Figure 5. Insulin-induced phosphorylation is preserved but hypertonicity-induced glucose uptake is impaired in tankyrase-depleted adipocytes.

(A) Day 6 adipocytes were electroporated with T1A (lanes 3 and 4) or the point-mutation control Pmt (lanes 1 and 2). After insulin stimulation (20 nM for 30 min) as indicated (lanes 2 and 4) on day 8, extracts were immunoblotted for the IR, other signalling molecules as indicated, and their phosphorylated forms (30 μg protein/lane). (B) Adipocytes electroporated on day 6 with T1A (open bars) or the point-mutation control Pmt (solid bars) were assayed on day 8 for [³H]deoxy-D-glucose uptake in the basal state and after osmotic shock (600 mM sorbitol for 20 min). The average uptake of 6 wells (means±S.E.M.) is shown. This study was repeated once with similar results. ERK, extracellular-signal-regulated kinase.