Sema4D mediated inhibition of cell attachment and migration

Repulsive Sema4D-Plexin-B1 signaling involves four GTPases, Rnd1, R-Ras, Rho and Rac1. Sema4D-Plexin-B1 binding promotes Rnd1-dependent activation of the plexin-B1 GAP domain and transient suppression of R-Ras activity. R-Ras inactivation promotes PI3K and Akt inactivation followed by GSK-3beta activation and CRMP2 inactivation. Plexin-B1 also transiently associates with and activates p190Rho-GAP, triggering a transient decrease in activated Rho.

排斥性Sema4D-Plexin-B1信号通路涉及四种GTP酶，包括Rnd1、R-Ras、Rho和Rac1。Sema4D-Plexin-B1的结合促进Rnd1依赖性的plexin-B1 GAP结构域的激活以及R-Ras活性的短暂抑制。R-Ras的失活进而促进PI3K和Akt的失活，随后引发GSK-3beta的激活和CRMP2的失活。此外，plexin-B1还暂时与p190Rho-GAP结合并激活之，导致激活的Rho的暂时降低。