The pRB protein associated with retinoblastoma, if normal and present,

Question

Quizplus · Accepted Answer

The pRB protein is a tumor suppressor protein that plays a critical role in regulating the cell cycle. One of its functions is to prevent the cell from moving from G1 to S phase by inhibiting the activity of E2F transcription factors. When pRB is present and functional, it binds to E2F and prevents it from activating its target genes, which are required for the transition from G1 to S. Therefore, the correct answer is A: if pRB is normal and present, it prevents the cell from moving from G1 to S.

The PRB Protein Associated with Retinoblastoma, If Normal and Present