HIP2 (D27C4) Rabbit mAb #8226

Protein ubiquitination requires the concerted action of the E1, E2, and E3 ubiquitin-conjugating enzymes. Ubiquitin is first activated through ATP-dependent formation of a thiol ester with ubiquitin-activating enzyme E1. The activated ubiquitin is then transferred to a thiol group of ubiquitin-carrier enzyme E2. The final step is the transfer of ubiquitin from E2 to an ε-amino group of the target protein lysine residue, which is mediated by ubiquitin-ligase enzyme E3 (1).
Huntingtin-interacting protein-2 (HIP2), also known as E2-25K, is a member of the E2 protein family that is highly expressed in the brain and catalyzes multiubiquitin chain synthesis via Lys48 of ubiquitin (2). E2-25K is reportedly involved in Alzheimer's disease, Huntington's disease and antigen processing through its interaction with amyloid-β, huntingtin, and MHC-heavy chain proteins (3-6). Recent studies have also implicated HIP2 in the control of apoptosis and cell-cycle progression through its ability to regulate the stability of Smac/Diablo and cyclin B1 (7,8).