1. Afadin is a scaffold protein repressing insulin action via HDAC6 in adipose tissue.
- Author
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Lundh M, Petersen PS, Isidor MS, Kazoka-Sørensen DN, Plucińska K, Shamsi F, Ørskov C, Tozzi M, Brown EL, Andersen E, Ma T, Müller U, Barrès R, Kristiansen VB, Gerhart-Hines Z, Tseng YH, and Emanuelli B
- Subjects
- 3T3-L1 Cells, Adipocytes metabolism, Adipocytes pathology, Adipose Tissue pathology, Animals, Antigens, CD metabolism, Diet, High-Fat adverse effects, Glucose metabolism, Histone Deacetylase 6 metabolism, Homeostasis genetics, Humans, Insulin metabolism, Insulin pharmacology, Insulin Resistance, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, Microfilament Proteins metabolism, Obesity etiology, Obesity metabolism, Obesity pathology, Phosphorylation, Primary Cell Culture, Receptor, Insulin metabolism, Adipose Tissue metabolism, Antigens, CD genetics, Histone Deacetylase 6 genetics, Insulin genetics, Microfilament Proteins genetics, Obesity genetics, Protein Processing, Post-Translational, Receptor, Insulin genetics
- Abstract
Insulin orchestrates metabolic homeostasis through a complex signaling network for which the precise mechanisms controlling its fine-tuning are not completely understood. Here, we report that Afadin, a scaffold protein, is phosphorylated on S1795 (S1718 in humans) in response to insulin in adipocytes, and this phosphorylation is impaired with obesity and insulin resistance. In turn, loss of Afadin enhances the response to insulin in adipose tissues via upregulation of the insulin receptor protein levels. This happens in a cell-autonomous and phosphorylation-dependent manner. Insulin-stimulated Afadin-S1795 phosphorylation modulates Afadin binding with interaction partners in adipocytes, among which HDAC6 preferentially interacts with phosphorylated Afadin and acts as a key intermediate to suppress insulin receptor protein levels. Adipose tissue-specific Afadin depletion protects against insulin resistance and improves glucose homeostasis in diet-induced obese mice, independently of adiposity. Altogether, we uncover a novel insulin-induced cellular feedback mechanism governed by the interaction of Afadin with HDAC6 to negatively control insulin action in adipocytes, which may offer new strategies to alleviate insulin resistance., (© 2019 The Authors.)
- Published
- 2019
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