Cytosolic arginine sensor for mTORC1 subunit 2 (CASTOR2)

CASTOR2 (Cytosolic arginine sensor for mTORC1 subunit 2) is a cytosolic protein that serves as a negative regulator of the mTORC1 signaling pathway by sensing cellular arginine levels. It is structurally related to CASTOR1 but differs functionally; unlike CASTOR1, CASTOR2 does not bind arginine and constitutively associates with the GATOR2 complex[3]. CASTOR2 forms homodimers or heterodimers with CASTOR1, and these complexes interact with GATOR2 to inhibit mTORC1 activation in response to amino acid levels. CASTOR2 is part of a critical regulatory network controlling cell growth and metabolism via mTORC1 signaling, with potential relevance in cancer and other diseases characterized by abnormal cell growth or nutrient sensing[3][5][4].

Other names

GATSL1GATSL2Cellular arginine sensor for mTORC1 protein 2GATS-like protein 2GATS-like protein 1GATS protein-like 1GATS protein-like 2

Not applicable; No drugs directly target CASTOR2. Pathway drugs (e.g., mTOR inhibitors like rapamycin) act downstream of CASTOR2 regulation[1][3].