Ube2N, a member of the E2 Ubiquitin-conjugating enzyme family, completes the second step of ubiquitination reactions, essentially targeting proteins for proteasomic degradation. When proteins are modified with ubiquitin in an important cellular mechanism targeting abnormal or short lived proteins, ubiquitin, a short protein of 76 amino acids, attaches to a lysine residue resting on the target protein. Multiple cycles of ubiquitination create a polyubiquitin chain that the proteasome recognizes and subsequently triggers the ATP-dependent unfolding of the target protein. This allows protoeolytic degradation of the target protein. These degradation products are highly expressed in heart and skeletal muscles. Ube2N moderates the transcriptional activation of target genes, affects the progress of cell differentiation and aging, and also influences the DNA repair pathway, further adding to the survival of cells after DNA damage.
