FIGURE 4.

Insulin stimulates OGT activity in 3T3-L1 adipocytes. OGT was immunoprecipitated with OGT (AL28) antibody covalently attached to Sepharose A beads from ±100 nm insulin-stimulated 3T3-L1 adipocytes. The affinity bound OGT (AL28) was washed and incubated in OGT buffer containing UDP-[³H]GlcNAc and 1 mm CK2 peptide (OGT peptide substrate). The reaction was conducted at 22 °C for 30, min and radioactive [³H]GlcNAc incorporation into CK2 was measured by a scintillation counter. The graphs are an average of three experiments, and the graph represents three similar experiments on separate occasions. IB, immunoblot.