RAP1B siRNA – Ras-Related Protein Rap-1b Isoform 1 (Human)

This gene encodes a member of the RAS-like small GTP-binding protein superfamily. Members of this family regulate multiple cellular processes including cell adhesion and growth and differentiation. This protein localizes to cellular membranes and has been shown to regulate integrin-mediated cell signaling. This protein also plays a role in regulating outside-in signaling in platelets. Alternate splicing results in multiple transcript variants. Pseudogenes of this gene are found on chromosomes 3, 5, 6 and 9. [provided by RefSeq, Oct 2011]

RAP1B: GTP-binding protein that possesses intrinsic GTPase activity. Contributes to the polarizing activity of KRIT1 and CDH5 in the establishment and maintenance of correct endothelial cell polarity and vascular lumen. Required for the localization of phosphorylated PRKCZ, PARD3 and TIAM1 to the cell junction. Heterodimer with RAP1GAP. Interacts with EPAC2, SGSM1, SGSM2 and SGSM3. Activated by binding to the GTPase-activating protein RAP1GAP. Activated by guanine nucleotide-exchange factor (GEF) EPAC2 in a cAMP-dependent manner. Belongs to the small GTPase superfamily. Ras family.

Protein type: G protein, monomeric, Ras; G protein; G protein, monomeric

Chromosomal Location of Human Ortholog: 12q14

Cellular Component: membrane; plasma membrane; lipid particle; intercellular junction; intracellular; cytosol; lipid raft

Molecular Function: GTPase activity; protein binding; GDP binding; GTP binding; protein complex binding

Biological Process: microvillus biogenesis; platelet activation; cell proliferation; negative regulation of calcium ion-dependent exocytosis; metabolic process; blood coagulation; Rap protein signal transduction