Cytosolic arginine sensor for mTORC1 subunit 2 (Castor2)

Functions as a negative regulator of this TORC1 signaling pathway throughout the GATOR complex. As part of homodimers or heterodimers with CASTOR1, directly binds and inhibits the GATOR subcomplex GATOR2 and thereby mTORC1.

Doesn't directly bind arginine, but binding of arginine to CASTOR1 disrupts the interaction of CASTOR2-containing heterodimers with GATOR2 which can in turn trigger mTORC1 and the TORC1 signaling pathway. .