Biochemical characterization of symbiosome membrane proteins from Medicago truncatula root nodules

Authors

  • Christina M. Catalano,

    1. Department of Plant and Soil Sciences and the Delaware Biotechnology Institute, University of Delaware, Newark, DE, USA
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  • William S. Lane,

    1. Harvard Microchemistry and Proteomics Analysis Facility, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
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  • D. Janine Sherrier

    Corresponding author
    1. Department of Plant and Soil Sciences and the Delaware Biotechnology Institute, University of Delaware, Newark, DE, USA
    • Department of Plant and Soil Sciences and Delaware Biotechnology Institute, Newark, DE, 19711, USA Fax: +302-831-3447
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Abstract

The symbiosome membrane represents a specialized plant membrane that forms both a structural and a functional interface between the legume plant and its bacterial counterpart. In this study, the symbiosome membrane protein profile from the model system Medicago truncatula and the corresponding bacterium Sinorhizobium meliloti was examined using two-dimensional electrophoresis and microcapillary high-performance liquid chromatography (HPLC) tandem mass spectrometry. The identities of 51 proteins were obtained and these proteins were categorized into functional classes to indicate biochemical roles. Symbiosome membrane proteins include an H+-ATPase, ENOD16, ENOD8, nodulin-25, BiP, HSP70, PDI, multifunctional aquaporin, a putative syntaxin, and other proteins of known and unknown identity and function. The majority of the proteins identified were involved with protein destination and storage. These results allow us to understand better the biochemical composition of the symbiosome membrane and thus provide a basis to hypothesize mechanisms of symbiosome membrane formation and function.

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