33 - Insulin Signaling in Drosophila melanogaster
Eco & Evo Biology
Insulin and IGF-1 (insulin-like growth factor 1) signaling are important pathways in both metabolism and aging. It has previously been shown that mutations in the insulin-signaling pathway can extend lifespan in model organisms, such as Drosophila melanogaster (Tatar, et. al 2001). This places great importance on studying this pathway to better understand the aging process at the molecular level. D. melanogaster are interesting in that they do not have one form of insulin like humans do, but rather they have 7 different DILPs (Drosophila insulin-like peptides) that are involved in different signaling pathways in different parts of the body. I have been studying the localization of the insulin receptor (InR) protein in D. melanogaster and have found evidence that upon binding to DILPs, the receptor is shuttled from the plasma membrane to the nucleus of the cell. It has recently been shown that IGF-1 receptor is translocated to the nucleus in mice (Sehat, et. al 2010) but has not yet been studied in D. melanogaster. The implications of this study are that insulin signaling in D. melanogaster is a very dynamic process and can provide more evidence for understanding the molecular mechanisms of aging. 1. Sehat, Bita, et al. "SUMOylation mediates the nuclear translocation and signaling of the IGF-1 receptor." Science signaling 3.108 (2010): ra10. 2. Tatar, Marc, et al. "A mutant Drosophila insulin receptor homolog that extends life-span and impairs neuroendocrine function." Science 292.5514 (2001): 107-110.