Cytosolic arginine sensor for mTORC1 subunit 1 (Castor1)

Functions as an intracellular arginine sensor inside the amino acid-sensing division of this TORC1 signaling pathway. As a homodimer or a heterodimer with CASTOR2, binds and inhibits the GATOR subcomplex GATOR2 and thereby mTORC1.

Binding of arginine into CASTOR1 allosterically disrupts the interaction of CASTOR1- containing dimers with GATOR2 which can in turn activate mTORC1 and the TORC1 signaling pathway. .