Effects of muscle-specific oxidative stress on protein phosphorylation and its relationship with mitochondrial dysfunction, muscle oxidation, and apoptosis

•PM exhibited a higher global phosphorylation level than LL, regardless of aging time.•PM showed greater mitochondrial dysfunction, oxidation level, and apoptosis than LL.•12 h exhibited a lower phosphorylation level than 2 h, regardless of muscle type.•12 h showed more mitochondrial dysfunction, oxidation level, and apoptosis than 2 h.•The phosphorylation of apoptotic proteins affects the process of apoptosis. This study aimed to investigate the effects of muscle-specific oxidative stress on phosphorylation and its relationship with mitochondrial dysfunction, muscle oxidation, and apoptosis of porcine PM (psoas major) and LL (longissimus lumborum) during the first 24 h postmortem. The global phosphorylation level decreased and the mitochondrial dysfunction, oxidation level, and apoptosis increased significantly at 12 h postmortem compared with 2 h postmortem, suggesting that lower phosphorylation level was related to more mitochondrial dysfunction and apoptosis during the early postmortem, regardless of muscle type. PM exhibited a higher global phosphorylation level but showed greater mitochondrial dysfunction, oxidation level, and apoptosis than LL, regardless of aging time. The increased mitochondrial dysfunction and oxidative stress accelerated apoptosis, but their relationship with phosphorylation was different in various muscle types at different aging times. These findings provide insight regarding the roles of coordinated regulation of phosphorylation and apoptosis in development of quality of different muscles.