Mechanistic target of rapamycin complex 1 and 2 (mTORC1 and mTORC2) (mTORC1 and mTORC2)

The mechanistic target of rapamycin (mTOR) is a central serine/threonine protein kinase that functions as the catalytic subunit of two distinct multiprotein complexes, mTORC1 and mTORC2 [NIH, PubMed]. mTORC1 acts as a master regulator of cellular metabolism, integrating signals from nutrients, growth factors, and energy levels to promote anabolic processes like protein and lipid synthesis while suppressing catabolic processes such as autophagy [PubMed, UniProt]. In contrast, mTORC2 is primarily regulated by growth factors and plays a critical role in organizing the actin cytoskeleton and promoting cell survival through the phosphorylation of Akt [PubMed, Wikidoc]. Dysregulation of the mTOR signaling pathway is a common feature in various human diseases, particularly cancer, where hyperactivation leads to uncontrolled cell proliferation and survival [NIH]. It is also heavily implicated in metabolic disorders like type 2 diabetes and obesity, as well as neurodegenerative conditions and the aging process [PubMed]. Therapeutic strategies include first-generation rapalogs, which allosterically inhibit mTORC1, and second-generation ATP-competitive inhibitors that target both complexes to prevent compensatory feedback mechanisms [PubMed, NIH].

Other names

Mammalian target of rapamycin complex 1 and 2mTOR complex 1 and 2FRAP1 complexesRAFT1 complexesSEP complexes

Rapalogs (e.g., sirolimus) act as allosteric inhibitors of mTORC1 by forming a complex with FKBP12, which then binds to the FRB domain of mTOR [NIH]. Second-generation mTOR inhibitors are ATP-competitive antagonists that target the catalytic site of both mTORC1 and mTORC2, providing more complete inhibition of the pathway and preventing feedback activation of Akt [PubMed].