Control of RNA polymerase II by non-proteolytic ubiquitylation

Asr1 inactivates RNA polymerase II (pol II) via non-proteolytic ubiquitylation. We posit that the Ub-ligase Asr1 recognizes inappropriately initiated pol II complexes at subtelomeric chromatin via direct binding to the serine 5 (S5)-phosphorylated form of the pol II carboxy-terminal domain. It then oligoubiquitylates at least two subunits of pol II, resulting in ejection of the Rpb4/Rpb7 subunits and inactivation of polymerase function. Not show is the deubiquitylating enzyme Ubp3, which associates with Asr1 and inhibits this process.

© Bill Tansey 2017