Non-Lethal heat shock induces COMMD gene activation and enhances pathogen defense in Procambarus clarkii

The COMMD (copper metabolism MURR1 domain-containing) protein family, characterized by a conserved COMM domain, plays crucial roles in metal ion transport and NF-κB signaling regulation in vertebrates. However, its functional roles in invertebrates, particularly crustaceans, remain poorly understood. This study aimed to identify and characterize COMMD family genes in red swamp crayfish (Procambarus clarkii) and to investigate their involvement in immune responses under environmental stress.

Seven COMMD genes (COMMD2, COMMD3, COMMD4, COMMD5, COMMD7, COMMD8, and COMMD10) were identified and analyzed in P. clarkii. These genes exhibited distinct genomic structures and tissue-specific expression profiles. COMMD2, COMMD3, COMMD8, and COMMD10 were predominantly expressed in hemocytes and gills, whereas COMMD4 and COMMD7 showed higher expression in the hepatopancreas. Non-lethal heat shock (NLHS) significantly enhanced pathogen resistance in P. clarkii, which was accompanied by a rapid and strong induction of COMMD8. Transcriptome analysis and RNA interference experiments revealed that COMMD8 positively regulates the TLR/MyD88/NF-κB signaling pathway. Silencing of COMMD8 suppressed TLR1 and MyD88 expression and delayed NF-κB activation, indicating its role as a key modulator of immune signaling under stress conditions.

This study demonstrates that COMMD8 is a critical regulator of stress-induced immune responses in P. clarkii, mediating enhanced resistance through modulation of innate immune signaling. These findings offer new insights into the function of COMMD proteins in crustaceans and contribute to a better understanding of how environmental stress influences invertebrate immunity.