Heat Shock Protein 70 Attenuates Acute Stress-Induced Sarcoplasmic Reticulum Ca ²⁺ -ATPase Inactivation in Chicken Skeletal Muscle

Pale, soft, and exudative (PSE) meat is a severe quality problem in chicken production. In this study, HSP70-interacting proteins in normal and PSE-like chicken pectoralis major (PM) muscles were identified using Nano-LC-ESI-MS/MS analysis. The results showed that HSP70-interacting proteins were mostly enriched in pathways of glycolysis/gluconeogenesis, biosynthesis of amino acids, and the calcium signaling pathway (FDR <0.001). Immunoprecipitation, immunofluorescence, and molecular docking confirmed the specific interaction between HSP70 and SERCA1 in the PM muscle of broilers. Enzyme activity assays and in vitro experiments confirmed that HSP70 alleviates the heat-induced decrease in SERCA activity (P < 0.05). Overall, our study reveals that the HSP70-SERCA1 interaction in the PM muscle of broilers alleviates the decrease in SERCA activity in the sarcoplasmic reticulum (SR) of broiler skeletal muscle caused by acute stress, which may provide a further understanding of the mechanism of meat quality changes under acute stress.