title: Solute transporters of the plastid envelope membrane.
abstract: Plastids are metabolically extraordinarily active and versatile organelles that are found in all plant cells with the exception of angiosperm pollen grains. Many of the plastid-localized biochemical pathways depend on precursors from the cytosol and, in turn, many cytosolic pathways depend on the supply of precursor molecules from the plastid stroma. Hence, a massive traffic of metabolites occurs across the permeability barrier between plastids and cytosol that is called the plastid envelope membrane. Many of the known plastid envelope solute transporters have been identified by biochemical purification and peptide sequencing. This approach is of limited use for less abundant proteins and for proteins of plastid subtypes that are difficult to isolate in preparative amounts. Hence, the majority of plastid envelope membrane transporters are not yet identified at the molecular level. The availability of fully sequenced plant genomes, the progress in bioinformatics to predict membrane transporters localized in plastids, and the development of highly sensitive proteomics techniques open new avenues toward identifying additional, to date unknown, plastid envelope membrane transporters.
authors.affiliation: Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824-1312, USA. aweber@msu.edu
authors.forename: Andreas P M
authors.initials: AP
authors.lastname: Weber
authors.forename: Rainer
authors.initials: R
authors.lastname: Schwacke
authors.forename: Ulf-Ingo
authors.initials: UI
authors.lastname: Flügge
mesh_terms: D000595:Amino Acid Sequence; D019295:Computational Biology; D017343:Genes, Plant; D007425:Intracellular Membranes / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D018087:Plastids / Q000378:metabolism* / Q000648:ultrastructure; D017386:Sequence Homology, Amino Acid
chemical_list: D026901:Membrane Transport Proteins