Abstract
The Saccharomyces cerevisiae FLO1 gene encodes a large 1,536-amino-acid serine- and threonine-rich protein involved in flocculation. We have assessed the localization of Flo1p by immunoelectron microscopy, and in this study we show that this protein is located in the external mannoprotein layer of the cell wall, at the plasma membrane level and in the periplasm. The protein was also visualized in the endoplasmic reticulum and in the nuclear envelope, indicating that it was secreted through the secretory pathway. The protein was detected by Western blotting in cell wall extracts as a high-molecular-mass (>200 kDa) polydisperse material obviously as a result of extensive N and probably O glycosylation. Flo1p was extracted from cell walls in large amounts by boiling in sodium dodecyl sulfate, suggesting that it is noncovalently anchored to the cell wall network. The membranous forms of Flo1p were shown to be solubilized by phosphatidylinositol-phospholipase C treatment, suggesting that Flo1p is glycosyl phosphatidylinositol (GPI) anchored to this organelle. The expression of truncated forms with the hydrophobic C-terminal domain deleted led to the secretion of the protein in the culture medium. The hydrophobic C terminus, which is a putative GPI anchoring domain, is therefore necessary for the attachment of Flo1p in the cell wall. Deletion analysis also revealed that the N-terminal domain of Flo1p was essential for cellular aggregation. On the whole, our data indicate that Flo1p is a true cell wall protein which plays a direct role in cell-cell interaction.
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- Bidard F., Blondin B., Dequin S., Vezinhet F., Barre P. Cloning and analysis of a FLO5 flocculation gene from S. cerevisiae. Curr Genet. 1994 Mar;25(3):196–201. doi: 10.1007/BF00357162. [DOI] [PubMed] [Google Scholar]
- Bidard F., Bony M., Blondin B., Dequin S., Barre P. The Saccharomyces cerevisiae FLO1 flocculation gene encodes for a cell surface protein. Yeast. 1995 Jul;11(9):809–822. doi: 10.1002/yea.320110903. [DOI] [PubMed] [Google Scholar]
- Bussey H., Kaback D. B., Zhong W., Vo D. T., Clark M. W., Fortin N., Hall J., Ouellette B. F., Keng T., Barton A. B. The nucleotide sequence of chromosome I from Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 1995 Apr 25;92(9):3809–3813. doi: 10.1073/pnas.92.9.3809. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Christianson T. W., Sikorski R. S., Dante M., Shero J. H., Hieter P. Multifunctional yeast high-copy-number shuttle vectors. Gene. 1992 Jan 2;110(1):119–122. doi: 10.1016/0378-1119(92)90454-w. [DOI] [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]
- Elorza M. V., Marcilla A., Sentandreu R. Wall mannoproteins of the yeast and mycelial cells of Candida albicans: nature of the glycosidic bonds and polydispersity of their mannan moieties. J Gen Microbiol. 1988 Aug;134(8):2393–2403. doi: 10.1099/00221287-134-8-2393. [DOI] [PubMed] [Google Scholar]
- Ferguson M. A., Williams A. F. Cell-surface anchoring of proteins via glycosyl-phosphatidylinositol structures. Annu Rev Biochem. 1988;57:285–320. doi: 10.1146/annurev.bi.57.070188.001441. [DOI] [PubMed] [Google Scholar]
- Jentoft N. Why are proteins O-glycosylated? Trends Biochem Sci. 1990 Aug;15(8):291–294. doi: 10.1016/0968-0004(90)90014-3. [DOI] [PubMed] [Google Scholar]
- Johnston M., Andrews S., Brinkman R., Cooper J., Ding H., Dover J., Du Z., Favello A., Fulton L., Gattung S. Complete nucleotide sequence of Saccharomyces cerevisiae chromosome VIII. Science. 1994 Sep 30;265(5181):2077–2082. doi: 10.1126/science.8091229. [DOI] [PubMed] [Google Scholar]
- Kapteyn J. C., Montijn R. C., Vink E., de la Cruz J., Llobell A., Douwes J. E., Shimoi H., Lipke P. N., Klis F. M. Retention of Saccharomyces cerevisiae cell wall proteins through a phosphodiester-linked beta-1,3-/beta-1,6-glucan heteropolymer. Glycobiology. 1996 Apr;6(3):337–345. doi: 10.1093/glycob/6.3.337. [DOI] [PubMed] [Google Scholar]
- Klis F. M. Review: cell wall assembly in yeast. Yeast. 1994 Jul;10(7):851–869. doi: 10.1002/yea.320100702. [DOI] [PubMed] [Google Scholar]
- Lu C. F., Kurjan J., Lipke P. N. A pathway for cell wall anchorage of Saccharomyces cerevisiae alpha-agglutinin. Mol Cell Biol. 1994 Jul;14(7):4825–4833. doi: 10.1128/mcb.14.7.4825. [DOI] [PMC free article] [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]
- Miki B. L., Poon N. H., James A. P., Seligy V. L. Possible mechanism for flocculation interactions governed by gene FLO1 in Saccharomyces cerevisiae. J Bacteriol. 1982 May;150(2):878–889. doi: 10.1128/jb.150.2.878-889.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nuoffer C., Horvath A., Riezman H. Analysis of the sequence requirements for glycosylphosphatidylinositol anchoring of Saccharomyces cerevisiae Gas1 protein. J Biol Chem. 1993 May 15;268(14):10558–10563. [PubMed] [Google Scholar]
- Preuss D., Mulholland J., Kaiser C. A., Orlean P., Albright C., Rose M. D., Robbins P. W., Botstein D. Structure of the yeast endoplasmic reticulum: localization of ER proteins using immunofluorescence and immunoelectron microscopy. Yeast. 1991 Dec;7(9):891–911. doi: 10.1002/yea.320070902. [DOI] [PubMed] [Google Scholar]
- Shankar C. S., Umesh-Kumar S. A surface lectin associated with flocculation in brewing strains of Saccharomyces cerevisiae. Microbiology. 1994 May;140(Pt 5):1097–1101. doi: 10.1099/13500872-140-5-1097. [DOI] [PubMed] [Google Scholar]
- Stratford M. Another brick in the wall? Recent developments concerning the yeast cell envelope. Yeast. 1994 Dec;10(13):1741–1752. doi: 10.1002/yea.320101307. [DOI] [PubMed] [Google Scholar]
- Stratford M. Yeast flocculation: reconciliation of physiological and genetic viewpoints. Yeast. 1992 Jan;8(1):25–38. doi: 10.1002/yea.320080103. [DOI] [PubMed] [Google Scholar]
- Straver M. H., Smit G., Kijne J. W. Purification and partial characterization of a flocculin from brewer's yeast. Appl Environ Microbiol. 1994 Aug;60(8):2754–2758. doi: 10.1128/aem.60.8.2754-2758.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Straver M. H., Traas V. M., Smit G., Kijne J. W. Isolation and partial purification of mannose-specific agglutinin from brewer's yeast involved in flocculation. Yeast. 1994 Sep;10(9):1183–1193. doi: 10.1002/yea.320100906. [DOI] [PubMed] [Google Scholar]
- Teunissen A. W., Holub E., van der Hucht J., van den Berg J. A., Steensma H. Y. Sequence of the open reading frame of the FLO1 gene from Saccharomyces cerevisiae. Yeast. 1993 Apr;9(4):423–427. doi: 10.1002/yea.320090413. [DOI] [PubMed] [Google Scholar]
- Teunissen A. W., Steensma H. Y. Review: the dominant flocculation genes of Saccharomyces cerevisiae constitute a new subtelomeric gene family. Yeast. 1995 Sep 15;11(11):1001–1013. doi: 10.1002/yea.320111102. [DOI] [PubMed] [Google Scholar]
- Vernet T., Dignard D., Thomas D. Y. A family of yeast expression vectors containing the phage f1 intergenic region. Gene. 1987;52(2-3):225–233. doi: 10.1016/0378-1119(87)90049-7. [DOI] [PubMed] [Google Scholar]
- Watari J., Takata Y., Ogawa M., Sahara H., Koshino S., Onnela M. L., Airaksinen U., Jaatinen R., Penttilä M., Keränen S. Molecular cloning and analysis of the yeast flocculation gene FLO1. Yeast. 1994 Feb;10(2):211–225. doi: 10.1002/yea.320100208. [DOI] [PubMed] [Google Scholar]
- Wojciechowicz D., Lu C. F., Kurjan J., Lipke P. N. Cell surface anchorage and ligand-binding domains of the Saccharomyces cerevisiae cell adhesion protein alpha-agglutinin, a member of the immunoglobulin superfamily. Mol Cell Biol. 1993 Apr;13(4):2554–2563. doi: 10.1128/mcb.13.4.2554. [DOI] [PMC free article] [PubMed] [Google Scholar]
- de Nobel H., Lipke P. N. Is there a role for GPIs in yeast cell-wall assembly? Trends Cell Biol. 1994 Feb;4(2):42–45. doi: 10.1016/0962-8924(94)90003-5. [DOI] [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]