Rex-2b in sphingosine 1-phosphate-induced Rac1 activation and cell migration in endothelial cells.

Endothelial cell (EC) migration has an important role in angiogenesis. Sphingosine-1 phosphate (S1P) stimulates EC migration via activation of Gi proteins. In this study, we characterized a mouse guanine nucleotide exchange factor (GEF) P-Rex2b for its regulation by Gbetagamma and PI3K and its role in S1P-induced Rac1 activation and cell migration in ECs.

Regulation of PTEN by Rho small GTPases.

PTEN (phosphatase and tensin homologue) is a phosphatase that dephosphorylates both protein and phosphoinositide substrates. It is mutated in a variety of human tumours and has important roles in a diverse range of biological processes, including cell migration and chemotaxis. PTEN's intracellular localization and presumably activity are regulated by chemoattractants in Dictyostelium and mouse neutrophils.