Mature-onset obesity and insulin resistance in mice deficient in the signaling adapter p62.
Signaling cascades that control adipogenesis are essential in the regulation of body weight and obesity. The adaptor p62 controls pathways that modulate cell differentiation. We report here that p62(-/-) mice develop mature-onset obesity, leptin resistance, as well as impaired glucose and insulin intolerance. The metabolic rate was significantly reduced in p62(-/-) nonobese mice, which displayed increased mRNA levels of PPAR-gamma and reduced levels of UCP-1 in adipose tissue. Basal activity of ERK was enhanced in fat from nonobese mutant mice. Embryo fibroblasts from p62(-/-) mice differentiated better than the wild-type controls into adipocytes, which was abrogated by pharmacological inhibition of the ERK pathway. p62 is induced during adipocyte differentiation and inhibits ERK activation by direct interaction. We propose that p62 normally antagonizes basal ERK activity and adipocyte differentiation and that its loss leads to the hyperactivation of ERK that favors adipogenesis and obesity.
SciCrunch is a data sharing and display platform. Anyone can create a custom portal where they can select searchable subsets of hundreds of data sources, brand their web pages and create their community. SciCrunch will push data updates automatically to all portals on a weekly basis. User communities can also add their own data to scicrunch, however this is not currently a free service.