Biochemical Studies of Bacterial Protein Export
Studies on the mechanisms of protein secretion and transport have been, until recently, confined to animal cells. In the past few years genetic and biochemical studies with bacteria have contributed greatly to our knowledge of mechanisms of protein secretion and localization (reviews by Davis and Tai 1980; Wickner 1980; Osborn and Wu 1980; Michaelis and Beckwith 1982; Randall and Hardy 1984; Benson et al. 1985). In particular, selection of mutants has permitted the definition of the function of the cleavable signal sequence and the identification of many gene products that may be involved in protein export (see Beckwith and Ferro-Novick, this volume; Lunn et al., this volume). In addition, several signal peptidases have been purified and characterized and their genes identified (Date and Wickner 1981; Innis et al. 1984; Yu et al. 1984; Zwizinski and Wickner 1980; Ray et al., this volume). Moreoever, since the outer surface of the bacterial membrane is readily accessible to manipulation, we have been able to use extracellular radioactive labeling or protease digestions of protruding secreted nascent chains to demonstrate directly the contranslational secretion (Smith et al. 1977, 1978) that had been inferred from the earlier in vitro work. The study of accessibility of nascent chains accumulates on the inner surface of the cytoplasmic membrane before the chains reach the outer surface (Randall 1983).
KeywordsSedimentation Adenosine Bacillus Polypeptide Cytosol
Unable to display preview. Download preview PDF.
- Daniels CJ, Bole DG, Quay SC, Oxender DL (1981) A role for membrane potential in the secretion of protein into the periplasm of Escherichia coli. Proc Natl Acad Sci USA 77: 4669–4673Google Scholar
- Kreibich G, Czako-Graham M, Grebenau R, Mok W, Rodriguez-Boulan E, Sabatini D (1978 a) Characterization of the ribosomal binding site in rat liver rough microsomes: ribophorins I and II, two integral membrane proteins related to ribosome binding. J Supramol Struct 8: 279–302PubMedCrossRefGoogle Scholar
- Pages JM, Anba J, Bernadac A, Shinagawa H, Nakata A, Lazdunski C (1984) Normal precursors of periplasmic proteins accumulated in the cytoplasm are not exported posttranslationally in Escherichia coli. J Biochem 143: 499–505Google Scholar
- Salisbury JL, Condeelis JS, Satir P (1983) Receptor-mediated endocytosis: machinery and regulation of the clathrin-coated vesicle pathway. Int Rev Exp Pathol 24: 2–63Google Scholar