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. 1993 Jan 1;120(1):95–102. doi: 10.1083/jcb.120.1.95

Reconstitution of protein translocation from solubilized yeast membranes reveals topologically distinct roles for BiP and cytosolic Hsc70

PMCID: PMC2119491  PMID: 8416998

Abstract

We reconstituted prepro-alpha-factor translocation and signal peptide processing using a yeast microsomal detergent soluble fraction formed into vesicles with soybean phospholipids. Reconstituted translocation required ATP, and was deficient when sec63 and kar2 (BiP) mutant cells were used as a source of membranes. Normal translocation was observed with vesicles reconstituted from a mixture of pure wild-type yeast BiP and a soluble fraction of kar2 mutant membranes. Two other heat-shock cognate (hsc) 70 homologs, yeast cytosolic hsc70 (Ssalp) and E. coli dnaK protein did not replace BiP. Conversely, BiP was not active under conditions where translocation into native ER vesicles required cytosolic hsc70. We conclude that cytosolic hsc70 and BiP serve noninterchangeable roles in polypeptide translocation, possibly because distinct, asymmetrically oriented membrane proteins are required to recruit each protein to opposing surfaces of the ER membrane.

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Selected References

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  1. Brundage L., Hendrick J. P., Schiebel E., Driessen A. J., Wickner W. The purified E. coli integral membrane protein SecY/E is sufficient for reconstitution of SecA-dependent precursor protein translocation. Cell. 1990 Aug 24;62(4):649–657. doi: 10.1016/0092-8674(90)90111-q. [DOI] [PubMed] [Google Scholar]
  2. Bulleid N. J., Freedman R. B. Defective co-translational formation of disulphide bonds in protein disulphide-isomerase-deficient microsomes. Nature. 1988 Oct 13;335(6191):649–651. doi: 10.1038/335649a0. [DOI] [PubMed] [Google Scholar]
  3. Böhni P. C., Deshaies R. J., Schekman R. W. SEC11 is required for signal peptide processing and yeast cell growth. J Cell Biol. 1988 Apr;106(4):1035–1042. doi: 10.1083/jcb.106.4.1035. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Caplan A. J., Douglas M. G. Characterization of YDJ1: a yeast homologue of the bacterial dnaJ protein. J Cell Biol. 1991 Aug;114(4):609–621. doi: 10.1083/jcb.114.4.609. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chirico W. J., Waters M. G., Blobel G. 70K heat shock related proteins stimulate protein translocation into microsomes. Nature. 1988 Apr 28;332(6167):805–810. doi: 10.1038/332805a0. [DOI] [PubMed] [Google Scholar]
  6. Crooke E., Guthrie B., Lecker S., Lill R., Wickner W. ProOmpA is stabilized for membrane translocation by either purified E. coli trigger factor or canine signal recognition particle. Cell. 1988 Sep 23;54(7):1003–1011. doi: 10.1016/0092-8674(88)90115-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Deshaies R. J., Koch B. D., Werner-Washburne M., Craig E. A., Schekman R. A subfamily of stress proteins facilitates translocation of secretory and mitochondrial precursor polypeptides. Nature. 1988 Apr 28;332(6167):800–805. doi: 10.1038/332800a0. [DOI] [PubMed] [Google Scholar]
  8. Deshaies R. J., Sanders S. L., Feldheim D. A., Schekman R. Assembly of yeast Sec proteins involved in translocation into the endoplasmic reticulum into a membrane-bound multisubunit complex. Nature. 1991 Feb 28;349(6312):806–808. doi: 10.1038/349806a0. [DOI] [PubMed] [Google Scholar]
  9. Deshaies R. J., Schekman R. A yeast mutant defective at an early stage in import of secretory protein precursors into the endoplasmic reticulum. J Cell Biol. 1987 Aug;105(2):633–645. doi: 10.1083/jcb.105.2.633. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Deshaies R. J., Schekman R. SEC62 encodes a putative membrane protein required for protein translocation into the yeast endoplasmic reticulum. J Cell Biol. 1989 Dec;109(6 Pt 1):2653–2664. doi: 10.1083/jcb.109.6.2653. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Deshaies R. J., Schekman R. Structural and functional dissection of Sec62p, a membrane-bound component of the yeast endoplasmic reticulum protein import machinery. Mol Cell Biol. 1990 Nov;10(11):6024–6035. doi: 10.1128/mcb.10.11.6024. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Driessen A. J., Wickner W. Solubilization and functional reconstitution of the protein-translocation enzymes of Escherichia coli. Proc Natl Acad Sci U S A. 1990 Apr;87(8):3107–3111. doi: 10.1073/pnas.87.8.3107. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Ellis J. Proteins as molecular chaperones. 1987 Jul 30-Aug 5Nature. 328(6129):378–379. doi: 10.1038/328378a0. [DOI] [PubMed] [Google Scholar]
  14. Feldheim D., Rothblatt J., Schekman R. Topology and functional domains of Sec63p, an endoplasmic reticulum membrane protein required for secretory protein translocation. Mol Cell Biol. 1992 Jul;12(7):3288–3296. doi: 10.1128/mcb.12.7.3288. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Flynn G. C., Chappell T. G., Rothman J. E. Peptide binding and release by proteins implicated as catalysts of protein assembly. Science. 1989 Jul 28;245(4916):385–390. doi: 10.1126/science.2756425. [DOI] [PubMed] [Google Scholar]
  16. Flynn G. C., Pohl J., Flocco M. T., Rothman J. E. Peptide-binding specificity of the molecular chaperone BiP. Nature. 1991 Oct 24;353(6346):726–730. doi: 10.1038/353726a0. [DOI] [PubMed] [Google Scholar]
  17. Gething M. J., Sambrook J. Protein folding in the cell. Nature. 1992 Jan 2;355(6355):33–45. doi: 10.1038/355033a0. [DOI] [PubMed] [Google Scholar]
  18. Green N., Fang H., Walter P. Mutants in three novel complementation groups inhibit membrane protein insertion into and soluble protein translocation across the endoplasmic reticulum membrane of Saccharomyces cerevisiae. J Cell Biol. 1992 Feb;116(3):597–604. doi: 10.1083/jcb.116.3.597. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Görlich D., Hartmann E., Prehn S., Rapoport T. A. A protein of the endoplasmic reticulum involved early in polypeptide translocation. Nature. 1992 May 7;357(6373):47–52. doi: 10.1038/357047a0. [DOI] [PubMed] [Google Scholar]
  20. Hansen W., Garcia P. D., Walter P. In vitro protein translocation across the yeast endoplasmic reticulum: ATP-dependent posttranslational translocation of the prepro-alpha-factor. Cell. 1986 May 9;45(3):397–406. doi: 10.1016/0092-8674(86)90325-9. [DOI] [PubMed] [Google Scholar]
  21. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  22. Luke M. M., Sutton A., Arndt K. T. Characterization of SIS1, a Saccharomyces cerevisiae homologue of bacterial dnaJ proteins. J Cell Biol. 1991 Aug;114(4):623–638. doi: 10.1083/jcb.114.4.623. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Müsch A., Wiedmann M., Rapoport T. A. Yeast Sec proteins interact with polypeptides traversing the endoplasmic reticulum membrane. Cell. 1992 Apr 17;69(2):343–352. doi: 10.1016/0092-8674(92)90414-8. [DOI] [PubMed] [Google Scholar]
  24. Nicchitta C. V., Blobel G. Assembly of translocation-competent proteoliposomes from detergent-solubilized rough microsomes. Cell. 1990 Jan 26;60(2):259–269. doi: 10.1016/0092-8674(90)90741-v. [DOI] [PubMed] [Google Scholar]
  25. Nicchitta C. V., Migliaccio G., Blobel G. Biochemical fractionation and assembly of the membrane components that mediate nascent chain targeting and translocation. Cell. 1991 May 17;65(4):587–598. doi: 10.1016/0092-8674(91)90091-c. [DOI] [PubMed] [Google Scholar]
  26. Normington K., Kohno K., Kozutsumi Y., Gething M. J., Sambrook J. S. cerevisiae encodes an essential protein homologous in sequence and function to mammalian BiP. Cell. 1989 Jun 30;57(7):1223–1236. doi: 10.1016/0092-8674(89)90059-7. [DOI] [PubMed] [Google Scholar]
  27. Pelham H. R. Speculations on the functions of the major heat shock and glucose-regulated proteins. Cell. 1986 Sep 26;46(7):959–961. doi: 10.1016/0092-8674(86)90693-8. [DOI] [PubMed] [Google Scholar]
  28. Rose M. D., Misra L. M., Vogel J. P. KAR2, a karyogamy gene, is the yeast homolog of the mammalian BiP/GRP78 gene. Cell. 1989 Jun 30;57(7):1211–1221. doi: 10.1016/0092-8674(89)90058-5. [DOI] [PubMed] [Google Scholar]
  29. Rothblatt J. A., Deshaies R. J., Sanders S. L., Daum G., Schekman R. Multiple genes are required for proper insertion of secretory proteins into the endoplasmic reticulum in yeast. J Cell Biol. 1989 Dec;109(6 Pt 1):2641–2652. doi: 10.1083/jcb.109.6.2641. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Rothblatt J. A., Meyer D. I. Secretion in yeast: reconstitution of the translocation and glycosylation of alpha-factor and invertase in a homologous cell-free system. Cell. 1986 Feb 28;44(4):619–628. doi: 10.1016/0092-8674(86)90271-0. [DOI] [PubMed] [Google Scholar]
  31. Rothman J. E. Polypeptide chain binding proteins: catalysts of protein folding and related processes in cells. Cell. 1989 Nov 17;59(4):591–601. doi: 10.1016/0092-8674(89)90005-6. [DOI] [PubMed] [Google Scholar]
  32. Sadler I., Chiang A., Kurihara T., Rothblatt J., Way J., Silver P. A yeast gene important for protein assembly into the endoplasmic reticulum and the nucleus has homology to DnaJ, an Escherichia coli heat shock protein. J Cell Biol. 1989 Dec;109(6 Pt 1):2665–2675. doi: 10.1083/jcb.109.6.2665. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Sanders S. L., Whitfield K. M., Vogel J. P., Rose M. D., Schekman R. W. Sec61p and BiP directly facilitate polypeptide translocation into the ER. Cell. 1992 Apr 17;69(2):353–365. doi: 10.1016/0092-8674(92)90415-9. [DOI] [PubMed] [Google Scholar]
  34. Simon S. M., Blobel G. A protein-conducting channel in the endoplasmic reticulum. Cell. 1991 May 3;65(3):371–380. doi: 10.1016/0092-8674(91)90455-8. [DOI] [PubMed] [Google Scholar]
  35. Stirling C. J., Hewitt E. W. The S. cerevisiae SEC65 gene encodes a component of yeast signal recognition particle with homology to human SRP19. Nature. 1992 Apr 9;356(6369):534–537. doi: 10.1038/356534a0. [DOI] [PubMed] [Google Scholar]
  36. Stirling C. J., Rothblatt J., Hosobuchi M., Deshaies R., Schekman R. Protein translocation mutants defective in the insertion of integral membrane proteins into the endoplasmic reticulum. Mol Biol Cell. 1992 Feb;3(2):129–142. doi: 10.1091/mbc.3.2.129. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Toyn J., Hibbs A. R., Sanz P., Crowe J., Meyer D. I. In vivo and in vitro analysis of ptl1, a yeast ts mutant with a membrane-associated defect in protein translocation. EMBO J. 1988 Dec 20;7(13):4347–4353. doi: 10.1002/j.1460-2075.1988.tb03333.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Vogel J. P., Misra L. M., Rose M. D. Loss of BiP/GRP78 function blocks translocation of secretory proteins in yeast. J Cell Biol. 1990 Jun;110(6):1885–1895. doi: 10.1083/jcb.110.6.1885. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Waters M. G., Blobel G. Secretory protein translocation in a yeast cell-free system can occur posttranslationally and requires ATP hydrolysis. J Cell Biol. 1986 May;102(5):1543–1550. doi: 10.1083/jcb.102.5.1543. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Waters M. G., Chirico W. J., Blobel G. Protein translocation across the yeast microsomal membrane is stimulated by a soluble factor. J Cell Biol. 1986 Dec;103(6 Pt 2):2629–2636. doi: 10.1083/jcb.103.6.2629. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Waters M. G., Evans E. A., Blobel G. Prepro-alpha-factor has a cleavable signal sequence. J Biol Chem. 1988 May 5;263(13):6209–6214. [PubMed] [Google Scholar]
  42. Werner-Washburne M., Stone D. E., Craig E. A. Complex interactions among members of an essential subfamily of hsp70 genes in Saccharomyces cerevisiae. Mol Cell Biol. 1987 Jul;7(7):2568–2577. doi: 10.1128/mcb.7.7.2568. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Yamamoto T., McIntyre J., Sell S. M., Georgopoulos C., Skowyra D., Zylicz M. Enzymology of the pre-priming steps in lambda dv DNA replication in vitro. J Biol Chem. 1987 Jun 15;262(17):7996–7999. [PubMed] [Google Scholar]
  44. Zylicz M., Ang D., Liberek K., Georgopoulos C. Initiation of lambda DNA replication with purified host- and bacteriophage-encoded proteins: the role of the dnaK, dnaJ and grpE heat shock proteins. EMBO J. 1989 May;8(5):1601–1608. doi: 10.1002/j.1460-2075.1989.tb03544.x. [DOI] [PMC free article] [PubMed] [Google Scholar]

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