UNIGE document Scientific Article
previous document  unige:77952  next document
add to browser collection

Analysis of the Chloroplast Protein Kinase Stt7 during State Transitions

Published in PLOS Biology. 2009, vol. 7, no. 3, p. 0664-0675
Abstract State transitions allow for the balancing of the light excitation energy between photosystem I and photosystem II and for optimal photosynthetic activity when photosynthetic organisms are subjected to changing light conditions. This process is regulated by the redox state of the plastoquinone pool through the Stt7/STN7 protein kinase required for phosphorylation of the light-harvesting complex LHCII and for the reversible displacement of the mobile LHCII between the photosystems. We show that Stt7 is associated with photosynthetic complexes including LHCII, photosystem I, and the cytochrome b6f complex. Our data reveal that Stt7 acts in catalytic amounts. We also provide evidence that Stt7 contains a transmembrane region that separates its catalytic kinase domain on the stromal side from its N-terminal end in the thylakoid lumen with two conserved Cys that are critical for its activity and state transitions. On the basis of these data, we propose that the activity of Stt7 is regulated through its transmembrane domain and that a disulfide bond between the two lumen Cys is essential for its activity. The high-light–induced reduction of this bond may occur through a transthylakoid thiol–reducing pathway driven by the ferredoxin-thioredoxin system which is also required for cytochrome b6f assembly and heme biogenesis.
Full text
(ISO format)
LEMEILLE, Sylvain et al. Analysis of the Chloroplast Protein Kinase Stt7 during State Transitions. In: PLOS Biology, 2009, vol. 7, n° 3, p. 0664-0675. doi: 10.1371/journal.pbio.1000045 https://archive-ouverte.unige.ch/unige:77952

352 hits



Deposited on : 2015-12-01

Export document
Format :
Citation style :