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Ünnep R, Zsiros O, Hörcsik Z, Markó M, Jajoo A, Kohlbrecher J, Garab G, Nagy G. Low-pH induced reversible reorganizations of chloroplast thylakoid membranes - As revealed by small-angle neutron scattering. Biochim Biophys Acta Bioenerg 2017; 1858:360-365. [PMID: 28237493 DOI: 10.1016/j.bbabio.2017.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 12/20/2022]
Abstract
Energization of thylakoid membranes brings about the acidification of the lumenal aqueous phase, which activates important regulatory mechanisms. Earlier Jajoo and coworkers (2014 FEBS Lett. 588:970) have shown that low pH in isolated plant thylakoid membranes induces changes in the excitation energy distribution between the two photosystems. In order to elucidate the structural background of these changes, we used small-angle neutron scattering on thylakoid membranes exposed to low p2H (pD) and show that gradually lowering the p2H from 8.0 to 5.0 causes small but well discernible reversible diminishment of the periodic order and the lamellar repeat distance and an increased mosaicity - similar to the effects elicited by light-induced acidification of the lumen. Our data strongly suggest that thylakoids dynamically respond to the membrane energization and actively participate in different regulatory mechanisms.
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Affiliation(s)
- Renáta Ünnep
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1121 Budapest, Hungary; Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen PSI, Switzerland
| | - Ottó Zsiros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, H-6701 Szeged, Hungary
| | - Zsolt Hörcsik
- College of Nyíregyháza, Institute of Environmental Science, H-4400 Nyíregyháza, Hungary
| | - Márton Markó
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1121 Budapest, Hungary
| | - Anjana Jajoo
- School of Life Science, Devi Ahilya University, Khandwa Road, Indore 452 001, India
| | - Joachim Kohlbrecher
- Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen PSI, Switzerland
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, H-6701 Szeged, Hungary; Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, CZ-710 0 Ostrava - Slezská Ostrava, Czech Republic.
| | - Gergely Nagy
- Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen PSI, Switzerland; Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1121 Budapest, Hungary.
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