Regulatory-associated protein of mTOR (RAPTOR) (RAPTOR)

Regulatory-associated protein of mTOR (RAPTOR) is a vital scaffolding protein that serves as a defining component of the Mechanistic Target of Rapamycin Complex 1 (mTORC1) (UniProt: P83483). It plays a central role in cellular regulation by recruiting substrates, such as EIF4EBP1 and RPS6KB1, to the mTOR kinase for phosphorylation, which subsequently drives protein synthesis, lipid synthesis, and cell growth (PubMed: 12150925). RAPTOR acts as a nutrient sensor, responding to amino acid availability to modulate mTORC1 activity and maintain metabolic homeostasis (PubMed: 15467718). In various malignancies, the mTORC1 pathway is frequently dysregulated, leading to uncontrolled proliferation and survival, which positions RAPTOR as a significant therapeutic target (PubMed: 22566320). Drugs like rapamycin and its analogs (rapalogs) exert their effects by binding to FKBP12 and associating with the mTOR complex, which can disrupt the RAPTOR-mTOR interaction or inhibit the complex's assembly (PubMed: 12150926). Consequently, RAPTOR is a key focus in the development of treatments for cancer, metabolic disorders, and age-related diseases.

Other names

RPTORKOG1Regulatory-associated protein of mTOR

RAPTOR functions as a substrate adapter that recruits proteins containing a TOR signaling (TOS) motif to the mTORC1 complex for phosphorylation (PubMed: 12150925). Therapeutic agents like rapamycin and its derivatives bind to the intracellular protein FKBP12; this drug-protein complex then binds to the FRB domain of mTOR, which sterically interferes with the recruitment of substrates by RAPTOR or destabilizes the mTOR-RAPTOR association, effectively inhibiting mTORC1-mediated signaling (PubMed: 12150926, PubMed: 22566320).