Tuberin/Ral GTPase-activating protein subunit alpha (IPR027107)

Short name: Tuberin/Ral-act_asu

Overlapping homologous superfamilies


Family relationships

  • Tuberin/Ral GTPase-activating protein subunit alpha (IPR027107)


The activity of GTPases is regulated by the opposing effects of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Tuberin (tuberous sclerosis 2 protein or Tsc2) is believed to be a tumor suppressor and is able to stimulate specific GTPases. It stimulates the intrinsic GTPase activity of the Ras-related protein Rap1A and Rab5 [PMID: 8806680, PMID: 9045618]. In complex with Tsc1, inhibits the nutrient-mediated or growth factor-stimulated phosphorylation of S6K1 and EIF4EBP1 by negatively regulating mTORC1 signaling. It acts as a GTPase-activating protein (GAP) for the small GTPase RheB, a direct activator of the protein kinase activity of mTORC1 [PMID: 12271141, PMID: 15340059].

Ral GTPase-activating protein subunit alpha is the catalytic subunit of the heterodimeric RalGAP complex which acts as a GTPase activator for the Ras-like small GTPases RalA and RalB [PMID: 19520869]. RalGAP complexes share structural and catalytic similarities with the tuberous sclerosis tumor suppressor complex [PMID: 19520869].

This family also includes the uncharacterised protein C18B11.11 from yeast.

GO terms

Biological Process

GO:0043547 positive regulation of GTPase activity

Molecular Function

GO:0005096 GTPase activator activity

Cellular Component

GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.