Analysis of the Chloroplast Protein Kinase Stt7 during State Transitions
Figure 1
Fractionation of Stt7 and Chlorophyll-Protein Complexes by Sucrose Density Gradient Centrifugation
(A) Thylakoid membranes from Stt7-HA cells in state 1 and state 2 were solubilized with n-dodecyl-β-maltoside, and the chlorophyll-protein complexes were separated by centrifugation on a sucrose density gradient. Proteins from the fractions of the gradients corresponding to Stt7-HA were separated by SDS-PAGE. Immunoblotting was performed with the indicated antibodies; α-P-Thr, anti–phospho-Thr. The identity of the phosphorylated proteins in the lower panel was determined by immunoblotting with antisera from the indicated proteins. In the immunoblot with a-P-Thr, signals corresponding to CP29 and Lhcbm5 are framed.
(B) Immunoblots prepared as in (A) except that the thylakoid membranes from stt7 were used. P11/13 and P17 are the major LHCII proteins of C. reinhardtii and correspond to Type I and Type III LHCII proteins, respectively.