Thylakoid potassium channel is required for efficient photosynthesis in cyanobacteria.

Abstract : A potassium channel (SynK) of the cyanobacterium Synechocystis sp. PCC 6803, a photoheterotrophic model organism for the study of photosynthesis, has been recently identified and demonstrated to function as a potassium selective channel when expressed in a heterologous system and to be located predominantly to the thylakoid membrane in cyanobacteria. To study its physiological role, a SynK-less knockout mutant was generated and characterized. Fluorimetric experiments indicated that SynK-less cyanobacteria cannot build up a proton gradient as efficiently as WT organisms, suggesting that SynK might be involved in the regulation of the electric component of the proton motive force. Accordingly, measurements of flash-induced cytochrome b(6)f turnover and respiration pointed to a reduced generation of ΔpH and to an altered linear electron transport in mutant cells. The lack of the channel did not cause an altered membrane organization, but decreased growth and modified the photosystem II/photosystem I ratio at high light intensities because of enhanced photosensitivity. These data shed light on the function of a prokaryotic potassium channel and reports evidence, by means of a genetic approach, on the requirement of a thylakoid ion channel for optimal photosynthesis.
Type de document :
Article dans une revue
Proceedings- National Academy of Sciences Usa, 2012, 109 (27), pp.11043-8. 〈10.1073/pnas.1205960109〉
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-00735033
Contributeur : Jacqueline Martin-Laffon <>
Soumis le : mardi 25 septembre 2012 - 10:47:25
Dernière modification le : jeudi 28 juin 2018 - 09:51:53

Lien texte intégral

Identifiants

Collections

Citation

Vanessa Checchetto, Anna Segalla, Guillaume Allorent, Nicoletta La Rocca, Luigi Leanza, et al.. Thylakoid potassium channel is required for efficient photosynthesis in cyanobacteria.. Proceedings- National Academy of Sciences Usa, 2012, 109 (27), pp.11043-8. 〈10.1073/pnas.1205960109〉. 〈hal-00735033〉

Partager

Métriques

Consultations de la notice

278