Fig. 2. Endogenously expressed SCD1 is also degraded by proteasomes. NIH 3T3-L1 cells were grown in differentiation cocktail containing methylisobutylxanthine, dexamethasone, and insulin. After 10 d, the cells were collected and subjected to (A) SDS-PAGE and immunoblot analysis using anti-SCD1 antibody, and (B) pulse-chase analysis using [³⁵S]methionine in the absence (DMSO) or presence of 50 µM MG132, as described in Fig. 1 and Materials and Methods. Proteins were immunoprecipitated by anti-SCD1 antibody and analyzed by SDS-PAGE and subsequent digital autoradiography using BAS2500. Other conditions were the same as in Fig. 1.