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Fine-tuned regulation of the K+ /H+ antiporter KEA3 is required to optimize photosynthesis during induction.
Wang, Caijuan; Yamamoto, Hiroshi; Narumiya, Fumika; Munekage, Yuri Nakajima; Finazzi, Giovanni; Szabo, Ildiko; Shikanai, Toshiharu.
Afiliação
  • Wang C; Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
  • Yamamoto H; Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
  • Narumiya F; CREST, Japan Science and Technology Agency, Chiyoda-ku, Tokyo, 102-0076, Japan.
  • Munekage YN; Graduate School of Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0101, Japan.
  • Finazzi G; Sakai City Institute of Public Health, Sakai, Osaka, 590-0953, Japan.
  • Szabo I; Graduate School of Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0101, Japan.
  • Shikanai T; Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sandan, Hyogo, 669-1337, Japan.
Plant J ; 89(3): 540-553, 2017 02.
Article em En | MEDLINE | ID: mdl-27783435
ABSTRACT
KEA3 is a thylakoid membrane localized K+ /H+ antiporter that regulates photosynthesis by modulating two components of proton motive force (pmf), the proton gradient (∆pH) and the electric potential (∆ψ). We identified a mutant allele of KEA3, disturbed proton gradient regulation (dpgr) based on its reduced non-photochemical quenching (NPQ) in artificial (CO2 -free with low O2 ) air. This phenotype was enhanced in the mutant backgrounds of PSI cyclic electron transport (pgr5 and crr2-1). In ambient air, reduced NPQ was observed during induction of photosynthesis in dpgr, the phenotype that was enhanced after overnight dark adaptation. In contrast, the knockout allele of kea3-1 exhibited a high-NPQ phenotype during steady state in ambient air. Consistent with this kea3-1 phenotype in ambient air, the membrane topology of KEA3 indicated a proton efflux from the thylakoid lumen to the stroma. The dpgr heterozygotes showed a semidominant and dominant phenotype in artificial and ambient air, respectively. In dpgr, the protein level of KEA3 was unaffected but the downregulation of its activity was probably disturbed. Our findings suggest that fine regulation of KEA3 activity is necessary for optimizing photosynthesis.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Tipo de estudo: Prognostic_studies Idioma: En Ano de publicação: 2017 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Tipo de estudo: Prognostic_studies Idioma: En Ano de publicação: 2017 Tipo de documento: Article