Sigma factor phosphorylation in the photosynthetic control of photosystem stoichiometry

• DOI: 10.1073/pnas.0911692107
• Publication Date: 2010-05-25T03:59:42Z
• Authors: Masanori Shimizu; Hideki Kato; Takeshi Ogawa; Aya Kurachi; Yoshiko Nakagawa; Hirokazu Kobayashi
• Keywords: Plastoquinone; Sigma factor

An imbalance in photosynthetic electron transfer is thought to be redressed by control of the rate expression genes encoding apoproteins photosystem (PS)-I and PS-II response redox state plastoquinone (PQ), which a connecting carrier. PS stoichiometry then adjusted enhance efficiency. In prokaryotes, sigma factors are well known for their participation RNA polymerase activity transcription, whereas there have been no reports concerning association with regulation. We found that phosphorylation SIG1, major factor (SIG), regulated signals selectively inhibits transcription psaA gene, encodes PS-I protein. produced transgenic Arabidopsis plants or without putative sites SIG1 demonstrated through vivo labeling Thr-170 was involved phosphorylation. analyzed vitro transcriptional responses status regard involvement site. revealed an enhanced under oxidative conditions PQ form associated molecular mass holoenzyme. Phosphorylation proved crucial change promoter specificity sustaining balanced components responsible harmonious flow maintain