CASTOR family (IPR026249)

Short name: CASTOR_fam

Overlapping homologous superfamilies


Family relationships


CASTOR family members are well-conserved in eukaryotes (including human, chimpanzee, dog, cow, mouse, rat, chicken, zebrafish) [PMID: 16305752, PMID: 19468303]. To date, in addition to the putative CASTOR protein, three subtypes, designated CASTOR1, CASTOR2 and CASTOR3 have been identified in humans.

CASTOR1 can form homodimers and bind arginine. It can also form heterodimers with GATOR2. The arginine binding of CASTOR1 disrupts the CASTOR1-GATOR2 interaction, and this triggers downstream activation of mTORC1 [PMID: 27487210]. Therefore, CASTOR1 functions as an intracellular arginine sensor for the mTORC1 Pathway [PMID: 26972053, PMID: 27487210]. Interestingly, CASTOR1 shares substantial structural homology with the lysine-binding regulatory domain of prokaryotic aspartate kinases [PMID: 27487210].

Contributing signatures

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