Phosphoproteomics Profiling Reveals the Potential Regulating Targets for Intervening Muscle Softening of Shrimp L. vannamei during Refrigeration.

Herein, the phosphorylation profiles of shrimp muscle proteins after chilling storage at 4 °C for 120 h were investigated by phosphoproteomics. A total of 1255 differential abundance phosphopeptides (DAPPs), encompassing 2128 phosphorylated sites in 608 phosphoproteins, were identified, and they were dominantly enriched in ultrastructure assembly and myofilament contraction of sarcomere architecture, mTOR signaling, autophagy, and energy metabolism pathways. Meanwhile, the dephosphorylations of kinases, phosphatases, and assembly-regulating factors were revealed through SP and R/KxxS motifs. Moreover, the predominant nodes in the protein-protein interaction (PPI) network included mitogen-activated protein kinase 14, ubiquitin-ribosomal protein eL40 fusion protein, cAMP-dependent protein kinase catalytic subunit, heat shock protein, and myosin light chain kinase; meanwhile, these proteins significantly correlated with texture deterioration. Subsequently, the associated protein MAPK was verified by Western blotting. Collectively, this study deciphered the undefined mechanisms governing muscle softening of L. vannamei during refrigeration from a phosphoproteomics perspective and provided valuable targets against softening.