Structural and functional changes of PSI-LHCI supercomplexes of Chlamydomonas reinhardtii cells grown under high salt conditions

Rajagopal Subramanyam, Craig Jolley, Balakumar Thangaraj, Sreedhar Nellaepalli, Andrew N. Webber, Petra Fromme

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The effect of high salt concentration (100 mM NaCl) on the organization of photosystem I-light harvesting complex I supercomplexes (PSI-LHCI) of Chlamydomonas reinhardtii was studied. The electron transfer activity was reduced by 39% in isolated PSI-LHCI supercomplexes. The visible circular dichroism (CD) spectra associated with strongly coupled chlorophyll (Chl) dimers were reduced in intensity, indicating that pigment-pigment interactions were disrupted. This data is consistent with results from fluorescence streak camera spectroscopy, which suggest that red-shifted pigments in the PSI-LHCI antenna had been lost. Denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI reaction center proteins PsaD, PsaE and PsaF were reduced due to salt stress. PsaE is almost completely absent under high salt conditions. It is known that the membrane-extrinsic subunits PsaD and E form the ferredoxin-docking site. Our results indicate that the PSI-LHCI supercomplex is damaged by reactive oxygen species at high salt concentration, with particular impact on the ferredoxin-docking site and the PSI-LHCI interface.

Original languageEnglish
Pages (from-to)913-922
Number of pages10
JournalPlanta
Volume231
Issue number4
DOIs
Publication statusPublished - Mar 2010

Fingerprint

Photosystem I Protein Complex
Chlamydomonas reinhardtii
light harvesting complex
photosystem I
Salts
salts
Light
Ferredoxins
ferredoxins
pigments
salt concentration
cells
circular dichroism spectroscopy
Chlorophyll
Circular Dichroism
cameras
antennae
gel electrophoresis
electron transfer
salt stress

Keywords

  • Chlamydomonas
  • Excitation energy
  • Light harvesting complexes
  • Photosystem I core
  • PSI-LHCI supercomplexes
  • Reactive oxygen species
  • Salt stress
  • Superoxide dismutase

ASJC Scopus subject areas

  • Plant Science
  • Genetics

Cite this

Structural and functional changes of PSI-LHCI supercomplexes of Chlamydomonas reinhardtii cells grown under high salt conditions. / Subramanyam, Rajagopal; Jolley, Craig; Thangaraj, Balakumar; Nellaepalli, Sreedhar; Webber, Andrew N.; Fromme, Petra.

In: Planta, Vol. 231, No. 4, 03.2010, p. 913-922.

Research output: Contribution to journalArticle

Subramanyam, Rajagopal ; Jolley, Craig ; Thangaraj, Balakumar ; Nellaepalli, Sreedhar ; Webber, Andrew N. ; Fromme, Petra. / Structural and functional changes of PSI-LHCI supercomplexes of Chlamydomonas reinhardtii cells grown under high salt conditions. In: Planta. 2010 ; Vol. 231, No. 4. pp. 913-922.
@article{1920de6d0ba54ef8bfc54a3c283fd330,
title = "Structural and functional changes of PSI-LHCI supercomplexes of Chlamydomonas reinhardtii cells grown under high salt conditions",
abstract = "The effect of high salt concentration (100 mM NaCl) on the organization of photosystem I-light harvesting complex I supercomplexes (PSI-LHCI) of Chlamydomonas reinhardtii was studied. The electron transfer activity was reduced by 39{\%} in isolated PSI-LHCI supercomplexes. The visible circular dichroism (CD) spectra associated with strongly coupled chlorophyll (Chl) dimers were reduced in intensity, indicating that pigment-pigment interactions were disrupted. This data is consistent with results from fluorescence streak camera spectroscopy, which suggest that red-shifted pigments in the PSI-LHCI antenna had been lost. Denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI reaction center proteins PsaD, PsaE and PsaF were reduced due to salt stress. PsaE is almost completely absent under high salt conditions. It is known that the membrane-extrinsic subunits PsaD and E form the ferredoxin-docking site. Our results indicate that the PSI-LHCI supercomplex is damaged by reactive oxygen species at high salt concentration, with particular impact on the ferredoxin-docking site and the PSI-LHCI interface.",
keywords = "Chlamydomonas, Excitation energy, Light harvesting complexes, Photosystem I core, PSI-LHCI supercomplexes, Reactive oxygen species, Salt stress, Superoxide dismutase",
author = "Rajagopal Subramanyam and Craig Jolley and Balakumar Thangaraj and Sreedhar Nellaepalli and Webber, {Andrew N.} and Petra Fromme",
year = "2010",
month = "3",
doi = "10.1007/s00425-009-1097-x",
language = "English",
volume = "231",
pages = "913--922",
journal = "Planta",
issn = "0032-0935",
publisher = "Springer Verlag",
number = "4",

}

TY - JOUR

T1 - Structural and functional changes of PSI-LHCI supercomplexes of Chlamydomonas reinhardtii cells grown under high salt conditions

AU - Subramanyam, Rajagopal

AU - Jolley, Craig

AU - Thangaraj, Balakumar

AU - Nellaepalli, Sreedhar

AU - Webber, Andrew N.

AU - Fromme, Petra

PY - 2010/3

Y1 - 2010/3

N2 - The effect of high salt concentration (100 mM NaCl) on the organization of photosystem I-light harvesting complex I supercomplexes (PSI-LHCI) of Chlamydomonas reinhardtii was studied. The electron transfer activity was reduced by 39% in isolated PSI-LHCI supercomplexes. The visible circular dichroism (CD) spectra associated with strongly coupled chlorophyll (Chl) dimers were reduced in intensity, indicating that pigment-pigment interactions were disrupted. This data is consistent with results from fluorescence streak camera spectroscopy, which suggest that red-shifted pigments in the PSI-LHCI antenna had been lost. Denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI reaction center proteins PsaD, PsaE and PsaF were reduced due to salt stress. PsaE is almost completely absent under high salt conditions. It is known that the membrane-extrinsic subunits PsaD and E form the ferredoxin-docking site. Our results indicate that the PSI-LHCI supercomplex is damaged by reactive oxygen species at high salt concentration, with particular impact on the ferredoxin-docking site and the PSI-LHCI interface.

AB - The effect of high salt concentration (100 mM NaCl) on the organization of photosystem I-light harvesting complex I supercomplexes (PSI-LHCI) of Chlamydomonas reinhardtii was studied. The electron transfer activity was reduced by 39% in isolated PSI-LHCI supercomplexes. The visible circular dichroism (CD) spectra associated with strongly coupled chlorophyll (Chl) dimers were reduced in intensity, indicating that pigment-pigment interactions were disrupted. This data is consistent with results from fluorescence streak camera spectroscopy, which suggest that red-shifted pigments in the PSI-LHCI antenna had been lost. Denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI reaction center proteins PsaD, PsaE and PsaF were reduced due to salt stress. PsaE is almost completely absent under high salt conditions. It is known that the membrane-extrinsic subunits PsaD and E form the ferredoxin-docking site. Our results indicate that the PSI-LHCI supercomplex is damaged by reactive oxygen species at high salt concentration, with particular impact on the ferredoxin-docking site and the PSI-LHCI interface.

KW - Chlamydomonas

KW - Excitation energy

KW - Light harvesting complexes

KW - Photosystem I core

KW - PSI-LHCI supercomplexes

KW - Reactive oxygen species

KW - Salt stress

KW - Superoxide dismutase

UR - http://www.scopus.com/inward/record.url?scp=77950539802&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77950539802&partnerID=8YFLogxK

U2 - 10.1007/s00425-009-1097-x

DO - 10.1007/s00425-009-1097-x

M3 - Article

VL - 231

SP - 913

EP - 922

JO - Planta

JF - Planta

SN - 0032-0935

IS - 4

ER -