Distribution of transglutaminase family members in mouse whole body sections.

Transglutaminases (TGs) comprise a protein family in which the members catalyze the formation of isopeptide bonds between glutamine and lysine residues in various proteins. Eight enzymes have been identified and designated as factor XIII (FXIII) and TG1-7. Expression studies of four major members, i.e., FXIII, TG1, TG2, and TG3, have been performed in a relatively large number of mammalian tissues in comparison with those on the other isozymes. The structural and biochemical characteristics of these individual isozymes and expression analyses of TG family in some tissue extracts have been reported, but there have been no simultaneous comparative analyses of both their mRNA and protein expression patterns in tissues distributions. Thus, we developed novel experimental systems for in situ hybridization using cryofilm attached to whole body sections of neonatal mice, thereby obtaining data regarding the tissue distributions of the major TG isozymes. In this study, we performed the first detailed comparative analysis of the mRNA and protein distribution studies of TG family members in a wide range of mouse tissues. These data will be helpful for elucidating the unknown physiological and pathological functions of TGs.