Rabbit Anti-Human Ubiquitin B monoclonal antibody for ChIP, ICC, IF, WB. Ubiquitin is a conserved 76 amino acid polypeptide and can affect proteasomal degradation of the protein it is bound to, or mediate interactions with other proteins related to posttranslation modifications. The degradation of cellular regulatory proteins by the ubiquitin pathway is important as it controls the cellular growth and proliferation. Ubiquitin dependent proteolysis occurs after a covalent attachment of the peptide to a lysine residue of a protein, which involves three enzymatic reactions: E1, E2 and E3. First reaction involves ubiquitin-activating enzyme. The third reaction uses enzyme ubiquitin ligase (E3) to transfer the activated ubiquitin from E2 to a lysine residue on a protein, or directly transfers the ubiquitin from E2 to the substrate.