BACKGROUND: We previously showed that Cidec was localized on the surface of 
lipid droplets and could promote the differentiation of human adipocytes, but 
the molecular mechanism was still unknown.
METHODS & RESULTS: In this study, we first sought to identify proteins that 
interact with Cidec using yeast two-hybrid system. The results revealed that 
Cidec could directly interact with AMPKα1 subunit. We further showed that AMPKα 
levels decreased while Cidec increased during the adipogenic differentiation of 
human adipocytes. Meanwhile, we observed that the increased Cidec could reduce 
AMPKα level in adipocytes, and the downregulation of AMPKα could help to promote 
the differentiation of adipocytes. The results of co-immunoprecipitation and 
immunofluorescent proved that Cidec biochemically interacted and co-localized 
with AMPKα1, which meant Cidec was a regulator for AMPKα stability through an 
ubiquitin-proteasome pathway.
CONCLUSION: Our data suggested that Cidec could interact with and down-regulate 
AMPKα through an ubiquitin-proteasome degradation pathway, which provided a 
possible mechanism of Cidec in promoting human adipocytes differentiation.
GENERAL SIGNIFICANCE: Our work proposed a new possible mechanism for human 
adipogenesis, and also provided a potential role of AMPKα as a target in 
treating obesity or obesity-related diseases.