Screening and Identification of Interacting Proteins of Mitfa in Red Tilapia

Skin color variation and differentiation are bottlenecks in the aquaculture industry of red tilapia. The mitfa gene primarily regulates melanocyte survival and proliferation in fish skin pigmentation. In this study, a recombinant expression vector for Mitfa expression was successfully constructed. After induction and purification, nearly 600 mu g of Mitfa protein was purified from the fermentation supernatant. His pull-down assay, followed by LC-MS/MS analysis, revealed 10 proteins that interact with the Mitfa protein. Five of these proteins were annotated in the melanogenesis and tyrosine metabolism pathways, including Krt, Tpm, Myh, Tyr and Dct. The purified Mitfa recombinant protein was injected into red tilapia, and its activity and function were examined. The expression levels of the mitfa, tyr, tyrp1, and dct genes increased greatly in the dorsal skin after injection (p < 0.05); meanwhile, the melanin content and tyrosinase activity increased significantly (p < 0.05). These findings provide a theoretical basis for comprehending the function and regulatory mechanism of the red tilapia mitfa gene.