Polymorphisms in the coding and noncoding regions of murinePgk-1 alleles

The mouse X-linkedPgk-1 gene encodes phosphoglycerate kinase. When transfected into human cells, thePgk-1^b allele causes the appearance of mouse PGK-1^b enzyme activity. We describe here cloning of mousePgk-1^a, an allele ofPgk-1 which encodes an enzyme, PGK-1^a, with distinct electrophoretic mobility. We constructed recombinants between the DNA encodingPgk-1^b andPgk-1^a and transfected these constructs into human to assess the electrophoretic characteristics of each recombinant. In this way the charge variation between the two proteins was localized to exons 4 or 5. Sequencing of these exons revealed a single base-pair difference between the two alleles at codon 155, which predicts the amino acids lysine and threonine in PGK-1^b and PGK-1^a, respectively. A number of other DNA sequence polymorphisms exist betweenPgk-1^b andPgk-1^a including part of an L1 repeated element unique toPgk-1^a. This work was supported by the Medical Research Council of Canada, the National Cancer Institute of Canada, and the Deutsche Forschungsgemeinschaft, SFB 304.