hbuce-1

UBE2D4 is a member of the ubiquitin-conjugating E2 family whose members perform the second step in the ubiquitination reaction. Initially identified as the main process for protein degradation, ubiquitination is believed nowadays to be crucial for a wider range of cellular processes. The outcome of the ubiquitin-conjugation reaction, and thereby the fate of the substrate, is heavily dependent on the number of ubiquitin molecules attached and how these ubiquitin molecules are inter-connected. To deal with this complexity and to allow adequate ubiquitination in time and space, a highly sophisticated conjugation machinery has been developed. In a sequential manner, ubiquitin becomes activated by a ubiquitin-activating enzyme (E1), which then transfers the ubiquitin to a group of ubiquitin-conjugating enzymes (E2s). Next, ubiquitin-loaded E2s are interacting with ubiquitin-protein ligases (E3s) and ubiquitin is conjugated to substrates on recruitment by the E3. These three key enzymes are operating in a hierarchical system, wherein two E1s and 35 E2s have been found and hundreds of E3s have been identified in humans. It has been identified the UBE2D family (UBE2D1-4) as E2 partners for IDOL that support both autoubiquitination and IDOL-dependent ubiquitination of the LDLR in a cell-free system.

Ubiquitin-Conjugating Enzyme E2 D4 (UBE2D4) is a ligase that belongs to the Ubiquitin-Conjugating Enzyme family. UBE2D4 has been proposed to participate in Ubl conjugation pathway. UBE2D4 takes part in post-translational protein modification, protein K6-linked ubiquitination, protein K11-linked ubiquitination, protein K27-linked ubiquitination, protein K29-linked ubiquitination, protein K48-linked ubiquitination, and protein K63-linked ubiquitination. UBE2D4 regulate of protein metabolic process. UBE2D4 accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro, UBE2D4 able to promote polyubiquitination using all 7 ubiquitin Lys residues, but may prefer 'Lys-11' and 'Lys-48'-linked poly-ubiquitination.