Figure 7.
Impact of phot1 R472H on intermolecular receptor interactions. A, immunoblot analysis of total protein extracts isolated from 3-day-old etiolated seedlings of p1-GFP, p1-GFP R472H (R472H 2), phot2-1 (p2-1), and F1 seedlings from p1-GFP × p2-1 and R472H x p2-1 crosses. Protein extracts were probed with anti-phot1 antibody (top panel) or anti-UGPase antibody as a loading control (bottom panel). B, hypocotyl curvature responses of 3-day-old etiolated seedlings for each of the different genotypes. Seedlings were irradiated with unidirectional blue light (BL) at 0.5 μmol m−2 s−1 for 24 h. Curvatures were calculated as the mean ± S.E. of 52–69 seedlings. C, transphosphorylation between phot1 R472H and phot1 in vitro. The autoradiograph shows transphosphorylation of a kinase-inactive (D806N) version of GST-phot1 (GST-KD) by phot1 or phot1 R472H in protein extracts from insect cells. Immunoblot analysis of phot1 protein levels is shown below.