PLGG1, a plastidic glycolate glycerate transporter, is required for photorespiration and defines a unique class of metabolite transporters

Photorespiratory carbon flux reaches up to a third of photosynthetic flux, thus contributes massively to the global carbon cycle. The pathway recycles glycolate-2-phosphate, the most abundant byproduct of RubisCO reactions. This oxygenation reaction of RubisCO and subsequent photorespiration significantly limit the biomass gains of many crop plants. Although photorespiration is a compartmentalized process with enzymatic reactions in the chloroplast, the peroxisomes, the mitochondria, and the cytosol, no transporter required for the core photorespiratory cycle has been identified at the molecular level to date. Using transcript coexpression analyses, we identified Plastidal glycolate glycerate translocator 1 (PLGG1) as a candidate core photorespiratory transporter. Related genes are encoded in the genomes of archaea, bacteria, fungi, and all Archaeplastida and have previously been associated with a function in programmed cell-death. A mutant deficient in PLGG1 shows WT-like growth only in an elevated carbon dioxide atmosphere. The mutant accumulates glycolate and glycerate, leading to the hypothesis that PLGG1 is a glycolate/glycerate transporter. This hypothesis was tested and supported by in vivo and in vitro transport assays and 18O2-metabolic flux profiling. Our results indicate that PLGG1 is the chloroplastidic glycolate/glycerate transporter, which is required for the function of the photorespiratory cycle. Identification of the PLGG1 transport function will facilitate unraveling the role of similar proteins in bacteria, archaea, and fungi in the future.

[1]  Barbara A Halkier,et al.  Identification of a flavin-monooxygenase as the S-oxygenating enzyme in aliphatic glucosinolate biosynthesis in Arabidopsis. , 2007, The Plant journal : for cell and molecular biology.

[2]  S. Clough,et al.  Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. , 1998, The Plant journal : for cell and molecular biology.

[3]  Junhui Wang,et al.  A chloroplast envelope membrane protein containing a putative LrgB domain related to the control of bacterial death and lysis is required for chloroplast development in Arabidopsis thaliana. , 2012, The New phytologist.

[4]  K. Howitz,et al.  d-Glycerate Transport by the Pea Chloroplast Glycolate Carrier : Studies on [1-C]d-Glycerate Uptake and d-Glycerate Dependent O(2) Evolution. , 1986, Plant physiology.

[5]  K. Howitz,et al.  Kinetic characteristics of the chloroplast envelope glycolate transporter , 1985 .

[6]  A. Weber,et al.  Dynamic Remodeling of the Plastid Envelope Membranes – A Tool for Chloroplast Envelope in vivo Localizations , 2012, Front. Plant Sci..

[7]  W. Frommer,et al.  ARAMEMNON, a Novel Database for Arabidopsis Integral Membrane Proteins1 , 2003, Plant Physiology.

[8]  A. Weber,et al.  Antisense repression reveals a crucial role of the plastidic 2-oxoglutarate/malate translocator DiT1 at the interface between carbon and nitrogen metabolism. , 2006, The Plant journal : for cell and molecular biology.

[9]  A. Weber,et al.  Plant peroxisomes respire in the light: some gaps of the photorespiratory C2 cycle have become filled--others remain. , 2006, Biochimica et biophysica acta.

[10]  C. Somerville,et al.  Photorespiration-deficient Mutants of Arabidopsis thaliana Lacking Mitochondrial Serine Transhydroxymethylase Activity. , 1981, Plant physiology.

[11]  J. Berry,et al.  Fixation of 1802 during Photorespiration , 1978 .

[12]  A. Weber,et al.  Comparative Proteomics of Chloroplast Envelopes from C3 and C4 Plants Reveals Specific Adaptations of the Plastid Envelope to C4 Photosynthesis and Candidate Proteins Required for Maintaining C4 Metabolite Fluxes1[W][OA] , 2008, Plant Physiology.

[13]  Lani F. Wu,et al.  Large-scale prediction of Saccharomyces cerevisiae gene function using overlapping transcriptional clusters , 2002, Nature Genetics.

[14]  S. Somerville,et al.  A mutant of Arabidopsis deficient in chloroplast dicarboxylate transport is missing an envelope protein , 1985 .

[15]  C. Somerville,et al.  A phosphoglycolate phosphatase-deficient mutant of Arabidopsis , 1979, Nature.

[16]  A. A. Bregman.  Laboratory investigations in cell and molecular biology , 1990 .

[17]  U. Grossniklaus,et al.  A Gateway Cloning Vector Set for High-Throughput Functional Analysis of Genes in Planta[w] , 2003, Plant Physiology.

[18]  W. Weckwerth,et al.  A Cytosolic Pathway for the Conversion of Hydroxypyruvate to Glycerate during Photorespiration in Arabidopsis[W] , 2008, The Plant Cell Online.

[19]  A. Weber,et al.  The Arabidopsis mutant dct is deficient in the plastidic glutamate/malate translocator DiT2. , 2003, The Plant journal : for cell and molecular biology.

[20]  K. Howitz,et al.  Substrate specificity of the pea chloroplast glycolate transporter , 1985 .

[21]  F. Myouga,et al.  Loss of the plastid envelope protein AtLrgB causes spontaneous chlorotic cell death in Arabidopsis thaliana. , 2012, Plant & cell physiology.

[22]  S. Somerville,et al.  An Arabidopsis thaliana mutant defective in chloroplast dicarboxylate transport. , 1983, Proceedings of the National Academy of Sciences of the United States of America.

[23]  W. Weckwerth,et al.  d-GLYCERATE 3-KINASE, the Last Unknown Enzyme in the Photorespiratory Cycle in Arabidopsis, Belongs to a Novel Kinase Family , 2005, The Plant Cell Online.

[24]  O. Fiehn,et al.  Metabolite profiling for plant functional genomics , 2000, Nature Biotechnology.

[25]  M. Schmid,et al.  Genome-Wide Insertional Mutagenesis of Arabidopsis thaliana , 2003, Science.

[26]  F. Gaymard,et al.  Tissue-specific expression of Arabidopsis AKT1 gene is consistent with a role in K+ nutrition. , 1996, The Plant journal : for cell and molecular biology.

[27]  C. Shelton,et al.  Annotating Genes of Known and Unknown Function by Large-Scale Coexpression Analysis1[W][OA] , 2008, Plant Physiology.

[28]  D. Baulcombe,et al.  The Rx Gene from Potato Controls Separate Virus Resistance and Cell Death Responses , 1999, Plant Cell.

[29]  C. Koncz,et al.  The promoter of TL-DNA gene 5 controls the tissue-specific expression of chimaeric genes carried by a novel type of Agrobacterium binary vector , 1986, Molecular and General Genetics MGG.

[30]  Susanne von Caemmerer,et al.  Transgenic Introduction of a Glycolate Oxidative Cycle into A. thaliana Chloroplasts Leads to Growth Improvement , 2012, Front. Plant Sci..

[31]  C. Benning.  Evidence supporting a model of voltage-dependent uptake of auxin into Cucurbita vesicles , 1986, Planta.

[32]  O. Fiehn,et al.  High quality metabolomic data for Chlamydomonas reinhardtii , 2008, Plant Methods.

[33]  J. Berry,et al.  Fixation of 18O2 during Photorespiration: Kinetic and Steady-State Studies of the Photorespiratory Carbon Oxidation Cycle with Intact Leaves and Isolated Chloroplasts of C3 Plants 1 , 1978 .

[34]  Kazuki Saito,et al.  Identification of a Flavonol 7-O-Rhamnosyltransferase Gene Determining Flavonoid Pattern in Arabidopsis by Transcriptome Coexpression Analysis and Reverse Genetics*♦ , 2007, Journal of Biological Chemistry.

[35]  Homin K. Lee,et al.  Coexpression analysis of human genes across many microarray data sets. , 2004, Genome research.

[36]  U. Heber,et al.  Metabolic regulation by pH gradients. Inhibition of photosynthesis by indirect proton transfer across the chloroplast envelope. , 1980, Biochimica et biophysica acta.

[37]  C. Somerville,et al.  Inhibition of photosynthesis in Arabidopsis mutants lacking leaf glutamate synthase activity , 1980, Nature.

[38]  K. Shinozaki,et al.  Identification of photorespiratory glutamate:glyoxylate aminotransferase (GGAT) gene in Arabidopsis. , 2003, The Plant journal : for cell and molecular biology.

[39]  P. Jarvis,et al.  A simple method for isolating import‐competent Arabidopsis chloroplasts , 2002, FEBS letters.

[40]  D. Botstein,et al.  Cluster analysis and display of genome-wide expression patterns. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[41]  K. Howitz,et al.  Solubilization, partial purification, and reconstitution of the glycolate/glycerate transporter from chloroplast inner envelope membranes. , 1991, Plant physiology.

[42]  R. Rosenkranz,et al.  Chloroplastic photorespiratory bypass increases photosynthesis and biomass production in Arabidopsis thaliana , 2007, Nature Biotechnology.

[43]  Jun Zhuang,et al.  Global transcript profiling of primary stems from Arabidopsis thaliana identifies candidate genes for missing links in lignin biosynthesis and transcriptional regulators of fiber differentiation. , 2005, The Plant journal : for cell and molecular biology.

[44]  R. E. Mccarty,et al.  Assay of Proton-Coupled Glycolate and D-Glycerate Transport into Chloroplast Inner Envelope Membrane Vesicles by Stopped-Flow Fluorescence , 1993, Plant physiology.

[45]  Takayuki Tohge,et al.  AtABCG29 Is a Monolignol Transporter Involved in Lignin Biosynthesis , 2012, Current Biology.

[46]  Staffan Persson,et al.  Identification of genes required for cellulose synthesis by regression analysis of public microarray data sets. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[47]  O. Fiehn,et al.  Erratum: Metabolite profiling for plant functional genomics (Nat. Biotechnol. (2000) 18: 1157-1161) , 2001 .

[48]  C. R. McClung,et al.  The Photorespiratory Arabidopsis shm1 Mutant Is Deficient in SHM11[W][OA] , 2005, Plant Physiology.