GENE 540 Study Guide - Midterm Guide: Cyclin D, E2F, Tumor Suppressor Gene
Document Summary
Cdk4/cyclin d hyperphosphorylates prb; this hyperphosphorylated prb can no longer bind to. Inactivating cdk4 (kinase) to stop the prb from leaving e2f this keeps the repression going. The experiment reassures that the main function of cyclin d is to inactive prb. The results show that when you inhibit cyclin d for cells that have the rb gene, you get s-phase inhibition. This suggests that the main function of cyclin d is to inactivate prb. Dna tumor viruses express proteins that bind to the so-called pocket" region of prb to inactivate it: this leads to the uncontrolled proliferation of cells. There are no treatments to add back a tumor suppressor genes. Another approach is to inactivate cdk4 (these kinases are great targets for small molecule drugs because we know how to inhibit them) Apc = e3 ubiquitin ligase: required for cells to go from metaphase to anaphase (breaks up the anaphase inhibitor .
