Figure 3.

The IL-3R β common subunit associates with the active form of β1 integrin. (A) Starved MO7-E cells incubated or not with 10 mM of bivalent Mn2+ cations (Mn) with (+) or without (−) IL-3 were detergent extracted. Cell extracts were IP with β1 integrin mAb or IL-3R β common antibodies and IB with IL-3R β common antibodies. (B) MO7-E cells untreated (a–c) or treated with 10 mM Mn2+ (d) were subjected to flow cytometry analysis with IL-1β mAb (a) or preimmune IgG (a–e, left curve) as negative controls, mAb BV7 (b) or mAb 12G10 (c and d). Endothelial cells were subjected to flow cytometry analysis with mAb 12G10 (e). The data expressed as relative cell number (y axis) plotted as a function of fluorescence intensity (x axis) are representative of three experiments. (C) Extracts from MO7-E cells left untreated (−) or treated with Mn2+ (+) were subjected to SDS-PAGE and IB with phospho-STAT5 antibody and STAT5A antibody. Similar results were obtained in four individual experiments.