Hidenori Sasa (1), Hiroko Nakata (2), Tadashi Umekage(2), Misako Namima
(2), Koji Tomiyama (2), Shinya Arimura (2), Mitsunao Kobayashi (1) and Yasuhiro
(1) Department of Perinatal and Maternal Medicine and (2) Department of Pharmacology, National Defense Medical College, Tokorozawa, Saitama 359, Japan
Abstract: GTPase-activating proteins (GAPs) stimulate the hydrolysis of GTP bound to small G-proteins and regulate the signal transduction pathway. Changes in the expression of p21-Ras p120-GAP induced by growth factor treatment were examined in cultured Chinese hamster ovary (CHO) and human choriocarcinoma (BeWo) cells. Expression of p120-GAP and GAP activity were measured. Fetal bovine serum induced a significant increased level of GAP in CHO cells, but did not increase GAP in BeWo cells. The results suggest that growth factors affect Ras GAP expression in CHO cells, while they do not in other cells such as BeWo cells.
Keywords: GTPase-activating protein, Growth factor, Immunoblot analysis