Retinitis pigmentosa 2 protein (RP2)

Retinitis pigmentosa 2 protein (RP2) is a GTPase-activating protein (GAP) that specifically inactivates the small GTPase ARL3 by stimulating its intrinsic GTP hydrolysis activity, converting active ARL3-GTP to inactive ARL3-GDP[1][2][3]. This process is a critical regulatory step in the trafficking and delivery of lipid-modified (prenylated and myristoylated) proteins to primary cilia, which are essential for sensory functions in specialized cells such as photoreceptors and kidney tubular cells[2][3][4]. RP2 is enriched at the base of the cilium and ensures spatial control of active ARL3, restricting ARL3 activation largely to the ciliary compartment where many of its functions are carried out[2][3]. Loss-of-function mutations in RP2 cause X-linked retinitis pigmentosa, a degenerative disease resulting in progressive vision loss, and broader disruptions of the RP2–ARL3 pathway are linked to other ciliopathies[3][4]. Note: - The query "RP2 activator of ARL3 GTPase" is somewhat misleading: RP2 acts as a **GTPase-activating protein** (GAP) for ARL3, promoting its inactivation, while activation of ARL3 is mediated by guanine nucleotide exchange factors (GEFs) such as ARL13B and BART[1][2][3]. - There is no evidence of approved drugs targeting RP2 directly[2][3][4]. - RP2 is important as a disease gene and functional regulator, but is not classified as a classic therapeutic "receptor". Core relationships: - ARL3 is a small GTPase switched 'on' by GEFs (ARL13B + BART) and 'off' by GAPs (RP2)[1][3]. - Mutations in RP2 disrupt ciliary protein trafficking and result in ciliopathies, especially inherited blindness[3][4].

Other names

Retinitis pigmentosa 2 proteinRP2GTPase-activating protein for ARL3GAP for ARL3

Increases GTP hydrolysis of ARL3, Leading to inactivation of ARL3, Modulation of ciliary protein transport