The genetic and dietary landscape of the muscle insulin signalling network

Using mass spectrometry-based phosphoproteomics, we quantified 23,126 phosphosites in the skeletal muscle of five genetically distinct inbred mouse strains exposed to two controlled dietary environments, with and without acute insulin treatment. Almost half of the insulin-regulated phosphoproteome was altered by genetic background independently of diet, and high-fat high-sugar feeding also affected insulin signalling in a strain-dependent manner. Our data illuminated signalling network organisation principles, including the uncoupling of phosphosites targeted by the same kinase. Associating diverse signalling responses with insulin-stimulated glucose uptake uncovered regulators of muscle insulin responsiveness, including the regulatory phosphosite S469 on Pfkfb2, a key glycolytic enzyme.

本研究采用基于质谱的磷酸化蛋白质组学（mass spectrometry-based phosphoproteomics）技术，对5种遗传背景各异的近交系小鼠的骨骼肌样本进行定量分析，共定量得到23126个磷酸化位点（phosphosites）。受试小鼠被置于两种可控膳食环境中，每组环境均分别设置急性胰岛素处理与未处理两个亚组。在受胰岛素调控的磷酸化蛋白质组（phosphoproteome）中，近半数的磷酸化位点变化不受膳食因素影响，而是由遗传背景差异导致；同时，高脂高糖膳食也会以品系依赖的方式影响胰岛素信号通路。本研究的数据阐明了信号网络的组织原则，包括同一激酶所靶向的磷酸化位点之间的解偶联现象。通过将多样的信号响应与胰岛素刺激的葡萄糖摄取过程相关联，本研究鉴定出了调控骨骼肌胰岛素响应的多个因子，其中包括关键糖酵解酶Pfkfb2上的调控磷酸化位点S469。