| First Author | Goodwin RL | Year | 1997 |
| Journal | Mol Biol Evol | Volume | 14 |
| Issue | 4 | Pages | 420-7 |
| PubMed ID | 9100372 | Mgi Jnum | J:39348 |
| Mgi Id | MGI:86731 | Doi | 10.1093/oxfordjournals.molbev.a025778 |
| Citation | Goodwin RL, et al. (1997) Expression of the alpha 1-proteinase inhibitor gene family during evolution of the genus Mus. Mol Biol Evol 14(4):420-7 |
| abstractText | alpha(1)-Proteinase inhibitors (alpha(1)-PIs) are members of the serpin superfamily of proteinase inhibitors, and are important in the maintenance of homeostasis in a wide variety of animal taxa. Previous studies have shown that in mice (genus Mus), evolution of alpha(1)-PIs is characterized by gene amplification, region-specific concerted evolution, and rapid accumulation of amino acid substitutions. The latter occurs primarily in the reactive center, which is the region of the alpha(1)-PI molecule that determines the inhibitor's specificity for target proteinases. The P1 residue within the reactive center, which is methionine in so-called orthodox alpha(1)-PIs and an amino acid other than methionine in unorthodox alpha(1)- PIs, is a primary determinant of inhibitor specificity. In the present study, we find that the expression of mRNAs encoding unorthodox alpha(1)-PIs is polymorphic within Mus species, i.e., among individuals or inbred strains. This is in striking contrast to mRNAs that encode orthodox alpha(1)-PIs, whose concentrations are relatively invariant. The intraspecies variations in mRNA expression represent polymorphisms in the structure of the alpha(1)- PI gene family. The results, taken together with previously described aspects of alpha(1)-PI evolution, indicate that the dissimilar levels of polymorphism exhibited by orthodox and unorthodox alpha(1)-PIs, which likely have distinct physiological functions, may reflect different levels of selective constraint. The significance of this finding to the evolution of gene families is discussed. |
