FIG. 2.

Reexpression of IRS-1 in IRS-1 KO cells reconstitutes differentiation. Wild-type (WT) and IRS-1-deficient (KO) adipocytes, as well as KO cells reexpressing IRS-1 (KO + IRS-1), were either stained with oil red O (A) or prepared for Western blot analysis of several adipogenic marker proteins as shown (B) at day 6 of the differentiation protocol. (C) Adipocytes were serum starved for 16 to 18 h, after which 100 nM insulin (Ins) was added for 30 min prior to exposing cells to 2-deoxy-[³H]glucose (2-DOG) for 3 min. Data are expressed as nanomoles of glucose uptake per milligram of cell protein per minute.