Background
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.
