Abstract
Periplasmic domains of cytoplasmic membrane proteins require export signals for proper translocation. These signals were studied by using a MalF-alkaline phosphatase fusion in a genetic selection that allowed the isolation of mislocalization mutants. In the original construct, alkaline phosphatase is fused to the second periplasmic domain of the membrane protein, and its activity is thus confined exclusively to the periplasm. Mutants that no longer translocated alkaline phosphatase were selected by complementation of a serB mutation. A total of 11 deletions in the amino terminus were isolated, all of which spanned at least the third transmembrane segment. This domain immediately precedes the periplasmic domain to which alkaline phosphatase was fused. Our results obtained in vivo support the model that amino-terminal membrane-spanning segments are required for translocation of large periplasmic domains. In addition, we found that the inability to export the alkaline phosphatase domain could be suppressed by a mutation, prlA4, in the secretion apparatus.
Full text
PDF






Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Allard J. D., Bertrand K. P. Membrane topology of the pBR322 tetracycline resistance protein. TetA-PhoA gene fusions and implications for the mechanism of TetA membrane insertion. J Biol Chem. 1992 Sep 5;267(25):17809–17819. [PubMed] [Google Scholar]
- Baneyx F., Georgiou G. Construction and characterization of Escherichia coli strains deficient in multiple secreted proteases: protease III degrades high-molecular-weight substrates in vivo. J Bacteriol. 1991 Apr;173(8):2696–2703. doi: 10.1128/jb.173.8.2696-2703.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bibi E., Stearns S. M., Kaback H. R. The N-terminal 22 amino acid residues in the lactose permease of Escherichia coli are not obligatory for membrane insertion or transport activity. Proc Natl Acad Sci U S A. 1992 Apr 15;89(8):3180–3184. doi: 10.1073/pnas.89.8.3180. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blobel G., Dobberstein B. Transfer of proteins across membranes. I. Presence of proteolytically processed and unprocessed nascent immunoglobulin light chains on membrane-bound ribosomes of murine myeloma. J Cell Biol. 1975 Dec;67(3):835–851. doi: 10.1083/jcb.67.3.835. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boyd D., Beckwith J. The role of charged amino acids in the localization of secreted and membrane proteins. Cell. 1990 Sep 21;62(6):1031–1033. doi: 10.1016/0092-8674(90)90378-r. [DOI] [PubMed] [Google Scholar]
- Boyd D., Manoil C., Beckwith J. Determinants of membrane protein topology. Proc Natl Acad Sci U S A. 1987 Dec;84(23):8525–8529. doi: 10.1073/pnas.84.23.8525. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boyd D., Traxler B., Beckwith J. Analysis of the topology of a membrane protein by using a minimum number of alkaline phosphatase fusions. J Bacteriol. 1993 Jan;175(2):553–556. doi: 10.1128/jb.175.2.553-556.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Calamia J., Manoil C. Membrane protein spanning segments as export signals. J Mol Biol. 1992 Apr 5;224(3):539–543. doi: 10.1016/0022-2836(92)90542-r. [DOI] [PubMed] [Google Scholar]
- Calamia J., Manoil C. lac permease of Escherichia coli: topology and sequence elements promoting membrane insertion. Proc Natl Acad Sci U S A. 1990 Jul;87(13):4937–4941. doi: 10.1073/pnas.87.13.4937. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davidson A. L., Nikaido H. Purification and characterization of the membrane-associated components of the maltose transport system from Escherichia coli. J Biol Chem. 1991 May 15;266(14):8946–8951. [PubMed] [Google Scholar]
- Derman A. I., Beckwith J. Escherichia coli alkaline phosphatase fails to acquire disulfide bonds when retained in the cytoplasm. J Bacteriol. 1991 Dec;173(23):7719–7722. doi: 10.1128/jb.173.23.7719-7722.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Derman A. I., Prinz W. A., Belin D., Beckwith J. Mutations that allow disulfide bond formation in the cytoplasm of Escherichia coli. Science. 1993 Dec 10;262(5140):1744–1747. doi: 10.1126/science.8259521. [DOI] [PubMed] [Google Scholar]
- Derman A. I., Puziss J. W., Bassford P. J., Jr, Beckwith J. A signal sequence is not required for protein export in prlA mutants of Escherichia coli. EMBO J. 1993 Mar;12(3):879–888. doi: 10.1002/j.1460-2075.1993.tb05728.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ehrmann M., Beckwith J. Proper insertion of a complex membrane protein in the absence of its amino-terminal export signal. J Biol Chem. 1991 Sep 5;266(25):16530–16533. [PubMed] [Google Scholar]
- Ehrmann M., Boyd D., Beckwith J. Genetic analysis of membrane protein topology by a sandwich gene fusion approach. Proc Natl Acad Sci U S A. 1990 Oct;87(19):7574–7578. doi: 10.1073/pnas.87.19.7574. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Emr S. D., Hanley-Way S., Silhavy T. J. Suppressor mutations that restore export of a protein with a defective signal sequence. Cell. 1981 Jan;23(1):79–88. doi: 10.1016/0092-8674(81)90272-5. [DOI] [PubMed] [Google Scholar]
- Hartmann E., Rapoport T. A., Lodish H. F. Predicting the orientation of eukaryotic membrane-spanning proteins. Proc Natl Acad Sci U S A. 1989 Aug;86(15):5786–5790. doi: 10.1073/pnas.86.15.5786. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ito K., Bassford P. J., Jr, Beckwith J. Protein localization in E. coli: is there a common step in the secretion of periplasmic and outer-membrane proteins? Cell. 1981 Jun;24(3):707–717. doi: 10.1016/0092-8674(81)90097-0. [DOI] [PubMed] [Google Scholar]
- Ito K., Wittekind M., Nomura M., Shiba K., Yura T., Miura A., Nashimoto H. A temperature-sensitive mutant of E. coli exhibiting slow processing of exported proteins. Cell. 1983 Mar;32(3):789–797. doi: 10.1016/0092-8674(83)90065-x. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Lloyd A. D., Kadner R. J. Topology of the Escherichia coli uhpT sugar-phosphate transporter analyzed by using TnphoA fusions. J Bacteriol. 1990 Apr;172(4):1688–1693. doi: 10.1128/jb.172.4.1688-1693.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McGovern K., Beckwith J. Membrane insertion of the Escherichia coli MalF protein in cells with impaired secretion machinery. J Biol Chem. 1991 Nov 5;266(31):20870–20876. [PubMed] [Google Scholar]
- McGovern K., Ehrmann M., Beckwith J. Decoding signals for membrane protein assembly using alkaline phosphatase fusions. EMBO J. 1991 Oct;10(10):2773–2782. doi: 10.1002/j.1460-2075.1991.tb07826.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Michaelis S., Inouye H., Oliver D., Beckwith J. Mutations that alter the signal sequence of alkaline phosphatase in Escherichia coli. J Bacteriol. 1983 Apr;154(1):366–374. doi: 10.1128/jb.154.1.366-374.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nilsson I., von Heijne G. Fine-tuning the topology of a polytopic membrane protein: role of positively and negatively charged amino acids. Cell. 1990 Sep 21;62(6):1135–1141. doi: 10.1016/0092-8674(90)90390-z. [DOI] [PubMed] [Google Scholar]
- Puziss J. W., Strobel S. M., Bassford P. J., Jr Export of maltose-binding protein species with altered charge distribution surrounding the signal peptide hydrophobic core in Escherichia coli cells harboring prl suppressor mutations. J Bacteriol. 1992 Jan;174(1):92–101. doi: 10.1128/jb.174.1.92-101.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sanger F., Coulson A. R., Hong G. F., Hill D. F., Petersen G. B. Nucleotide sequence of bacteriophage lambda DNA. J Mol Biol. 1982 Dec 25;162(4):729–773. doi: 10.1016/0022-2836(82)90546-0. [DOI] [PubMed] [Google Scholar]
- Schatz P. J., Beckwith J. Genetic analysis of protein export in Escherichia coli. Annu Rev Genet. 1990;24:215–248. doi: 10.1146/annurev.ge.24.120190.001243. [DOI] [PubMed] [Google Scholar]
- Shuman H. A., Silhavy T. J., Beckwith J. R. Labeling of proteins with beta-galactosidase by gene fusion. Identification of a cytoplasmic membrane component of the Escherichia coli maltose transport system. J Biol Chem. 1980 Jan 10;255(1):168–174. [PubMed] [Google Scholar]
- Traxler B., Lee C., Boyd D., Beckwith J. The dynamics of assembly of a cytoplasmic membrane protein in Escherichia coli. J Biol Chem. 1992 Mar 15;267(8):5339–5345. [PubMed] [Google Scholar]
- von Heijne G. The signal peptide. J Membr Biol. 1990 May;115(3):195–201. doi: 10.1007/BF01868635. [DOI] [PubMed] [Google Scholar]
- von Heijne G. Transcending the impenetrable: how proteins come to terms with membranes. Biochim Biophys Acta. 1988 Jun 9;947(2):307–333. doi: 10.1016/0304-4157(88)90013-5. [DOI] [PubMed] [Google Scholar]