Ras-related protein Rap-1b (RAP1B)

Ras-related protein Rap-1b (RAP1B) is a member of the small GTPase superfamily, specifically the RAS-like GTPase subfamily. RAP1B functions as a molecular switch cycling between inactive GDP-bound and active GTP-bound states, playing a central role in regulating integrin-mediated cell adhesion, cell polarity, and vascular integrity. It acts by binding effectors such as talin and orchestrating the localization and activation of integrins at the cell membrane, crucial for processes ranging from platelet aggregation (hemostasis) to endothelial cell junction formation. RAP1B is ubiquitously expressed but is particularly abundant in platelets, endothelial cells, and various tissues where precise regulation of cell-cell and cell-matrix interactions is essential. Dysregulation of RAP1B function is implicated in thrombocytopenia, developmental syndromes such as Kabuki syndrome, and various disorders of cell adhesion and proliferation

Other names

GTP-binding protein smg p21BOK/SW-cl.11K-REVRAL1BDKFZp586H0723THC11Ras family small GTP binding protein RAP1Bsmall GTP binding protein RAP1BRAS-related protein RAP1B

Not directly targeted by known clinical drugs; potential mechanisms include inhibition or modulation of GTPase activity, disruption of effector binding (e.g., to talin, integrin complexes), or interference with prenylation required for membrane localization