Figure 1.

MKP1 is phosphorylated in response to elf26 in vivo. A, Fourteen-day-old seedlings expressing a myc-tagged MKP1 expressed from the CaMV 35S promoter in mkp1 (Col-0) were treated with 1 µm elf26 for the times indicated. Protein extracts from treated seedlings were separated by 8% large-format (16 × 16 cm) SDS-PAGE overnight and immunoblotted with anti-myc antibody to detect myc-MKP1 (top). The membrane was stained with Coomassie Blue (CBB) as a loading control (bottom). The stippled line aligns the faster migrating forms in the untreated control lanes on each side of the loading. B, Immunoblot analysis with anti-myc antibody of protein extracts from 14-d-old transgenic seedlings treated for 20 min with 1 µm elf26. Extracts were treated with (+) or without (−) λ-phosphatase with or without the phosphatase inhibitors. Protein extracts were separated by 8% large-format (16 × 16 cm) SDS-PAGE overnight. Experiments were performed three times with similar results to those shown.