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  • The BCKDH Kinase and Phosph...
    White, Phillip J.; McGarrah, Robert W.; Grimsrud, Paul A.; Tso, Shih-Chia; Yang, Wen-Hsuan; Haldeman, Jonathan M.; Grenier-Larouche, Thomas; An, Jie; Lapworth, Amanda L.; Astapova, Inna; Hannou, Sarah A.; George, Tabitha; Arlotto, Michelle; Olson, Lyra B.; Lai, Michelle; Zhang, Guo-Fang; Ilkayeva, Olga; Herman, Mark A.; Wynn, R. Max; Chuang, David T.; Newgard, Christopher B.

    Cell metabolism, 06/2018, Letnik: 27, Številka: 6
    Journal Article

    Branched-chain amino acids (BCAA) are strongly associated with dysregulated glucose and lipid metabolism, but the underlying mechanisms are poorly understood. We report that inhibition of the kinase (BDK) or overexpression of the phosphatase (PPM1K) that regulates branched-chain ketoacid dehydrogenase (BCKDH), the committed step of BCAA catabolism, lowers circulating BCAA, reduces hepatic steatosis, and improves glucose tolerance in the absence of weight loss in Zucker fatty rats. Phosphoproteomics analysis identified ATP-citrate lyase (ACL) as an alternate substrate of BDK and PPM1K. Hepatic overexpression of BDK increased ACL phosphorylation and activated de novo lipogenesis. BDK and PPM1K transcript levels were increased and repressed, respectively, in response to fructose feeding or expression of the ChREBP-β transcription factor. These studies identify BDK and PPM1K as a ChREBP-regulated node that integrates BCAA and lipid metabolism. Moreover, manipulation of the BDK:PPM1K ratio relieves key metabolic disease phenotypes in a genetic model of severe obesity. Display omitted •Lowering the BDK:PPM1K ratio improves glucose and lipid homeostasis in obese rats•ATP-citrate lyase (ACL) is an alternate BDK/PPM1K substrate•Overexpression of BDK in liver increases ACL phosphorylation and de novo lipogenesis•The ChREBP-β transcription factor increases BDK and decreases PPM1K expression Branched-chain amino acids (BCAA) are strongly associated with metabolic diseases. White et al. demonstrate that the kinase (BDK) and phosphatase (PPM1K) that regulate a rate-limiting BCAA metabolic enzyme, BCKDH, also regulate ATP-citrate lyase, a key lipogenic enzyme, thus identifying a new regulatory node that integrates BCAA and lipid metabolism.