Cell Cycle Suppression
pRb prevents the cell from replicating damaged DNA by preventing its progression along the cell cycle through G1 (first gap phase) into S (synthesis phase). pRb binds and inhibits transcription factors of the E2F family, which are composed of dimers of an E2F protein and a DP protein. The transcription activating complexes of E2 promoter-binding–protein-dimerization partners (E2F-DP) can push a cell into S phase. As long as E2F-DP is inactivated, the cell remains stalled in the G1 phase. When pRb is bound to E2F, the complex acts as a growth suppressor and prevents progression through the cell cycle. The pRb-E2F/DP complex also attracts a histone deacetylase (HDAC) protein to the chromatin, reducing transcription of S phase promoting factors, further suppressing DNA synthesis.
Read more about this topic: Retinoblastoma Protein
Famous quotes containing the words cell, cycle and/or suppression:
“Women have no wilderness in them,
They are provident instead,
Content in the tight hot cell of their hearts
To eat dusty bread.”
—Louise Bogan (1897–1970)
“The Buddha, the Godhead, resides quite as comfortably in the circuits of a digital computer or the gears of a cycle transmission as he does at the top of a mountain or in the petals of a flower.”
—Robert M. Pirsig (b. 1928)
“Rationalists are admirable beings, rationalism is a hideous monster when it claims for itself omnipotence. Attribution of omnipotence to reason is as bad a piece of idolatry as is worship of stock and stone believing it to be God. I plead not for the suppression of reason, but for a due recognition of that in us which sanctifies reason.”
—Mohandas K. Gandhi (1869–1948)