It is now established that the light-harvesting chlorophyll—protein complex (LHCP) of chloroplasts becomes phosphorylated in the light. In this study subfractionation of phosphorylated intact chloroplasts has been carried out to compare the phosphorylation of LHCP in non-appressed and appressed thylakoid regions. The results show around 10-times higher relative phosphorylation in the non-appressed regions than in the appressed ones. Since the non-appressed thylakoids also contain almost all photosystem 1, this region is likely to be the site for energy transfer from LHCP to photosystem 1 under phosphorylated conditions.
