Kinome profiling reveals abnormal activity of kinases in skeletal muscle from adults with obesity and insulin resistance

<b>ABSTRACT</b><b>Context: Obesity-related insulin resistance (OIR) is one of the main contributors to type 2 diabetes and other metabolic diseases. Protein kinases are implicated in insulin signaling and glucose metabolism. Molecular mechanisms underlying OIR involving global kinase activities remain incompletely understood. Objective: To investigate abnormal kinase activity associated with OIR in human skeletal muscle. Design: Stable isotopic labeling-based quantitative proteomics combined with affinity-based active enzyme probes to profile in vivo kinase activity in skeletal muscle from lean control (Lean) and OIR participants. Participants: Eight Lean and eight OIR non-diabetic human adults who underwent hyperinsulinemic-euglycemic clamp with muscle biopsy. Results: 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 the 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). Conclusions: These findings provide a global view of the kinome activity in OIR and Lean muscle, pinpoint novel specific impairment in kinase activities in signaling pathways important for skeletal muscle insulin resistance and may provide potential drug targets (i.e., abnormal kinase activities) to prevent and/or reverse skeletal muscle insulin resistance in humans.</b><br>