| First Author | Kandil E | Year | 1997 |
| Journal | Immunogenetics | Volume | 46 |
| Issue | 4 | Pages | 337-44 |
| PubMed ID | 9218537 | Mgi Jnum | J:42267 |
| Mgi Id | MGI:1095461 | Doi | 10.1007/s002510050281 |
| Citation | Kandil E, et al. (1997) PA28 subunits of the mouse proteasome: primary structures and chromosomal localization of the genes. Immunogenetics 46(4):337-44 |
| abstractText | The 20S proteasome is a multi-subunit protease responsible for the production of peptides presented by major histocompatibility complex (MHC) class I molecules. Recent evidence indicates that an interferon-gamma (IFN-gamma)- inducible PA28 activator complex enhances the generation of class I binding peptides by altering the cleavage pattern of the proteasome. In the present study, we determined the primary structures of the mouse PA28 alpha- and beta-subunits. The deduced amino acid sequences of the alpha- and beta-subunits were 49% identical. We also determined the primary structure of the mouse PA28 gamma- subunit (Ki antigen), a protein of unknown function structurally related to the alpha- and beta-subunits. The amino acid sequence identity of the gamma-subunit to the alpha- and beta-subunits was 40% and 32%, respectively. Interspecific backcross mapping showed that the mouse genes coding for the alpha- and beta-subunits (designated Pslne1 and Psme2, respectively) are tightly linked and map close to the Atp5g1 locus on chromosome 14. Thus, unlike the LMP2 and LMP7 subunits, the IFN-gamma-inducible subunits of PA28 are encoded outside the MHC. The gene coding for the gamma-subunit (designated Psme3) was mapped to the vicinity of the Brca1 locus on chromosome 11. A computer search of the DNA databases identified a gamma- subunit-like protein in ticks and Caenorhabditis elegans, the organisms with no adaptive immune system. It appears that the IFN-gamma-inducible alpha- and beta-subunits emerged by gene duplication from a gamma-subunit-like precursor. |
