UBA52 Antibody – Rabbit Polyclonal

Ubiquitin is a highly conserved nuclear and cytoplasmic protein that 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 encodes a fusion protein consisting of ubiquitin at the N terminus and ribosomal protein L40 at the C terminus, a C-terminal extension protein (CEP). Multiple processed pseudogenes derived from this gene are present in the genome. [provided by RefSeq, Jul 2008]

Function: 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. Ref.8 Ref.12 Ref.1560S ribosomal protein L40: component of the 60S subunit of the ribosome. Ribosomal protein L40 is essential for translation of a subset of cellular transcripts, and especially for cap-dependent translation of vesicular stomatitis virus mRNAs. Ref.8 Ref.12 Ref.15

Subunit structure: Ribosomal protein L40 is part of the 60S ribosomal subunit

By similarity. Ref.15 Ref.17

Subcellular location: Ubiquitin: Cytoplasm

By similarity. Nucleus

By similarity. 60S ribosomal protein L40: Cytoplasm

By similarity.

Miscellaneous: Ubiquitin is encoded by 4 different genes. UBA52 and RPS27A genes code for a single copy of ubiquitin fused to the ribosomal proteins L40 and S27a, respectively. UBB and UBC genes code for a polyubiquitin precursor with exact head to tail repeats, the number of repeats differ between species and strains.For a better understanding, features related to ubiquitin are only indicated for the first chain.

Sequence similarities: In the N-terminal section; belongs to the ubiquitin family.In the C-terminal section; belongs to the ribosomal protein L40e family.Contains 1 ubiquitin-like domain.

Sequence caution: The sequence AAK31162.1 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.