FIG. 6.

p38 MAPK regulates Stat1 and Stat3 DNA binding. Monocytes were either treated with 5 μM SB202190 for 30 min followed by addition of IL-13 for an additional 30 min or treated with IL-13 alone for 30 min. Nuclear proteins were extracted, and 5 μg of proteins was subjected to electrophoretic mobility shift assay analysis with ³²P-labeled Stat1- and Stat3-specific probes (A) or the OCT1 probe (Promega, Madison, Wis.) (B). In some experiments, unlabeled probe in 50-fold excess was introduced for competitive inhibition, as indicated. Arrows point to the positions of protein and DNA complexes.