25
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Phylogenomic analysis of the Chlamydomonas genome unmasks proteins potentially involved in photosynthetic function and regulation

      review-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Chlamydomonas reinhardtii, a unicellular green alga, has been exploited as a reference organism for identifying proteins and activities associated with the photosynthetic apparatus and the functioning of chloroplasts. Recently, the full genome sequence of Chlamydomonas was generated and a set of gene models, representing all genes on the genome, was developed. Using these gene models, and gene models developed for the genomes of other organisms, a phylogenomic, comparative analysis was performed to identify proteins encoded on the Chlamydomonas genome which were likely involved in chloroplast functions (or specifically associated with the green algal lineage); this set of proteins has been designated the GreenCut. Further analyses of those GreenCut proteins with uncharacterized functions and the generation of mutant strains aberrant for these proteins are beginning to unmask new layers of functionality/regulation that are integrated into the workings of the photosynthetic apparatus.

          Related collections

          Most cited references84

          • Record: found
          • Abstract: found
          • Article: not found

          A pigment-binding protein essential for regulation of photosynthetic light harvesting.

          Photosynthetic light harvesting in plants is regulated in response to changes in incident light intensity. Absorption of light that exceeds a plant's capacity for fixation of CO2 results in thermal dissipation of excitation energy in the pigment antenna of photosystem II by a poorly understood mechanism. This regulatory process, termed nonphotochemical quenching, maintains the balance between dissipation and utilization of light energy to minimize generation of oxidizing molecules, thereby protecting the plant against photo-oxidative damage. To identify specific proteins that are involved in nonphotochemical quenching, we have isolated mutants of Arabidopsis thaliana that cannot dissipate excess absorbed light energy. Here we show that the gene encoding PsbS, an intrinsic chlorophyll-binding protein of photosystem II, is necessary for nonphotochemical quenching but not for efficient light harvesting and photosynthesis. These results indicate that PsbS may be the site for nonphotochemical quenching, a finding that has implications for the functional evolution of pigment-binding proteins.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Genome sequence of the ultrasmall unicellular red alga Cyanidioschyzon merolae 10D.

            Small, compact genomes of ultrasmall unicellular algae provide information on the basic and essential genes that support the lives of photosynthetic eukaryotes, including higher plants. Here we report the 16,520,305-base-pair sequence of the 20 chromosomes of the unicellular red alga Cyanidioschyzon merolae 10D as the first complete algal genome. We identified 5,331 genes in total, of which at least 86.3% were expressed. Unique characteristics of this genomic structure include: a lack of introns in all but 26 genes; only three copies of ribosomal DNA units that maintain the nucleolus; and two dynamin genes that are involved only in the division of mitochondria and plastids. The conserved mosaic origin of Calvin cycle enzymes in this red alga and in green plants supports the hypothesis of the existence of single primary plastid endosymbiosis. The lack of a myosin gene, in addition to the unexpressed actin gene, suggests a simpler system of cytokinesis. These results indicate that the C. merolae genome provides a model system with a simple gene composition for studying the origin, evolution and fundamental mechanisms of eukaryotic cells.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Green evolution and dynamic adaptations revealed by genomes of the marine picoeukaryotes Micromonas.

              Picoeukaryotes are a taxonomically diverse group of organisms less than 2 micrometers in diameter. Photosynthetic marine picoeukaryotes in the genus Micromonas thrive in ecosystems ranging from tropical to polar and could serve as sentinel organisms for biogeochemical fluxes of modern oceans during climate change. These broadly distributed primary producers belong to an anciently diverged sister clade to land plants. Although Micromonas isolates have high 18S ribosomal RNA gene identity, we found that genomes from two isolates shared only 90% of their predicted genes. Their independent evolutionary paths were emphasized by distinct riboswitch arrangements as well as the discovery of intronic repeat elements in one isolate, and in metagenomic data, but not in other genomes. Divergence appears to have been facilitated by selection and acquisition processes that actively shape the repertoire of genes that are mutually exclusive between the two isolates differently than the core genes. Analyses of the Micromonas genomes offer valuable insights into ecological differentiation and the dynamic nature of early plant evolution.
                Bookmark

                Author and article information

                Contributors
                +650-325-1521 , arthurg@stanford.edu
                Journal
                Photosynth Res
                Photosynthesis Research
                Springer Netherlands (Dordrecht )
                0166-8595
                1573-5079
                20 May 2010
                20 May 2010
                November 2010
                : 106
                : 1-2
                : 3-17
                Affiliations
                [1 ]Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305 USA
                [2 ]Department of Chemistry and Biochemistry, University of California—Los Angeles, Los Angeles, CA 90095-1569 USA
                [3 ]Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102 USA
                [4 ]Unité Mixte de Recherche 7141 CNRS, Institut de Biologie Physico-Chimique, Paris, France
                [5 ]UPMC Université Paris 06, Paris, France
                [6 ]Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, University of California—Los Angeles, Los Angeles, CA 90095 USA
                [7 ]Institute for Genomics and Proteomics, University of California—Los Angeles, Los Angeles, CA 90095-1569 USA
                Article
                9555
                10.1007/s11120-010-9555-7
                2947710
                20490922
                1d50807e-f626-4de2-83a4-af5385d1ae42
                © The Author(s) 2010
                History
                : 11 February 2010
                : 16 April 2010
                Categories
                Review
                Custom metadata
                © Springer Science+Business Media B.V. 2010

                Plant science & Botany
                chloroplast,regulation,chlamydomonas,phylogenomics,greencut
                Plant science & Botany
                chloroplast, regulation, chlamydomonas, phylogenomics, greencut

                Comments

                Comment on this article