What does the mTOR pathway do?

The mTOR signaling pathway, which is often activated in tumors, not only regulates gene transcription and protein synthesis to regulate cell proliferation and immune cell differentiation but also plays an important role in tumor metabolism.

What is phospho mTOR?

Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that plays a key role in cell growth, cell proliferation, and protein synthesis. mTOR mediates phosphoinositide 3-kinase and Akt/PKB signaling, resulting in phosphorylation of 4EBP1, and initiation of mRNA translation.

How does mTOR regulate autophagy?

mTORC1 tightly regulates autophagy by suppressing autophagy induction via phosphorylation-dependent inhibition of ULK1/2 and the VPS34 complex and by preventing global expression of lysosomal and autophagy genes through TFEB phosphorylation.

What does TOR kinase do?

TOR protein kinase is an amino acid and nutrients sensor that stimulates growth and blocks pathways salvage, such as autophagy when food is abundant. Inhibiting TOR pathway increases lifespan in many species, from yeast to mice [76–78].

What happens if you inhibit mTOR?

The inhibition of mTOR blocks the binding of the accessory protein raptor (regulatory-associated protein of mTOR) to mTOR, but that is necessary for downstream phosphorylation of S6K1 and 4EBP1. As a consequence, S6K1 dephosphorylates, which reduces protein synthesis and decreases cell mortality and size.

What happens when mTOR is phosphorylated?

mTORC1-mediated phosphorylation of S6K1 aids the assembly of the eukaryotic initiation factor 3 (eIF3) translation initiation complex, while phosphorylation of the translational repressor 4EBP1 induces its release from eIF4E, allowing eIF4E to initiate cap-dependent translation (28, 45).

How is mTOR activated?

Activation of mTOR complex 1 (mTORC1) is triggered by oxidative stress, amino-acid levels and endosomal traffic to the lysosome by small GTPases such as Rab4A. In turn, mTORC1 promotes inflammation by skewing T-cell development.

Does fasting suppress mTOR?

Because mTOR is a nutrient-sensing pathway, it can be deactivated by fasting and severe calorie restriction (CR), which exert metabolic effect that are somewhat similar, but not identical, to those of rapamycin42.

What is Tor enzyme?

TOR (Target Of Rapamycin) is a highly conserved protein kinase that is important in both fundamental and clinical biology. In fundamental biology, TOR is a nutrient-sensitive, central controller of cell growth and aging.