Ras guanyl nucleotide releasing protein 2 affects cell viability and cell-matrix adhesion in ECV304 endothelial cells.

Ras guanyl nucleotide releasing proteins (RasGRPs) are guanine nucleotide exchange factors that activate Ras and Rap. We recently reported that xrasgrp2, which is a homolog of the human rasgrp2, plays a role in vasculogenesis and/or angiogenesis during early development of Xenopus embryos. However, the function of RasGRP2 in human vascular endothelium remains unknown. Therefore we aimed to analyze the function of human RasGRP2 in vascular endothelial cells. RasGRP2 overexpression did not increase Ras activation. However, it slightly increased Ras expression and increased proliferation in ECV304 cells. Furthermore, RasGRP2 overexpression increased Rap1 activation and cell-matrix adhesion in ECV304 cells. These data demonstrate that RasGRP2 increases cell viability and cell-matrix adhesion through increased Ras expression and Rap1 activation, respectively, in endothelial cells.