Comparative genomic analysis of the proteasome β5t subunit gene: implications for the origin and evolution of thymoproteasomes.

ABSTRACT: The thymoproteasome is a recently discovered, specialized form of 20S proteasomes expressed exclusively in the thymic cortex. Although the precise molecular mechanism by which the thymoproteasome exerts its function remains to be elucidated, accumulating evidence indicates that it plays a crucial role in positive selection of T cells. In the present study, we analyzed the evolution of the β5t subunit, a β-type catalytic subunit uniquely present in thymoproteasomes. The gene coding for the β5t subunit, designated PSMB11, was identified in the cartilaginous fish, the most divergent group of jawed vertebrates compared to the other jawed vertebrates, but not in jawless vertebrates or invertebrates. Interestingly, teleost fish have two copies of apparently functional PSMB11 genes, designated PS

SUBMITTER: Sutoh Y 

PROVIDER: S-EPMC3805029 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature