BACKGROUND: Mitochondrial homeostasis is vital for optimal skeletal muscle integrity. Mitochondrial quality control (MQC) mechanisms that are essential for maintaining proper functions of mitochondria include mitochondrial biogenesis, dynamics and mitophagy. Previously, Syntaxin 4 (STX4), traditionally considered a cell surface protein known for glucose uptake in skeletal muscle, was also identified at the outer mitochondrial membrane. STX4 enrichment was sufficient to reverse Type 2 diabetes-as...