Association of Psb28 and Psb27 proteins with PSII-PSI supercomplexes upon exposure of Synechocystis sp. PCC 6803 to high light
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Formation of the multi-subunit oxygen-evolving Photosystem II (PSII) complex involves
a number of auxiliary protein factors. In this study we compared the location and possible
function of two homologous PSII assembly factors, Psb28-1 and Psb28-2, from the
cyanobacterium Synechocystis sp. PCC 6803. We show that FLAG-tagged Psb28-2 is
present in both the monomeric PSII core complex and a PSII core complex lacking the
inner antenna CP43 (RC47) whereas Psb28-1 preferentially binds to RC47. When cells
are exposed to increased irradiance, both tagged Psb28 proteins now associate with
oligomeric forms of PSII and with PSII-PSI supercomplexes composed of trimeric
Photosystem I (PSI) and two PSII monomers as deduced from negative stain electron
microscopy. The presence of the Psb27 accessory protein in these complexes suggests the
involvement of PSI in PSII biogenesis, possibly by photoprotecting PSII through energy
spillover. Under standard cultivation conditions the distribution of PSII complexes is
similar in WT and each of the single psb28 null mutants except for loss of RC47 in the
absence of Psb28-1. In comparison with WT, growth of mutants lacking Psb28-1 and
Psb27, but not Psb28-2, was retarded under high-light and, especially, intermittent highlight-dark
conditions, emphasizing the physiological importance of PSII assembly factors
for light acclimation.
a number of auxiliary protein factors. In this study we compared the location and possible
function of two homologous PSII assembly factors, Psb28-1 and Psb28-2, from the
cyanobacterium Synechocystis sp. PCC 6803. We show that FLAG-tagged Psb28-2 is
present in both the monomeric PSII core complex and a PSII core complex lacking the
inner antenna CP43 (RC47) whereas Psb28-1 preferentially binds to RC47. When cells
are exposed to increased irradiance, both tagged Psb28 proteins now associate with
oligomeric forms of PSII and with PSII-PSI supercomplexes composed of trimeric
Photosystem I (PSI) and two PSII monomers as deduced from negative stain electron
microscopy. The presence of the Psb27 accessory protein in these complexes suggests the
involvement of PSI in PSII biogenesis, possibly by photoprotecting PSII through energy
spillover. Under standard cultivation conditions the distribution of PSII complexes is
similar in WT and each of the single psb28 null mutants except for loss of RC47 in the
absence of Psb28-1. In comparison with WT, growth of mutants lacking Psb28-1 and
Psb27, but not Psb28-2, was retarded under high-light and, especially, intermittent highlight-dark
conditions, emphasizing the physiological importance of PSII assembly factors
for light acclimation.
Date Issued
2016-08-12
Date Acceptance
2016-08-05
Citation
Molecular Plant, 2016, 10 (1), pp.62-72
ISSN
1752-9867
Publisher
Oxford University Press (OUP)
Start Page
62
End Page
72
Journal / Book Title
Molecular Plant
Volume
10
Issue
1
Copyright Statement
© The Author 2016. Published by the Molecular Plant Shanghai Editorial Office in association with Cell Press, an imprint of Elsevier Inc., on behalf of CSPB and IPPE, SIBS, CAS. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Biotechnology and Biological Sciences Research Council (BBSRC)
Biotechnology and Biological Sciences Research Council (BBSRC)
Grant Number
BB/I00937X/1
BB/L003260/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Biochemistry & Molecular Biology
Plant Sciences
Psb28 proteins
photosystem I and II
Synechocystis
PHOTOSYSTEM-II
THERMOSYNECHOCOCCUS-ELONGATUS
CRYSTAL-STRUCTURE
SP PCC-6803
CYANOBACTERIUM
CHLOROPHYLL
RESOLUTION
COMPLEXES
ANGSTROM
REPAIR
0607 Plant Biology
Plant Biology & Botany
Publication Status
Published