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:
“It is plain that there is no separate essence called courage, no cup or cell in the brain, no vessel in the heart containing drops or atoms that make or give this virtue; but it is the right or healthy state of every man, when he is free to do that which is constitutional to him to do.”
—Ralph Waldo Emerson (1803–1882)
“Only mediocrities progress. An artist revolves in a cycle of masterpieces, the first of which is no less perfect than the last.”
—Oscar Wilde (1854–1900)
“A state that denies its citizens their basic rights becomes a danger to its neighbors as well: internal arbitrary rule will be reflected in arbitrary external relations. The suppression of public opinion, the abolition of public competition for power and its public exercise opens the way for the state power to arm itself in any way it sees fit.... A state that does not hesitate to lie to its own people will not hesitate to lie to other states.”
—Václav Havel (b. 1936)