The role of cation diffusion facilitator CDF-1 in lipid metabolism in Caenorhabditis elegans

Zinc is one of the most important trace elements that plays a vital role in many biological processes, and aberrant zinc metabolism has been implicated in lipid-related metabolic diseases. Previously, we showed that zinc antagonizes iron to regulate sterol regulatory element-binding proteins and stearoyl-CoA desaturase (SREBP-SCD) pathway in lipid metabolism in model organism Caenorhabditis elegans. Here, we further identified another cation diffusion facilitator CDF-1 in addition to SUR-7 in response to zinc to regulate lipid metabolism. Inactivation of SBP-1, the only homolog of SREBPs, leads to increased zinc level but decreased lipid accumulation reversely. However, either cdf-1(n2527) or sur-7(tm6523) mutation could successfully restore the altered fatty acid profile, fat content and zinc level of sbp-1(ep79) mutant. Furthermore, we found that CDF-1/SUR-7 may function bypass SBP-1 to directly affect the conversion activity of SCD in the biosynthesis of unsaturated fatty acids and lipid accumulation. Collectively, these results consistently support the link between zinc homeostasis and lipid metabolism via SREBP-SCD axis by cation diffusion facilitators CDF-1 and SUR-7.