Figure 7.

Time-course analysis of LeMPK1, 2, and 3 activity induced by UV-B. A, L. peruvianum cells were left untreated (Unt) or were irradiated for 5 min with UV-B. At the times indicated, samples were quick-frozen and assayed for MAPK activity in immunocomplex kinase assays with anti-LeMPK1, 2, and 3 antisera (MPK1, 2, and 3) as described in Figure 6. A representative experiment is shown; the exact timing and magnitude of the response varied slightly among different experiments. B, To demonstrate specificity of the anti-LeMPK3 antiserum, antiserum was preincubated with an excess of competitor peptides and was thereafter incubated with extract derived from the 10-min UV-B sample shown in A.