Biology:Ubiquitin B

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A representation of the 3D structure of the protein myoglobin showing turquoise α-helices.
Generic protein structure example

Ubiquitin is a protein that in humans is encoded by the UBB gene.[1]

Function

Ubiquitin is one of the most conserved proteins known in eukaryotic organisms. Ubiquitin is required for ATP-dependent, non-lysosomal intracellular protein degradation of abnormal proteins and normal proteins with a rapid turnover. Ubiquitin is covalently bound to proteins to be degraded, and presumably labels these proteins for degradation. Ubiquitin also binds to histone H2A in actively transcribed regions but does not cause histone H2A degradation, suggesting that ubiquitin is also involved in regulation of gene expression. 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. Aberrant form of this protein (UBB+1) has been noticed in patients with Alzheimer's disease, Down syndrome, other tauopathies (e.g. Pick's disease) and polyglutamine disease (e.g. Huntington's disease).[2][3]

References

  1. "Localization of the human UbB polyubiquitin gene to chromosome band 17p11.1-17p12". Am J Hum Genet 46 (2): 308–15. Mar 1990. PMID 2154095. 
  2. "Disease-specific accumulation of mutant ubiquitin as a marker for proteasomal dysfunction in the brain". FASEB J 17 (14): 2014–2024. Nov 2003. doi:10.1096/fj.03-0205com. PMID 14597671. 
  3. "Entrez Gene: UBB ubiquitin B". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=7314. 

Further reading