title: Involvement of the DnaK-DnaJ-GrpE chaperone team in protein secretion in Escherichia coli.
abstract: We used depletion studies designed to further investigate the role of the DnaK, DnaJ, and GrpE heat shock proteins in the SecB-dependent and SecB-independent secretion pathways. Our previous finding that SecB-deficient strains containing the grpE280 mutation were still secretion proficient raised the possibility that GrpE was not involved in this secretory pathway. Using depletion studies, we now demonstrate a requirement for GrpE in this pathway. In addition, depletion studies demonstrate that while DnaK, DnaJ, and GrpE are involved in the secretion of the SecB-independent proteins (alkaline phosphatase, ribose-binding protein, and beta-lactamase), they are not the primary chaperones in this process.
authors.affiliation: Department of Bacteriology, University of Wisconsin-Madison, 53706, USA.
authors.forename: J
authors.initials: J
authors.lastname: Wild
authors.forename: P
authors.initials: P
authors.lastname: Rossmeissl
authors.forename: W A
authors.initials: WA
authors.lastname: Walter
authors.forename: C A
authors.initials: CA
authors.lastname: Gross
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism* / Q000502:physiology*; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000502:physiology*; D046911:Macromolecular Substances; D018832:Molecular Chaperones / Q000502:physiology*; D033902:Periplasmic Binding Proteins; D021382:Protein Sorting Signals / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; C068113:GrpE protein, Bacteria; C489400:GrpE protein, E coli; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D046911:Macromolecular Substances; D018832:Molecular Chaperones; D033902:Periplasmic Binding Proteins; D021382:Protein Sorting Signals; C028003:RbsB protein, E coli; C057842:SecB protein, Bacteria; D000469:Alkaline Phosphatase; C063842:dnaK protein, E coli