Organization and Chromosomal Mapping of Mouse Gh/Tissue Transglutaminase Gene (Tgm2)

The mouse Gh/tissue transglutaminase gene (Tgm2), coding a dual-function protein that both binds guanosine triphosphate (GTP) and catalyzes the posttranslational modification of proteins by transamidation of glutamine residues, has been cloned. Sequence analysis ofTgm2and comparison with the TGase sequences of other species allowed correction of several apparent sequencing artifacts in theTgm2cDNA.Tgm2spans approximately 34 kb and has 13 exons and 12 introns. Although the structure ofTgm2shows similarity to that of other transglutaminase genes, with introns ranging from 921 bp to >5 kb, several introns differ considerably in size from those of the human Ghgene,TGM2. Tgm2maps to the distal region of mouse chromosome 2, a region syntenic to human chromosome 20q containing TGM2.Tgm2is in the vicinity of two uncloned mouse mutations, diminutive (dm) and blind-sterile (bs). Genomic DNA fromdmmice was unavailable; however, Southern blot analysis ofbsDNA showed no gross rearrangements ofTgm2.