Small GTPase Ras and Rho Expression in Rat Osteoblasts during Spaceflight
Rat osteoblasts were cultured for 4 and 5 days aboard a space shuttle and solubilized after a 24-h treatment with 1?,25 dihydroxyvitamin D3. The quantitative RT-PCR determined the mRNA levels of signaling molecules upstream and downstream Ras. The small GTPase is activated by guanine nucleotide exchange protein (GEF) and deactivated by GTPase-activating protein (GAP). When external stimuli are transduced into intracellular signals, various pathways are recruite
ras rho osteoblast spaceflight gravity g protein sos plc fak