PPAR?-K107 SUMOylation regulates insulin sensitivity but not adiposity in mice.

ABSTRACT: The nuclear receptor peroxisome proliferator-activated receptor ? (PPAR?) is a master regulator of adipocyte differentiation and is the target for the insulin-sensitizing thiazolidinedione (TZD) drugs used to treat type 2 diabetes. In cell-based in vitro studies, the transcriptional activity of PPAR? is inhibited by covalent attachment of small ubiquitin-related modifier (SUMOylation) at K107 in its N terminus. However, whether this posttranslational modification is relevant in vivo remains unclear. Here, using mice homozygous for a mutation (K107R) that prevents SUMOylation at this position, we demonstrate that PPAR? is SUMOylated at K107 in white adipose tissue. We further show that in the context of diet-induced obesity PPAR?-K107R-mutant mice have enhanced insulin sensitivity without the corresponding increase in adiposity that typically accompanies PPAR? activation by TZDs. Accordingly, the PPAR?-K107R mutation was weaker than TZD treatment in stimulating adipocyte differentiation in vitro. Moreover, we found that both the basal and TZD-dependent transcriptomes of inguinal and epididymal white adipose tissue depots were markedly altered in the K107R-mutant mice. We conclude that PPAR? SUMOylation at K107 is physiologically relevant and may serve as a pharmacologic target for uncoupling PPAR?'s beneficial insulin-sensitizing effect from its adverse effect of weight gain.

SUBMITTER: Katafuchi T 

PROVIDER: S-EPMC6275522 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature