Abstract
Sphingolipids are normally necessary for growth of Saccharomyces cerevisiae cells, but mutant strains that bypass the need for sphingolipids have been identified. Such bypass mutants fail to grow under stressful conditions, including low pH (pH 4.1), when they lack sphingolipids. To begin to understand why sphingolipids seem to be necessary for coping with low-pH stress, we screened a genomic library and selected a suppressor gene, CWP2 (cell wall protein 2), that when present in multiple copies partially compensates for the lack of sphingolipids and enhances survival at low pH. To explain these results, we present evidence that sphingolipids are required for a normal rate of transport of glycosylphosphatidylinositol (GPI)-anchored proteins, including Cwp2 and Gas1/Gpg1, from the endoplasmic reticulum (ER) to the Golgi apparatus. The effect of sphingolipids is specific for transport of GPI-anchored proteins because no effect on the rate of transport of carboxypeptidase Y, a non-GPI-anchored protein, was observed. Since the Gasl protein accumulated in the ER with a GPI anchor in cells lacking sphingolipids, we conclude that sphingolipids are not necessary for anchor attachment. Therefore, sphingolipids must be necessary for a step in formation of COPII vesicles or for their transport to the Golgi apparatus. Our data identify the Cwp2 protein as a vital component in protecting cells from the stress of low pH.
Full Text
The Full Text of this article is available as a PDF (436.9 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Ballou L. R. Sphingolipids and cell function. Immunol Today. 1992 Sep;13(9):339–341. doi: 10.1016/0167-5699(92)90167-6. [DOI] [PubMed] [Google Scholar]
- Barettino D., Feigenbutz M., Valcárcel R., Stunnenberg H. G. Improved method for PCR-mediated site-directed mutagenesis. Nucleic Acids Res. 1994 Feb 11;22(3):541–542. doi: 10.1093/nar/22.3.541. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Barlowe C., Orci L., Yeung T., Hosobuchi M., Hamamoto S., Salama N., Rexach M. F., Ravazzola M., Amherdt M., Schekman R. COPII: a membrane coat formed by Sec proteins that drive vesicle budding from the endoplasmic reticulum. Cell. 1994 Jun 17;77(6):895–907. doi: 10.1016/0092-8674(94)90138-4. [DOI] [PubMed] [Google Scholar]
- Bednarek S. Y., Ravazzola M., Hosobuchi M., Amherdt M., Perrelet A., Schekman R., Orci L. COPI- and COPII-coated vesicles bud directly from the endoplasmic reticulum in yeast. Cell. 1995 Dec 29;83(7):1183–1196. doi: 10.1016/0092-8674(95)90144-2. [DOI] [PubMed] [Google Scholar]
- Belka C., Wiegmann K., Adam D., Holland R., Neuloh M., Herrmann F., Krönke M., Brach M. A. Tumor necrosis factor (TNF)-alpha activates c-raf-1 kinase via the p55 TNF receptor engaging neutral sphingomyelinase. EMBO J. 1995 Mar 15;14(6):1156–1165. doi: 10.1002/j.1460-2075.1995.tb07099.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bonner W. M., Laskey R. A. A film detection method for tritium-labelled proteins and nucleic acids in polyacrylamide gels. Eur J Biochem. 1974 Jul 1;46(1):83–88. doi: 10.1111/j.1432-1033.1974.tb03599.x. [DOI] [PubMed] [Google Scholar]
- Bose R., Verheij M., Haimovitz-Friedman A., Scotto K., Fuks Z., Kolesnick R. Ceramide synthase mediates daunorubicin-induced apoptosis: an alternative mechanism for generating death signals. Cell. 1995 Aug 11;82(3):405–414. doi: 10.1016/0092-8674(95)90429-8. [DOI] [PubMed] [Google Scholar]
- Brown D. A. Interactions between GPI-anchored proteins and membrane lipids. Trends Cell Biol. 1992 Nov;2(11):338–343. [PubMed] [Google Scholar]
- Buede R., Rinker-Schaffer C., Pinto W. J., Lester R. L., Dickson R. C. Cloning and characterization of LCB1, a Saccharomyces gene required for biosynthesis of the long-chain base component of sphingolipids. J Bacteriol. 1991 Jul;173(14):4325–4332. doi: 10.1128/jb.173.14.4325-4332.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carver M. A., Turco S. J. Cell-free biosynthesis of lipophosphoglycan from Leishmania donovani. Characterization of microsomal galactosyltransferase and mannosyltransferase activities. J Biol Chem. 1991 Jun 15;266(17):10974–10981. [PubMed] [Google Scholar]
- Conzelmann A., Puoti A., Lester R. L., Desponds C. Two different types of lipid moieties are present in glycophosphoinositol-anchored membrane proteins of Saccharomyces cerevisiae. EMBO J. 1992 Feb;11(2):457–466. doi: 10.1002/j.1460-2075.1992.tb05075.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conzelmann A., Riezman H., Desponds C., Bron C. A major 125-kd membrane glycoprotein of Saccharomyces cerevisiae is attached to the lipid bilayer through an inositol-containing phospholipid. EMBO J. 1988 Jul;7(7):2233–2240. doi: 10.1002/j.1460-2075.1988.tb03063.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Coroneos E., Martinez M., McKenna S., Kester M. Differential regulation of sphingomyelinase and ceramidase activities by growth factors and cytokines. Implications for cellular proliferation and differentiation. J Biol Chem. 1995 Oct 6;270(40):23305–23309. doi: 10.1074/jbc.270.40.23305. [DOI] [PubMed] [Google Scholar]
- Dickson R. C., Wells G. B., Schmidt A., Lester R. L. Isolation of mutant Saccharomyces cerevisiae strains that survive without sphingolipids. Mol Cell Biol. 1990 May;10(5):2176–2181. doi: 10.1128/mcb.10.5.2176. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Doering T. L., Schekman R. GPI anchor attachment is required for Gas1p transport from the endoplasmic reticulum in COP II vesicles. EMBO J. 1996 Jan 2;15(1):182–191. [PMC free article] [PubMed] [Google Scholar]
- Englund P. T. The structure and biosynthesis of glycosyl phosphatidylinositol protein anchors. Annu Rev Biochem. 1993;62:121–138. doi: 10.1146/annurev.bi.62.070193.001005. [DOI] [PubMed] [Google Scholar]
- Esteve P., del Peso L., Lacal J. C. Induction of apoptosis by rho in NIH 3T3 cells requires two complementary signals. Ceramides function as a progression factor for apoptosis. Oncogene. 1995 Dec 21;11(12):2657–2665. [PubMed] [Google Scholar]
- Fankhauser C., Homans S. W., Thomas-Oates J. E., McConville M. J., Desponds C., Conzelmann A., Ferguson M. A. Structures of glycosylphosphatidylinositol membrane anchors from Saccharomyces cerevisiae. J Biol Chem. 1993 Dec 15;268(35):26365–26374. [PubMed] [Google Scholar]
- Ferrari G., Anderson B. L., Stephens R. M., Kaplan D. R., Greene L. A. Prevention of apoptotic neuronal death by GM1 ganglioside. Involvement of Trk neurotrophin receptors. J Biol Chem. 1995 Feb 17;270(7):3074–3080. doi: 10.1074/jbc.270.7.3074. [DOI] [PubMed] [Google Scholar]
- Hakomori S. Bifunctional role of glycosphingolipids. Modulators for transmembrane signaling and mediators for cellular interactions. J Biol Chem. 1990 Nov 5;265(31):18713–18716. [PubMed] [Google Scholar]
- Hannun Y. A., Obeid L. M. Ceramide: an intracellular signal for apoptosis. Trends Biochem Sci. 1995 Feb;20(2):73–77. doi: 10.1016/s0968-0004(00)88961-6. [DOI] [PubMed] [Google Scholar]
- Hannun Y. A. The sphingomyelin cycle and the second messenger function of ceramide. J Biol Chem. 1994 Feb 4;269(5):3125–3128. [PubMed] [Google Scholar]
- Horvath A., Sütterlin C., Manning-Krieg U., Movva N. R., Riezman H. Ceramide synthesis enhances transport of GPI-anchored proteins to the Golgi apparatus in yeast. EMBO J. 1994 Aug 15;13(16):3687–3695. doi: 10.1002/j.1460-2075.1994.tb06678.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hudson P. L., Pedersen W. A., Saltsman W. S., Liscovitch M., MacLaughlin D. T., Donahoe P. K., Blusztajn J. K. Modulation by sphingolipids of calcium signals evoked by epidermal growth factor. J Biol Chem. 1994 Aug 26;269(34):21885–21890. [PubMed] [Google Scholar]
- Johnston S. A., Hopper J. E. Isolation of the yeast regulatory gene GAL4 and analysis of its dosage effects on the galactose/melibiose regulon. Proc Natl Acad Sci U S A. 1982 Nov;79(22):6971–6975. doi: 10.1073/pnas.79.22.6971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kolesnick R., Golde D. W. The sphingomyelin pathway in tumor necrosis factor and interleukin-1 signaling. Cell. 1994 May 6;77(3):325–328. doi: 10.1016/0092-8674(94)90147-3. [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]
- Leidich S. D., Drapp D. A., Orlean P. A conditionally lethal yeast mutant blocked at the first step in glycosyl phosphatidylinositol anchor synthesis. J Biol Chem. 1994 Apr 8;269(14):10193–10196. [PubMed] [Google Scholar]
- Lester R. L., Dickson R. C. Sphingolipids with inositolphosphate-containing head groups. Adv Lipid Res. 1993;26:253–274. [PubMed] [Google Scholar]
- Lester R. L., Wells G. B., Oxford G., Dickson R. C. Mutant strains of Saccharomyces cerevisiae lacking sphingolipids synthesize novel inositol glycerophospholipids that mimic sphingolipid structures. J Biol Chem. 1993 Jan 15;268(2):845–856. [PubMed] [Google Scholar]
- Lu C. F., Montijn R. C., Brown J. L., Klis F., Kurjan J., Bussey H., Lipke P. N. Glycosyl phosphatidylinositol-dependent cross-linking of alpha-agglutinin and beta 1,6-glucan in the Saccharomyces cerevisiae cell wall. J Cell Biol. 1995 Feb;128(3):333–340. doi: 10.1083/jcb.128.3.333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Megidish T., White T., Takio K., Titani K., Igarashi Y., Hakomori S. The signal modulator protein 14-3-3 is a target of sphingosine- or N,N-dimethylsphingosine-dependent kinase in 3T3(A31) cells. Biochem Biophys Res Commun. 1995 Nov 22;216(3):739–747. doi: 10.1006/bbrc.1995.2684. [DOI] [PubMed] [Google Scholar]
- Merrill A. H., Jr Cell regulation by sphingosine and more complex sphingolipids. J Bioenerg Biomembr. 1991 Feb;23(1):83–104. doi: 10.1007/BF00768840. [DOI] [PubMed] [Google Scholar]
- Nagiec M. M., Baltisberger J. A., Wells G. B., Lester R. L., Dickson R. C. The LCB2 gene of Saccharomyces and the related LCB1 gene encode subunits of serine palmitoyltransferase, the initial enzyme in sphingolipid synthesis. Proc Natl Acad Sci U S A. 1994 Aug 16;91(17):7899–7902. doi: 10.1073/pnas.91.17.7899. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagiec M. M., Wells G. B., Lester R. L., Dickson R. C. A suppressor gene that enables Saccharomyces cerevisiae to grow without making sphingolipids encodes a protein that resembles an Escherichia coli fatty acyltransferase. J Biol Chem. 1993 Oct 15;268(29):22156–22163. [PubMed] [Google Scholar]
- Nuoffer C., Jenö P., Conzelmann A., Riezman H. Determinants for glycophospholipid anchoring of the Saccharomyces cerevisiae GAS1 protein to the plasma membrane. Mol Cell Biol. 1991 Jan;11(1):27–37. doi: 10.1128/mcb.11.1.27. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Olivera A., Spiegel S. Sphingosine-1-phosphate as second messenger in cell proliferation induced by PDGF and FCS mitogens. Nature. 1993 Oct 7;365(6446):557–560. doi: 10.1038/365557a0. [DOI] [PubMed] [Google Scholar]
- Patton J. L., Srinivasan B., Dickson R. C., Lester R. L. Phenotypes of sphingolipid-dependent strains of Saccharomyces cerevisiae. J Bacteriol. 1992 Nov;174(22):7180–7184. doi: 10.1128/jb.174.22.7180-7184.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pinto W. J., Srinivasan B., Shepherd S., Schmidt A., Dickson R. C., Lester R. L. Sphingolipid long-chain-base auxotrophs of Saccharomyces cerevisiae: genetics, physiology, and a method for their selection. J Bacteriol. 1992 Apr;174(8):2565–2574. doi: 10.1128/jb.174.8.2565-2574.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Popolo L., Vai M., Gatti E., Porello S., Bonfante P., Balestrini R., Alberghina L. Physiological analysis of mutants indicates involvement of the Saccharomyces cerevisiae GPI-anchored protein gp115 in morphogenesis and cell separation. J Bacteriol. 1993 Apr;175(7):1879–1885. doi: 10.1128/jb.175.7.1879-1885.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Puoti A., Desponds C., Conzelmann A. Biosynthesis of mannosylinositolphosphoceramide in Saccharomyces cerevisiae is dependent on genes controlling the flow of secretory vesicles from the endoplasmic reticulum to the Golgi. J Cell Biol. 1991 May;113(3):515–525. doi: 10.1083/jcb.113.3.515. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rothstein R. Targeting, disruption, replacement, and allele rescue: integrative DNA transformation in yeast. Methods Enzymol. 1991;194:281–301. doi: 10.1016/0076-6879(91)94022-5. [DOI] [PubMed] [Google Scholar]
- Schwarz A., Rapaport E., Hirschberg K., Futerman A. H. A regulatory role for sphingolipids in neuronal growth. Inhibition of sphingolipid synthesis and degradation have opposite effects on axonal branching. J Biol Chem. 1995 May 5;270(18):10990–10998. doi: 10.1074/jbc.270.18.10990. [DOI] [PubMed] [Google Scholar]
- Sikorski R. S., Hieter P. A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. Genetics. 1989 May;122(1):19–27. doi: 10.1093/genetics/122.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Simons K., van Meer G. Lipid sorting in epithelial cells. Biochemistry. 1988 Aug 23;27(17):6197–6202. doi: 10.1021/bi00417a001. [DOI] [PubMed] [Google Scholar]
- Stevens T., Esmon B., Schekman R. Early stages in the yeast secretory pathway are required for transport of carboxypeptidase Y to the vacuole. Cell. 1982 Sep;30(2):439–448. doi: 10.1016/0092-8674(82)90241-0. [DOI] [PubMed] [Google Scholar]
- Takeda J., Kinoshita T. GPI-anchor biosynthesis. Trends Biochem Sci. 1995 Sep;20(9):367–371. doi: 10.1016/s0968-0004(00)89078-7. [DOI] [PubMed] [Google Scholar]
- Vai M., Popolo L., Grandori R., Lacanà E., Alberghina L. The cell cycle modulated glycoprotein GP115 is one of the major yeast proteins containing glycosylphosphatidylinositol. Biochim Biophys Acta. 1990 May 8;1038(3):277–285. doi: 10.1016/0167-4838(90)90237-a. [DOI] [PubMed] [Google Scholar]
- Wells G. B., Lester R. L. The isolation and characterization of a mutant strain of Saccharomyces cerevisiae that requires a long chain base for growth and for synthesis of phosphosphingolipids. J Biol Chem. 1983 Sep 10;258(17):10200–10203. [PubMed] [Google Scholar]
- Wuestehube L. J., Schekman R. W. Reconstitution of transport from endoplasmic reticulum to Golgi complex using endoplasmic reticulum-enriched membrane fraction from yeast. Methods Enzymol. 1992;219:124–136. doi: 10.1016/0076-6879(92)19015-x. [DOI] [PubMed] [Google Scholar]
- van Echten G., Sandhoff K. Ganglioside metabolism. Enzymology, Topology, and regulation. J Biol Chem. 1993 Mar 15;268(8):5341–5344. [PubMed] [Google Scholar]
- van der Vaart J. M., Caro L. H., Chapman J. W., Klis F. M., Verrips C. T. Identification of three mannoproteins in the cell wall of Saccharomyces cerevisiae. J Bacteriol. 1995 Jun;177(11):3104–3110. doi: 10.1128/jb.177.11.3104-3110.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]