Does RB inhibit E2F1?

Abstract. Forced expression of the retinoblastoma (RB) gene product inhibits the proliferation of cells in culture. A major target of the RB protein is the S-phase-inducing transcription factor E2F1. RB binds directly to the activation domain of E2F1 and silences it, thereby preventing cells from entering S phase.

What is E2F and Rb?

The RB/E2F pathway regulates apoptosis, and RB inhibition of apoptosis is an important mechanism of tumor suppression whereby cells deficient for RB function can be eliminated by apoptosis. One manner through which RB can inhibit apoptosis is through its binding to RNA processing factors.

How does RB regulate E2F?

Rb proteins are thought to inhibit expression of E2F-regulated genes in two ways (Dyson et al., 2002): by directly binding and blocking the activation domain of E2F proteins or by active repression through the recruitment of HDAC, SWI/SNF factors, Polycomb group proteins (Dahiya et al., 2001) or methyltransferase ( …

What is the function of RB?

The Rb protein is a tumor suppressor, which plays a pivotal role in the negative control of the cell cycle and in tumor progression. It has been shown that Rb protein (pRb) is responsible for a major G1 checkpoint, blocking S-phase entry and cell growth.

What cancers are associated with Rb gene?

In addition to bladder cancer, somatic mutations in the RB1 gene are associated with many other types of cancer. For example, changes in the RB1 gene have been reported in some cases of lung cancer, breast cancer, a bone cancer known as osteosarcoma, and an aggressive form of skin cancer called melanoma.

How does Rb inhibit cell cycle?

The retinoblastoma protein is an inhibitor of cell cycle progression from the G1 to the S phase of the cell cycle. It acts through its ability to interact with cellular target molecules such as E2F transcription factors.

What is Rb gene?

The retinoblastoma (RB) gene is the prototype tumor suppressor gene. It encodes a nuclear protein that acts as a cell cycle control checkpoint at the G1 phase.

How is Rb a Tumour suppressor?

The RB tumor suppressor protein limits cell proliferation by preventing entry into the S phase of the cell cycle. RB achieves its inhibitory effect by blocking the activity of E2F.

Is pRB a tumor suppressor gene?

Normal Function. The RB1 gene provides instructions for making a protein called pRB. This protein acts as a tumor suppressor, which means that it regulates cell growth and keeps cells from dividing too fast or in an uncontrolled way.

What is Rb mutation?

The retinoblastoma gene, Rb, was originally identified as the tumor suppressor gene mutated in a rare childhood cancer called retinoblastoma (reviewed in [1]. Subsequent studies showed that Rb functions in a pathway that is often functionally inactivated in a large majority of human cancers.