CoIP-MS based method to identify FNIP1 binding proteins in exercising muscle

Using muscle-specific FNIP1 (WT) and FNIP1 (S220A Tg) muscle tissues, we identified approximately 600 potential FNIP1 (WT) or FNIP1 (S220A) binding proteins in exercising muscle tissue of the corresponding mice by the CoIP-MS method, proteomic analysis showed that both FNIP1 (WT) and FNIP1 (S220A) interacted with major mitochondrial proteins, such as the respiratory complex subunits. Notably, FNIP1 (S220A) specifically interacted with additional mitochondrial subunits that were not observed for FNIP1 (WT), including protein involved in NADH metabolism and sulfur cluster binding. These data suggested that non-phosphorylated FNIP1 (S220A) could enhance its interaction with mitochondria.