Protein ubiquitination and formation of polyubiquitin chains without ATP, E1 and E2 enzymes.

Protein ubiquitination and formation of polyubiquitin chains without ATP, E1 and E2 enzymes† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c4sc02340d Click here for additional data file. Click here for additional data file.

Herpes simplex virus type 1 immediate-early protein ICP0 and is isolated RING finger domain act as ubiquitin E3 ligases in vitro.

Proteasome-dependent degradation of ubiquitinated proteins plays a key role in many important cellular processes. Ubiquitination requires the E1 ubiquitin activating enzyme, an E2 ubiquitin conjugating enzyme, and frequently a substrate-specific ubiquitin protein ligase (E3). One class of E3 ubiquitin ligases has been shown to contain a common zinc-binding RING finger motif. We have previously ...

Two different classes of E2 ubiquitin-conjugating enzymes are required for the mono-ubiquitination of proteins and elongation by polyubiquitin chains with a specific topology.

RING (really interesting new gene) and U-box E3 ligases bridge E2 ubiquitin-conjugating enzymes and substrates to enable the transfer of ubiquitin to a lysine residue on the substrate or to one of the seven lysine residues of ubiquitin for polyubiquitin chain elongation. Different polyubiquitin chains have different functions. Lys(48)-linked chains target proteins for proteasomal degradation, a...

The E2 ubiquitin-conjugating enzymes direct polyubiquitination to preferred lysines.

The ubiquitin-proteasome pathway plays a crucial role in many cellular processes by degrading substrates tagged by polyubiquitin chains, linked mostly through lysine 48 of ubiquitin. Although polymerization of ubiquitin via its six other lysine residues exists in vivo as part of various physiological pathways, the molecular mechanisms that determine the type of polyubiquitin chains remained lar...

Auto-ubiquitination of Mdm2 enhances its substrate ubiquitin ligase activity.

The RING domain E3 ubiquitin ligase Mdm2 is the master regulator of the tumor suppressor p53. It targets p53 for proteasomal degradation, restraining the potent activity of p53 and enabling cell survival and proliferation. Like most E3 ligases, Mdm2 can also ubiquitinate itself. How Mdm2 auto-ubiquitination may influence its substrate ubiquitin ligase activity is undefined. Here we show that au...