UBB cDNA Clone – Ubiquitin B (Human)

This gene encodes ubiquitin, one of the most conserved proteins known. Ubiquitin has a major role in targeting cellular proteins for degradation by the 26S proteosome. It is also involved in the maintenance of chromatin structure, the regulation of gene expression, and the stress response. Ubiquitin is synthesized as a precursor protein consisting of either polyubiquitin chains or a single ubiquitin moiety fused to an unrelated protein. This gene consists of three direct repeats of the ubiquitin coding sequence with no spacer sequence. Consequently, the protein is expressed as a polyubiquitin precursor with a final amino acid after the last repeat. An aberrant form of this protein has been detected in patients with Alzheimer's disease and Down syndrome. Pseudogenes of this gene are located on chromosomes 1, 2, 13, and 17. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2013]

UBB: Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling. Belongs to the ubiquitin family.

Protein type: Cell development/differentiation; Cell cycle regulation; Ubiquitin-like modifier; Apoptosis; Transcription regulation; Motility/polarity/chemotaxis

Chromosomal Location of Human Ortholog: 17p12-p11.2

Cellular Component: cell soma; cytosol; endosome membrane; extracellular space; mitochondrion; neuron projection; nucleoplasm; nucleus; plasma membrane

Molecular Function: protein binding

Biological Process: activation of MAPK activity; activation of NF-kappaB transcription factor; anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolic process; bypass DNA synthesis; cellular protein metabolic process; DNA damage response, detection of DNA damage; DNA damage response, signal transduction by p53 class mediator resulting in cell cycle arrest; endosome transport; error-prone postreplication DNA repair; fibroblast growth factor receptor signaling pathway; G2/M transition of mitotic cell cycle; glycogen biosynthetic process; I-kappaB kinase/NF-kappaB cascade; innate immune response; JNK cascade; macroautophagy; MAPKKK cascade; mitochondrion transport along microtubule; MyD88-dependent toll-like receptor signaling pathway; MyD88-independent toll-like receptor signaling pathway; negative regulation of apoptosis; negative regulation of epidermal growth factor receptor signaling pathway; negative regulation of interferon type I production; negative regulation of transcription from RNA polymerase II promoter; negative regulation of transforming growth factor beta receptor signaling pathway; negative regulation of ubiquitin-protein ligase activity during mitotic cell cycle; neurite morphogenesis; Notch signaling pathway; nucleotide-excision repair, DNA damage recognition; nucleotide-excision repair, DNA duplex unwinding; nucleotide-excision repair, DNA gap filling; nucleotide-excision repair, DNA incision; nucleotide-excision repair, DNA incision, 5'-to lesion; nucleotide-excision repair, preincision complex assembly; positive regulation of apoptosis; positive regulation of epidermal growth factor receptor signaling pathway; positive regulation of I-kappaB kinase/NF-kappaB cascade; positive regulation of protein ubiquitination; positive regulation of transcription from RNA polymerase II promoter; positive regulation of ubiquitin-protein ligase activity during mitotic cell cycle; proteasomal ubiquitin-dependent protein catabolic process; protein polyubiquitination; protein ubiquitination during ubiquitin-dependent protein catabolic process; regulation of interferon type I production; regulation of mitochondrial membrane potential; regulation of mRNA stability; stimulatory C-type lectin receptor signaling pathway; stress-activated MAPK cascade; T cell receptor signaling pathway; transcription-coupled nucleotide-excision repair; transforming growth factor beta receptor signaling pathway; tumor necrosis factor-mediated signaling pathway; viral infectious cycle; virus assembly; Wnt receptor signaling pathway; Wnt receptor signaling pathway, planar cell polarity pathway

Disease: Cleft Palate, Isolated