Ubiquitylation of histones by Cullin-RING ligases

Abstract

The ubiquitin proteasome system serves as the primary means by which proteins are degraded within our cells. This process begins with the ubiquitylation cascade, involving a series of enzymatic reactions, that post-translationally modify proteins with ubiquitin. Ubiquitin can then form chains that are recognized by the proteasome causing substrate degradation. Ubiquitylation is carried out by 3 proteins; the activating enzyme (E1), conjugating enzyme (E2), and ubiquitin ligase (E3). A wide variety of E3s are present in cells, each recognizing different substrate proteins.