Alexa Fluor® 488 anti-Ubiquitin Antibody, Ubiquitin, P4G7,BioLegend,838711

Ubiquitin is a small (8.5 kD) regulatory protein that is ubiquitously expressed in tissues of eukaryotic organisms. There are four genes in the human genome that produce ubiquitin; UBB, UBC, UBA52 and RPS27A. UBA52 and RPS27A genes code for a single copy of ubiquitin fused to the ribosomal proteins L40 and S27a, respectively. The UBB and UBC genes code for polyubiquitin precursor proteins.Ubiquitination is a post-translational modification where a ubiquitin subunit is attached to a protein. Addition of ubiquitin can signal for degradation via the proteasome, alter cellular location, promote or prevent protein interactions, or affect activity. Ubiquitination is carried out stepwise by ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s), respectively. The cascade results in the binding of ubiquitin to lysine residues on the protein substrate via an isopeptide bond, cysteine residues through a thioester bond, serine and threonine residues through an ester bond, or the amino group of the protein's N-terminus via a peptide bond.Proteins can be modified either by a single ubiquitin unit (monoubiquitination) or a chain of ubiquitin molecules (polyubiquitination). Proteins destined for degradation by the proteasome are usually ubiquitinated on lysine residues K48 and K29, while other polyubiquitinations (e.g. on K63, K11, K6) and monoubiquitinations may regulate processes such as endocytic trafficking, inflammation, translation and DNA repair.A frameshift mutation in ubiquitin B can result in a truncated peptide missing the C-terminal glycine. This abnormal peptide, known as UBB+1, has been shown to accumulate selectively in Alzheimer's disease and other tauopathies.