Rheb

TSC1 is a tumor suppressor gene that encodes a 130 kDa protein called hamartin. TSC1 was first identified as an oncogenic driver of Tuberous Sclerosis, a condition characterized by numerous benign tumors of the skin, brain, heart, and lungs. A mutation in TSC1 is responsible for the uncontrolled growth characteristic of these tumors. This discovery led to a greater understanding of the physiologic role of TSC1 as a negative cell cycle regulator. The distinct but related gene TSC2 encodes a 200 kDa protein called tuberin.

The mammalian target of rapamycin (mTOR) signaling pathway allows cells to monitor environmental signals like nutrient availability and oxygen levels. mTOR is a phosphoinositide 3-kinase (PI3K)-related protein that assembles into large protein complexes (mTORC1 and mTORC2) capable of regulating cell metabolism, growth, and proliferation.