Global kinome profiling reveals abnormal active kinases in human skeletal muscle from obese insulin resistant participants

<b>ABATRACT</b> <b>Context:</b> Obesity-related insulin resistance (OIR) is one of the main contributors to type 2 diabetes and other metabolic diseases. Protein kinases are implicated in key signaling steps including insulin signaling and glucose metabolism. Molecular mechanisms underlying OIR involving global active kinases remain less understood. <b>Objective: </b>To investigate abnormal active kinase responsible for OIR in human skeletal muscle. <b>Design: </b>Stable isotopic labeling-based quantitative proteomics analysis and affinity-based active enzyme probes to profile <i>in vivo</i> active kinases. <b></b> <b>Participants: </b>Eight lean control and eight OIR but non-diabetic human participants who underwent hyperinsulinemic euglycemic clamp with muscle biopsy.<b></b> <b>Results: </b>We identified the 1st active kinome comprised of 54 active protein kinases in human skeletal muscle. The activities of 23 kinases were different in OIR compared to Lean muscle (11 hyper- and 12 hypo-active), while their protein abundance was the same between the two groups. The activities of multiple kinases involved in AMPK and p38 signaling were lower in OIR compared to Lean. On the contrary, multiple kinases in JNK signaling pathway exhibited higher activity in OIR vs. Lean. The kinase-substrate-prediction based on experimental data further confirmed a potential down-regulation of insulin signaling (e.g., inhibited phosphorylation of IRS1 and AKT1/2). <b>Conclusions: </b>These findings provide a global view of the active kinome in OIR and Lean muscle, pinpoint novel specific impairment in kinase activities in multiple signaling pathways important for skeletal muscle insulin resistance and provide potential drug targets (i.e., abnormal active kinase) to prevent and/or reverse skeletal muscle insulin resistance in humans.