The Emerging Roles of Human Immunity-Related GTPase M (IRGM) Gene

Abstract

Immunity-related GTPase family M (IRGM) protein, discovered for the first time in 1990, belongs to IRG family of proteins and is divided into five subfamilies (IRGA, IRGB, IRGC, IRGD and IRGM). These are responsive to interferon- and play a pivotal role in immune response to pathogens in mice. Owing to lack of interferon response element in the promoter region, human IRGM does not respond to interferon- stimulation, which is why it was earlier thought to be non-functional gene. Moreover, evolutionary history suggests that this gene was non-functional for ~25 million years ago. Bioinformatics has been instrumental in elucidating its evolutionary history as well as functions, especially in its interactions with the proteins of autophagy pathway. Recently, several studies have demonstrated the various functions of IRGM in limiting different pathogens in humans. This review discusses how and various roles played by IRGM unraveled in the recent years.