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The thylakoid membrane protein CGL160 supports CF1CF0 ATP synthase accumulation in Arabidopsis thaliana.

Fristedt R, Martins NF, Strenkert D, Clarke CA, Suchoszek M, Thiele W, Schöttler MA, Merchant SS - PLoS ONE (2015)

Bottom Line: Accumulation of other photosynthetic complexes is largely unaffected in cgl160 mutants, suggesting that CGL160 is a specific assembly or stability factor for the CF1CF0 complex.CGL160 is not found in the mature assembled complex but it does interact specifically with subunits of ATP synthase, predominantly those in the extrinsic CF1 sub-complex.We suggest therefore that it may facilitate the assembly of CF1 into the holocomplex.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, UCLA, Los Angeles, California, United States of America; Institute for Genomics and Proteomics UCLA, Los Angeles, California, United States of America.

ABSTRACT
The biogenesis of the major thylakoid protein complexes of the photosynthetic apparatus requires auxiliary proteins supporting individual assembly steps. Here, we identify a plant lineage specific gene, CGL160, whose homolog, atp1, co-occurs with ATP synthase subunits in an operon-like arrangement in many cyanobacteria. Arabidopsis thaliana T-DNA insertion mutants, which no longer accumulate the nucleus-encoded CGL160 protein, accumulate less than 25% of wild-type levels of the chloroplast ATP synthase. Severe cosmetic or growth phenotypes result under either short day or fluctuating light growth conditions, respectively, but this is ameliorated under long day constant light growth conditions where the growth, ATP synthase activity and photosynthetic electron transport of the mutants are less affected. Accumulation of other photosynthetic complexes is largely unaffected in cgl160 mutants, suggesting that CGL160 is a specific assembly or stability factor for the CF1CF0 complex. CGL160 is not found in the mature assembled complex but it does interact specifically with subunits of ATP synthase, predominantly those in the extrinsic CF1 sub-complex. We suggest therefore that it may facilitate the assembly of CF1 into the holocomplex.

No MeSH data available.


Related in: MedlinePlus

2D native / SDS-PAGE gel immunoblotting and crosslinking indicate interaction between CGL160 and the chloroplast ATP synthase complex.A. Blue-native gel electrophoresis analysis of thylakoidal protein complexes in wild type and mutant plants. PSII-SC photosystem II supercomplex, PSII-D photosystem II dimer, PSII-M photosystem II monomer, LHCII-T light harvesting complex II trimer. The Blue-native gel was used for immunoblotting against D1, CF1 and CGL160 antibodies as indicated. B. Solubilized and cross-linked thylakoid membranes were separated by SDS-PAGE and probed with specific antibodies against CGL160 and CF1. C. Detection of CGL160 and ATP synthase subcomplexes by immunoblot analyses of 2D BN/SDS gels as in panel A, employing antibodies specific for CGL160 and individual ATPase subunits as indicated in the figure.
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pone.0121658.g008: 2D native / SDS-PAGE gel immunoblotting and crosslinking indicate interaction between CGL160 and the chloroplast ATP synthase complex.A. Blue-native gel electrophoresis analysis of thylakoidal protein complexes in wild type and mutant plants. PSII-SC photosystem II supercomplex, PSII-D photosystem II dimer, PSII-M photosystem II monomer, LHCII-T light harvesting complex II trimer. The Blue-native gel was used for immunoblotting against D1, CF1 and CGL160 antibodies as indicated. B. Solubilized and cross-linked thylakoid membranes were separated by SDS-PAGE and probed with specific antibodies against CGL160 and CF1. C. Detection of CGL160 and ATP synthase subcomplexes by immunoblot analyses of 2D BN/SDS gels as in panel A, employing antibodies specific for CGL160 and individual ATPase subunits as indicated in the figure.

Mentions: To test if CGL160 might play a role in the expression of the six plastid-encoded subunits of chloroplast ATP synthase, we tested steady-state mRNA abundances of atpA, atpB, atpE, atpF, atpH and atpI in wild-type and cgl160-1 plants by qPCR (S2 Table). None of the mRNAs was significantly reduced, but the expression of atpE and atpH was significantly increased in cgl160-1, possibly in a feedback response to the decreased ATP synthase accumulation. Furthermore, it was recently demonstrated that translation of the major thylakoid protein complexes showed no difference between the wild type and plants lacking CGL160 [25]. To determine whether CGL160 interacts with any major complex in the thylakoid membrane, immunoblots of BN-PAGE separated thylakoid membranes from Arabidopsis were probed with the CGL160 antibody (Fig. 8A).


The thylakoid membrane protein CGL160 supports CF1CF0 ATP synthase accumulation in Arabidopsis thaliana.

Fristedt R, Martins NF, Strenkert D, Clarke CA, Suchoszek M, Thiele W, Schöttler MA, Merchant SS - PLoS ONE (2015)

2D native / SDS-PAGE gel immunoblotting and crosslinking indicate interaction between CGL160 and the chloroplast ATP synthase complex.A. Blue-native gel electrophoresis analysis of thylakoidal protein complexes in wild type and mutant plants. PSII-SC photosystem II supercomplex, PSII-D photosystem II dimer, PSII-M photosystem II monomer, LHCII-T light harvesting complex II trimer. The Blue-native gel was used for immunoblotting against D1, CF1 and CGL160 antibodies as indicated. B. Solubilized and cross-linked thylakoid membranes were separated by SDS-PAGE and probed with specific antibodies against CGL160 and CF1. C. Detection of CGL160 and ATP synthase subcomplexes by immunoblot analyses of 2D BN/SDS gels as in panel A, employing antibodies specific for CGL160 and individual ATPase subunits as indicated in the figure.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4383579&req=5

pone.0121658.g008: 2D native / SDS-PAGE gel immunoblotting and crosslinking indicate interaction between CGL160 and the chloroplast ATP synthase complex.A. Blue-native gel electrophoresis analysis of thylakoidal protein complexes in wild type and mutant plants. PSII-SC photosystem II supercomplex, PSII-D photosystem II dimer, PSII-M photosystem II monomer, LHCII-T light harvesting complex II trimer. The Blue-native gel was used for immunoblotting against D1, CF1 and CGL160 antibodies as indicated. B. Solubilized and cross-linked thylakoid membranes were separated by SDS-PAGE and probed with specific antibodies against CGL160 and CF1. C. Detection of CGL160 and ATP synthase subcomplexes by immunoblot analyses of 2D BN/SDS gels as in panel A, employing antibodies specific for CGL160 and individual ATPase subunits as indicated in the figure.
Mentions: To test if CGL160 might play a role in the expression of the six plastid-encoded subunits of chloroplast ATP synthase, we tested steady-state mRNA abundances of atpA, atpB, atpE, atpF, atpH and atpI in wild-type and cgl160-1 plants by qPCR (S2 Table). None of the mRNAs was significantly reduced, but the expression of atpE and atpH was significantly increased in cgl160-1, possibly in a feedback response to the decreased ATP synthase accumulation. Furthermore, it was recently demonstrated that translation of the major thylakoid protein complexes showed no difference between the wild type and plants lacking CGL160 [25]. To determine whether CGL160 interacts with any major complex in the thylakoid membrane, immunoblots of BN-PAGE separated thylakoid membranes from Arabidopsis were probed with the CGL160 antibody (Fig. 8A).

Bottom Line: Accumulation of other photosynthetic complexes is largely unaffected in cgl160 mutants, suggesting that CGL160 is a specific assembly or stability factor for the CF1CF0 complex.CGL160 is not found in the mature assembled complex but it does interact specifically with subunits of ATP synthase, predominantly those in the extrinsic CF1 sub-complex.We suggest therefore that it may facilitate the assembly of CF1 into the holocomplex.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, UCLA, Los Angeles, California, United States of America; Institute for Genomics and Proteomics UCLA, Los Angeles, California, United States of America.

ABSTRACT
The biogenesis of the major thylakoid protein complexes of the photosynthetic apparatus requires auxiliary proteins supporting individual assembly steps. Here, we identify a plant lineage specific gene, CGL160, whose homolog, atp1, co-occurs with ATP synthase subunits in an operon-like arrangement in many cyanobacteria. Arabidopsis thaliana T-DNA insertion mutants, which no longer accumulate the nucleus-encoded CGL160 protein, accumulate less than 25% of wild-type levels of the chloroplast ATP synthase. Severe cosmetic or growth phenotypes result under either short day or fluctuating light growth conditions, respectively, but this is ameliorated under long day constant light growth conditions where the growth, ATP synthase activity and photosynthetic electron transport of the mutants are less affected. Accumulation of other photosynthetic complexes is largely unaffected in cgl160 mutants, suggesting that CGL160 is a specific assembly or stability factor for the CF1CF0 complex. CGL160 is not found in the mature assembled complex but it does interact specifically with subunits of ATP synthase, predominantly those in the extrinsic CF1 sub-complex. We suggest therefore that it may facilitate the assembly of CF1 into the holocomplex.

No MeSH data available.


Related in: MedlinePlus