Pathways & interactions
Rap/Ran-GAP superfamily (IPR035974)
Short name: Rap/Ran-GAP_sf
- Rap GTPase activating protein domain (IPR000331)
- Tuberin (IPR003913)
- Tuberin/Ral GTPase-activating protein subunit alpha (IPR027107)
- Signal-induced proliferation-associated 1-like protein 1 (IPR030770)
- Signal-induced proliferation-associated 1-like protein 2 (IPR031203)
Rap small G proteins have been implicated in various cellular processes such as exocytosis, cAMP signalling, cell adhesion and cell proliferation. Rap proteins acts as molecular switches, with an active GTP-bound form and an inactive GDP-bound form [PMID: 11331911]. The inactive GDP bound form is promoted by GTPase-activating proteins (GAPs). GAP proteins specific for Rap contain a conserved region of around 200 amino-acid residues, the RapGAP domain. This domain can accelerate the GTP hydrolysis activity of Rap by five orders of magnitude [PMID: 9346962].
Proteins known to contain a Rap-GAP domain include:
- RAP1 GTPase activating protein (RAP1GAP).
- Mammalian tuberin protein, the product of a familial tuberous sclerosis gene which, when deleted, causes begnin tumours. It also have a GAP activity for Rab5 [PMID: 9045618].
- Drosophila Gigas protein, an homologue of tuberin involved in regulation of cell cycle.
- Mammalian tuberin-like protein TULIP.
- GTPase-activating protein Spa-1. It functions as a negative regulator for the activation of Rap1, thereby having a negative effect on cell adhesion [PMID: 10373454].