The Deduced Sequence of the Novel Protransglutaminase E (TGase3) of Human and Mouse

The study focused on transglutaminase 3 (TGase3), a proenzyme involved in epidermal differentiation, including hair follicle development. Researchers deduced the complete amino acid sequences of mouse and human TGase3, finding both proteins to contain 692 amino acids with a molecular mass of about 77 kDa. Despite sharing 38-53% identity with other transglutaminases, the mouse, human, and guinea pig TGase3 showed only 50-75% identity to each other, particularly varying near the proteolytic activation site. This site, characterized by a flexible and hydrophilic region, is crucial for enzyme activation. The study suggested that cleavage at this site induces a conformational change, activating the enzyme. Additionally, TGase3 mRNA expression was regulated by calcium, indicating its role in the later stages of cell envelope formation in the epidermis and hair follicle.