Identify the normal functions of the following genes whose mutations are associated with the development of cancer.
RB1(retinoblastoma)

Verified step by step guidance

1. Understand that the RB1 gene is a tumor suppressor gene, which means its normal function is to regulate cell cycle progression and prevent uncontrolled cell division.
2. Recognize that the RB1 protein plays a critical role in controlling the transition from the G1 phase to the S phase of the cell cycle by inhibiting E2F transcription factors, which promote DNA replication.
3. Note that when RB1 is functioning normally, it binds to E2F and keeps it inactive, thereby preventing cells from prematurely entering the DNA synthesis phase.
4. Realize that mutations in RB1 lead to loss of this regulatory function, allowing cells to divide uncontrollably, which contributes to the development of cancers such as retinoblastoma.
5. Summarize that the normal function of RB1 is to act as a gatekeeper in the cell cycle, ensuring cells only divide when appropriate, thus maintaining genomic stability.

Key Concepts

Tumor Suppressor Genes

Tumor suppressor genes produce proteins that regulate cell growth and division, preventing uncontrolled proliferation. When these genes, like RB1, are mutated or inactivated, cells can grow uncontrollably, leading to cancer development.

Function of the RB1 Gene

The RB1 gene encodes the retinoblastoma protein (pRB), which controls the cell cycle by inhibiting progression from the G1 to S phase. It acts as a checkpoint to prevent excessive cell division, and loss of its function removes this control, promoting tumor formation.

Mechanism of Cancer Development via Gene Mutation

Mutations in genes like RB1 disrupt normal cellular functions, such as cell cycle regulation, DNA repair, or apoptosis. This disruption allows abnormal cells to survive and proliferate, contributing to cancer initiation and progression.