Abstract
The RER retains a specific subset of ER proteins, many of which have been shown to participate in the translocation of nascent secretory and membrane proteins. The mechanism of retention of RER specific membrane proteins is unknown. To study this phenomenon in yeast, where no RER- specific membrane proteins have yet been identified, we expressed the human RER-specific protein, ribophorin I. In all mammalian cell types examined, ribophorin I has been shown to be restricted to the membrane of the RER. Here we ascertain that yeast cells correctly target, assemble, and retain ribophorin I in their RER. Floatation experiments demonstrated that human ribophorin I, expressed in yeast, was membrane associated. Carbonate (pH = 11) washing and Triton X-114 cloud-point precipitations of yeast microsomes indicated that ribophorin I was integrated into the membrane bilayer. Both chromatography on Con A and digestion with endoglycosidase H were used to prove that ribophorin I was glycosylated once, consistent with its expression in mammalian cells. Proteolysis of microsomal membranes and subsequent immunoblotting showed ribophorin I to have assumed the correct transmembrane topology. Sucrose gradient centrifugation studies found ribophorin I to be included only in fractions containing rough membranes and excluded from smooth ones that, on the basis of the distribution of BiP, included smooth ER. Ribosome removal from rough membranes and subsequent isopycnic centrifugation resulted in a shift in the buoyant density of the ribophorin I-containing membranes. Furthermore, the rough and density-shifted fractions were the exclusive location of protein translocation activity. Based on these studies we conclude that sequestration of membrane proteins to rough domains of ER probably occurs in a like manner in yeast and mammalian cells.
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- Amar-Costesec A., Todd J. A., Kreibich G. Segregation of the polypeptide translocation apparatus to regions of the endoplasmic reticulum containing ribophorins and ribosomes. I. Functional tests on rat liver microsomal subfractions. J Cell Biol. 1984 Dec;99(6):2247–2253. doi: 10.1083/jcb.99.6.2247. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ansorge W. Fast and sensitive detection of protein and DNA bands by treatment with potassium permanganate. J Biochem Biophys Methods. 1985 May;11(1):13–20. doi: 10.1016/0165-022x(85)90037-5. [DOI] [PubMed] [Google Scholar]
- Baker D., Hicke L., Rexach M., Schleyer M., Schekman R. Reconstitution of SEC gene product-dependent intercompartmental protein transport. Cell. 1988 Jul 29;54(3):335–344. doi: 10.1016/0092-8674(88)90196-1. [DOI] [PubMed] [Google Scholar]
- Basson M. E., Thorsness M., Rine J. Saccharomyces cerevisiae contains two functional genes encoding 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Proc Natl Acad Sci U S A. 1986 Aug;83(15):5563–5567. doi: 10.1073/pnas.83.15.5563. [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]
- Bordier C. Phase separation of integral membrane proteins in Triton X-114 solution. J Biol Chem. 1981 Feb 25;256(4):1604–1607. [PubMed] [Google Scholar]
- Crimaudo C., Hortsch M., Gausepohl H., Meyer D. I. Human ribophorins I and II: the primary structure and membrane topology of two highly conserved rough endoplasmic reticulum-specific glycoproteins. EMBO J. 1987 Jan;6(1):75–82. doi: 10.1002/j.1460-2075.1987.tb04721.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- 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]
- Evans E. A., Gilmore R., Blobel G. Purification of microsomal signal peptidase as a complex. Proc Natl Acad Sci U S A. 1986 Feb;83(3):581–585. doi: 10.1073/pnas.83.3.581. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hardwick K. G., Lewis M. J., Semenza J., Dean N., Pelham H. R. ERD1, a yeast gene required for the retention of luminal endoplasmic reticulum proteins, affects glycoprotein processing in the Golgi apparatus. EMBO J. 1990 Mar;9(3):623–630. doi: 10.1002/j.1460-2075.1990.tb08154.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harnik-Ort V., Prakash K., Marcantonio E., Colman D. R., Rosenfeld M. G., Adesnik M., Sabatini D. D., Kreibich G. Isolation and characterization of cDNA clones for rat ribophorin I: complete coding sequence and in vitro synthesis and insertion of the encoded product into endoplasmic reticulum membranes. J Cell Biol. 1987 Apr;104(4):855–863. doi: 10.1083/jcb.104.4.855. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hortsch M., Avossa D., Meyer D. I. Characterization of secretory protein translocation: ribosome-membrane interaction in endoplasmic reticulum. J Cell Biol. 1986 Jul;103(1):241–253. doi: 10.1083/jcb.103.1.241. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hortsch M., Griffiths G., Meyer D. I. Restriction of docking protein to the rough endoplasmic reticulum: immunocytochemical localization in rat liver. Eur J Cell Biol. 1985 Sep;38(2):271–279. [PubMed] [Google Scholar]
- Hortsch M., Meyer D. I. Immunochemical analysis of rough and smooth microsomes from rat liver. Segregation of docking protein in rough membranes. Eur J Biochem. 1985 Aug 1;150(3):559–564. doi: 10.1111/j.1432-1033.1985.tb09057.x. [DOI] [PubMed] [Google Scholar]
- Jackson M. R., McCarthy L. R., Harding D., Wilson S., Coughtrie M. W., Burchell B. Cloning of a human liver microsomal UDP-glucuronosyltransferase cDNA. Biochem J. 1987 Mar 1;242(2):581–588. doi: 10.1042/bj2420581. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jackson M. R., Nilsson T., Peterson P. A. Identification of a consensus motif for retention of transmembrane proteins in the endoplasmic reticulum. EMBO J. 1990 Oct;9(10):3153–3162. doi: 10.1002/j.1460-2075.1990.tb07513.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kreibich G., Ulrich B. L., Sabatini D. D. Proteins of rough microsomal membranes related to ribosome binding. I. Identification of ribophorins I and II, membrane proteins characteristics of rough microsomes. J Cell Biol. 1978 May;77(2):464–487. doi: 10.1083/jcb.77.2.464. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lippincott-Schwartz J., Donaldson J. G., Schweizer A., Berger E. G., Hauri H. P., Yuan L. C., Klausner R. D. Microtubule-dependent retrograde transport of proteins into the ER in the presence of brefeldin A suggests an ER recycling pathway. Cell. 1990 Mar 9;60(5):821–836. doi: 10.1016/0092-8674(90)90096-w. [DOI] [PubMed] [Google Scholar]
- Marcantonio E. E., Amar-Costesec A., Kreibich G. Segregation of the polypeptide translocation apparatus to regions of the endoplasmic reticulum containing ribophorins and ribosomes. II. Rat liver microsomal subfractions contain equimolar amounts of ribophorins and ribosomes. J Cell Biol. 1984 Dec;99(6):2254–2259. doi: 10.1083/jcb.99.6.2254. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marriott M., Tanner W. Localization of dolichyl phosphate- and pyrophosphate-dependent glycosyl transfer reactions in Saccharomyces cerevisiae. J Bacteriol. 1979 Aug;139(2):566–572. doi: 10.1128/jb.139.2.566-572.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Munro S., Pelham H. R. A C-terminal signal prevents secretion of luminal ER proteins. Cell. 1987 Mar 13;48(5):899–907. doi: 10.1016/0092-8674(87)90086-9. [DOI] [PubMed] [Google Scholar]
- Nilsson T., Jackson M., Peterson P. A. Short cytoplasmic sequences serve as retention signals for transmembrane proteins in the endoplasmic reticulum. Cell. 1989 Aug 25;58(4):707–718. doi: 10.1016/0092-8674(89)90105-0. [DOI] [PubMed] [Google Scholar]
- Novick P., Ferro S., Schekman R. Order of events in the yeast secretory pathway. Cell. 1981 Aug;25(2):461–469. doi: 10.1016/0092-8674(81)90064-7. [DOI] [PubMed] [Google Scholar]
- Pelham H. R. Evidence that luminal ER proteins are sorted from secreted proteins in a post-ER compartment. EMBO J. 1988 Apr;7(4):913–918. doi: 10.1002/j.1460-2075.1988.tb02896.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pelham H. R. Heat shock and the sorting of luminal ER proteins. EMBO J. 1989 Nov;8(11):3171–3176. doi: 10.1002/j.1460-2075.1989.tb08475.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Päbo S., Bhat B. M., Wold W. S., Peterson P. A. A short sequence in the COOH-terminus makes an adenovirus membrane glycoprotein a resident of the endoplasmic reticulum. Cell. 1987 Jul 17;50(2):311–317. doi: 10.1016/0092-8674(87)90226-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rosenfeld M. G., Marcantonio E. E., Hakimi J., Ort V. M., Atkinson P. H., Sabatini D., Kreibich G. Biosynthesis and processing of ribophorins in the endoplasmic reticulum. J Cell Biol. 1984 Sep;99(3):1076–1082. doi: 10.1083/jcb.99.3.1076. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Rothblatt J. A., Meyer D. I. Secretion in yeast: translocation and glycosylation of prepro-alpha-factor in vitro can occur via an ATP-dependent post-translational mechanism. EMBO J. 1986 May;5(5):1031–1036. doi: 10.1002/j.1460-2075.1986.tb04318.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sanz P., Meyer D. I. Secretion in yeast: preprotein binding to a membrane receptor and ATP-dependent translocation are sequential and separable events in vitro. J Cell Biol. 1989 Jun;108(6):2101–2106. doi: 10.1083/jcb.108.6.2101. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Spurr A. R. A low-viscosity epoxy resin embedding medium for electron microscopy. J Ultrastruct Res. 1969 Jan;26(1):31–43. doi: 10.1016/s0022-5320(69)90033-1. [DOI] [PubMed] [Google Scholar]
- 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]
- Vaux D., Tooze J., Fuller S. Identification by anti-idiotype antibodies of an intracellular membrane protein that recognizes a mammalian endoplasmic reticulum retention signal. Nature. 1990 Jun 7;345(6275):495–502. doi: 10.1038/345495a0. [DOI] [PubMed] [Google Scholar]
- Walter P., Lingappa V. R. Mechanism of protein translocation across the endoplasmic reticulum membrane. Annu Rev Cell Biol. 1986;2:499–516. doi: 10.1146/annurev.cb.02.110186.002435. [DOI] [PubMed] [Google Scholar]