Organization and chromosomal mapping of mouse G(h)/T tissue transglutaminase gene (Tgm2)

The mouse G(h)/tissue transglutaminase gene (Tgm2), coding a dual-function protein that both binds guanosine triphosphate (GTP) and catalyzes the post translational modification of proteins by transamidation of glutamine resid ues, has been cloned. Sequence analysis of Tgm2 and comparison with the TGa se sequences of other species allowed correction of several apparent sequen cing artifacts in the Tgm2 cDNA. Tgm2 spans approximately 34 kb and has 13 exons and 12 introns. Although the structure of Tgm2 shows similarity to th at of other transglutaminase genes, with introns ranging from 921 bp to >5 kb, several introns differ considerably in size from those of the human G(h ) gene, TGM2. Tgm2 maps to the distal region of mouse chromosome 2, a regio n syntenic to human chromo some 20q containing TGM2. Tgm2 is in the vicinit y of two uncloned mouse mutations, diminutive (dm) and blind-sterile (bs). Genomic DNA from dm mice was unavailable; however. Southern blot analysis o f bs DNA showed no gross rearrangements of Tgm2. (C) 1999 Academic Press.