Unbound MEDLINE

The thylakoid membrane proteome of two marine diatoms outlines both diatom-specific and species-specific features of the photosynthetic machinery.

Abstract

The thylakoid membrane of photoautotrophic organisms contains the main components of the photosynthetic electron transport chain. Detailed proteome maps of the thylakoid protein complexes of two marine diatoms, Thalassiosira pseudonana and Phaeodactylum tricornutum, were created by means of two-dimensional blue native (BN)/SDS-PAGE coupled with mass spectrometry analysis. One novel diatom-specific photosystem I (PS I)-associated protein was identified. A second plastid-targeted protein with possible PS I interaction was discovered to be restricted to the centric diatom species T. pseudonana. PGR5/PGRL homologues were found to be the only protein components of PS I-mediated cyclic electron transport common to both species. For the first time, evidence for a possible PS I localization of LI818-like light harvesting proteins (Lhcx) is presented. This study also advances the current knowledge on the light harvesting antenna composition and Lhcx expression in T. pseudonana on the protein level and presents details on the molecular distribution of Lhcx in diatoms. Above mentioned proteins and several others with unknown function provide a broad basis for further mutagenesis analysis, aiming toward further understanding of the composition and function of the photosynthetic apparatus of diatoms. The proteomics approach of this study further served as a tool to confirm and improve genome-derived protein models.

Links

  • Publisher Full Text

    • Authors

    Grouneva I, Rokka A, Aro EM

    Institution

    Department of Biochemistry and Food Chemistry, Molecular Plant Biology, Tykistökatu 6A, FI-20520, University of Turku, Finland.

    Source

    Journal of proteome research 10:12 2011 Dec 2 pg 5338-53

    MeSH

    Amino Acid Sequence
    Chloroplast Proton-Translocating ATPases
    Cytochrome b6f Complex
    Databases, Protein
    Diatoms
    Electron Transport
    Electrophoresis, Polyacrylamide Gel
    Light-Harvesting Protein Complexes
    Molecular Sequence Data
    Photosynthesis
    Photosystem I Protein Complex
    Plastids
    Proteome
    Sequence Alignment
    Solubility
    Species Specificity
    Thylakoids
    Xanthophylls

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    22017178