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ZFIN ID: ZDB-PUB-000623-2
Identification and linkage of the proteasome activator complex PA28 subunit genes in zebrafish
Murray, B.W., Sültmann, H., and Klein, J.
Date: 2000
Source: Scandinavian journal of immunology   51(6): 571-576 (Journal)
Registered Authors: Klein, Jan, Sültmann, Holger
Keywords: none
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • Cysteine Endopeptidases/genetics*
  • Cysteine Endopeptidases/isolation & purification
  • Genetic Linkage/genetics*
  • Molecular Sequence Data
  • Multienzyme Complexes/genetics*
  • Multienzyme Complexes/isolation & purification
  • Multienzyme Complexes/metabolism
  • Multigene Family
  • Proteins/genetics*
  • Proteins/isolation & purification*
  • Proteins/metabolism
  • Sequence Alignment
  • Zebrafish
  • Zebrafish Proteins*
PubMed: 10849367 Full text @ Scand. J. Immunol.
PA28 is an activator of the latent 20S proteasome, a large multisubunit complex involved in intracellular proteolysis. Two forms of hexameric PA28 have been identified, PA28-(alphabeta)3 and PA28-(gamma)6, of which the former is of immunological importance. Both the PA28-alpha and PA28-beta subunits are inducible by interferon-gamma (IFN-gamma) and the PA28-(alphabeta)3 complex enhances the ability of the 20S proteasome to produce peptides suited for binding to major histocompatibility complex (Mhc) class I molecules. To identify the homologues of the PA28 subunits in zebrafish we screened a cDNA library and obtained full-length cDNA sequences of the genes PSME1, PSME2 and PSME3 coding for the PA28-alpha, PA28-beta and PA28-gamma subunits, respectively. Phylogenetic analysis indicates the existence of the ancestors of all three genes prior to the divergence of tetrapods and bony fishes. The IFN-gamma-inducible subunits, PA28-alpha and PA28-beta, evolve faster than the presumably older PA28-gamma subunit. Using zebrafish radiation hybrid panels, the genes PSME2 and PSME3 were mapped to linkage group 12 and shown to be separated by a distance of less than 2.4 cM. This observation suggests that an intrachromosomal duplication event created the precursor of the IFN-gamma-inducible genes from a PA28-gamma-like ancestor prior to their recruitment into the Mhc class I peptide presentation pathway.