Figure 2.

LHCII cycle during state transitions. Under state 1 conditions PSII and LHCII form megacomplexes within the thylakoid grana. Upon phosphorylation of the major LHCII by the Stt7 kinase, the megacomplex dissociates into PSII-LHCII supercomplexes. After further phosphorylation of the minor monomeric LHCII (CP26 and CP29) and of PSII core proteins possibly mediated by the Stl1 kinase, phosphorylated LHCII is released from PSII and migrates to the stroma region of the thylakoids where it associates with PSI (state 2; see Minagawa, 2010). Upon deactivation of the STN7 kinase, LHCII is dephosphorylated by the PPH1 phosphatase and released from PSI, it then migrates back to PSII in the grana region.