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The Scientific World Journal
Volume 2014, Article ID 714561, 13 pages
Review Article

Biological Functionalities of Transglutaminase 2 and the Possibility of Its Compensation by Other Members of the Transglutaminase Family

Biomedical Research Group, Department of Life Sciences, Faculty of Science & Technology, Anglia Ruskin University, East Road, Cambridge, CB1 1PT, UK

Received 2 October 2013; Accepted 30 October 2013; Published 23 March 2014

Academic Editors: B. Poulain, M. Shimaoka, and M. M. M. Wilhelmus

Copyright © 2014 Benedict Onyekachi Odii and Peter Coussons. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Transglutaminase 2 (TG2) is the most widely distributed and most abundantly expressed member of the transglutaminase family of enzymes, a group of intracellular and extracellular proteins that catalyze the Ca2+-dependent posttranslational modification of proteins. It is a unique member of the transglutaminase family owing to its specialized biochemical, structural and functional elements, ubiquitous tissue distribution and subcellular localization, and substrate specificity. The broad substrate specificity of TG2 and its flexible interaction with numerous other gene products may account for its multiple biological functions. In addition to the classic Ca2+-dependent transamidation of proteins, which is a hallmark of transglutaminase enzymes, additional Ca2+-independent enzymatic and nonenzymatic activities of TG2 have been identified. Many such activities have been directly or indirectly implicated in diverse cellular physiological events, including cell growth and differentiation, cell adhesion and morphology, extracellular matrix stabilization, wound healing, cellular development, receptor-mediated endocytosis, apoptosis, and disease pathology. Given the wide range of activities of the transglutaminase gene family it has been suggested that, in the absence of active versions of TG2, its function could be compensated for by other members of the transglutaminase family. It is in the light of this assertion that we review, herein, TG2 activities and the possibilities and premises for compensation for its absence.