Objective:This study aims to explore the role of deubiquitinating enzyme YOD1 in liver nutrient metabolism. Methods:The expression of YOD1 in the liver of HFD-fed C57BL/6 mice,db/db mice and in Hepa1-6 cells after oleic acid(OA) treatment was checked by Q-PCR. Then its tissue distribution in C57BL/6 mice and its expression under different nutritional conditions was detected by Q-PCR. The content of triglycerides in Hepa1-6 cells treated with OA was determined by TAG enzymetic kit,and lipid droplets were observed by Oil Red O staining. Moreover,the mRNA and protein levels of related genes in cells were detected by Q-PCR and Western blot. Results:After a short-term HFD-fed,the mRNA level of YOD1 in the liver decreased significantly. But compared with that of db/+ mice in control group,the expression of YOD1 was no change in db/db mice.However,its expression reduced obviously in OA-treated Hepa1-6 cells. Besides,YOD1 was mainly distributed in the liver,and we observed that fasting led to increased mRNA level of YOD1 in mice liver while YOD1 decreased notably after refeeding. Further,YOD1 overexpression remarkably ameliorated OA-induced steatosis in Hepa1-6 cells by inhibiting SREBP-1c cleavage. Conclusion:YOD1 expression is regulated by nutritional status and modulates lipid metabolism in hepatocytes by inhibiting SREBP-1c cleavage.