Mammalian cysteine dioxygenase type 1 (CDO1) is an essential enzyme for taurine biosynthesis and the biodegradation of toxic cysteine. As previously suggested, Cdo1 may be a marker of liposarcoma progression and adipogenic differentiation, but the role of Cdo1 in adipogenesis has yet been reported. In this study, we found that the expression of Cdo1 is dramatically elevated during adipogenic differentiation of 3T3-L1 pre-adipocytes and mouse bone marrow-derived mesenchymal stem cells (mBMSCs). Conversely, knockdown of Cdo1 inhibited expression of adipogenic specific genes and lipid droplet formation in 3T3-L1 cells and mBMSCs. Mechanistically, we found Cdo1 interacted with Ppar gamma in response to adipogenic stimulus. Further, depletion of Cdo1 reduced the recruitment of Ppar gamma to the promoters of C/EBP alpha and Fabp4. Collectively, our finding indicates that Cdo1 may be a co-activator of Ppar gamma in adipogenesis, and may contribute to the development of disease associated with excessive adipose tissue. (C) 2015 Elsevier Inc. All rights reserved.