RAP1 GTPase-activating protein 2 (RAP1GAP2)

RAP1 GTPase-activating protein 2 (RAP1GAP2) is an enzyme that regulates the activity of Rap1, a small guanine-nucleotide-binding protein, by accelerating the hydrolysis of GTP to GDP on Rap1 in platelets[1][2][4][5]. This modulation is key in controlling integrin αIIbβ3 activation and platelet aggregation. RAP1GAP2 is expressed in several splice variants, predominantly in platelets and lymphocytes, and acts as a critical regulator at sites of endothelial damage, particularly by orchestrating dense granule secretion through interaction with synaptotagmin-like protein 1 and Rab27[1][3][4]. Its activity is modulated by NO/cGMP-dependent protein kinases, which phosphorylate RAP1GAP2, integrating signals that inhibit or promote platelet activation. Despite its clear regulatory role in platelets, there are currently no drugs directly targeting RAP1GAP2, though the protein may be indirectly affected by agents influencing NO/cGMP pathways[3].

Other names

GARNL4KIAA1039RAP1GA2RAP1GA3Rap1GAP2GTPase-activating Rap/Ran-GAP domain-like protein 4GTPase activating RANGAP domain-like 4

Indirect modulation by NO/cGMP signaling cascade: inhibits RAP1-mediated signaling through type I cGMP-dependent protein kinase (cGKI) phosphorylation. Platelet inhibitors using NO/cGMP may reduce RAP1GAP2's inhibitory function on platelet aggregation (indirect).