Abstract
We isolated a mutant of Saccharomyces cerevisiae defective in the formation of phosphatidylcholine via methylation of phosphatidylethanolamine. The mutant synthesized phosphatidylcholine at a reduced rate and accumulated increased amounts of methylated phospholipid intermediates. It was also found to be auxotrophic for inositol and allelic to an existing series of ino4 mutants. The ino2 and ino4 mutants, originally isolated on the basis of an inositol requirement, are unable to derepress the cytoplasmic enzyme inositol-1-phosphate synthase (myo-inositol-1-phosphate synthase; EC 5.5.1.4). The INO4 and INO2 genes were, thus, previously identified as regulatory genes whose wild-type product is required for expression of the INO1 gene product inositol-1-phosphate synthase (T. Donahue and S. Henry, J. Biol. Chem. 256:7077-7085, 1981). In addition to the identification of a new ino4-allele, further characterization of the existing series of ino4 and ino2 mutants, reported here, demonstrated that they all have a reduced capacity to convert phosphatidylethanolamine to phosphatidylcholine. The pleiotropic phenotype of the ino2 and ino4 mutants described in this paper suggests that the INO2 and INO4 loci are involved in the regulation of phospholipid methylation in the membrane as well as inositol biosynthesis in the cytoplasm.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Atkinson K. D., Jensen B., Kolat A. I., Storm E. M., Henry S. A., Fogel S. Yeast mutants auxotrophic for choline or ethanolamine. J Bacteriol. 1980 Feb;141(2):558–564. doi: 10.1128/jb.141.2.558-564.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Atkinson K., Fogel S., Henry S. A. Yeast mutant defective in phosphatidylserine synthesis. J Biol Chem. 1980 Jul 25;255(14):6653–6661. [PubMed] [Google Scholar]
- Culbertson M. R., Donahue T. F., Henry S. A. Control of inositol biosynthesis in Saccharomyces cerevisiae: properties of a repressible enzyme system in extracts of wild-type (Ino+) cells. J Bacteriol. 1976 Apr;126(1):232–242. doi: 10.1128/jb.126.1.232-242.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Culbertson M. R., Donahue T. F., Henry S. A. Control of inositol biosynthesis in Saccharomyces cerevisiae; inositol-phosphate synthetase mutants. J Bacteriol. 1976 Apr;126(1):243–250. doi: 10.1128/jb.126.1.243-250.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Culbertson M. R., Henry S. A. Inositol-requiring mutants of Saccharomyces cerevisiae. Genetics. 1975 May;80(1):23–40. doi: 10.1093/genetics/80.1.23. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Donahue T. F., Henry S. A. myo-Inositol-1-phosphate synthase. Characteristics of the enzyme and identification of its structural gene in yeast. J Biol Chem. 1981 Jul 10;256(13):7077–7085. [PubMed] [Google Scholar]
- FOLCH J., LEES M., SLOANE STANLEY G. H. A simple method for the isolation and purification of total lipides from animal tissues. J Biol Chem. 1957 May;226(1):497–509. [PubMed] [Google Scholar]
- Greenberg M. L., Klig L. S., Letts V. A., Loewy B. S., Henry S. A. Yeast mutant defective in phosphatidylcholine synthesis. J Bacteriol. 1983 Feb;153(2):791–799. doi: 10.1128/jb.153.2.791-799.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Henry S. A., Atkinson K. D., Kolat A. I., Culbertson M. R. Growth and metabolism of inositol-starved Saccharomyces cerevisiae. J Bacteriol. 1977 Apr;130(1):472–484. doi: 10.1128/jb.130.1.472-484.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hinnebusch A. G., Fink G. R. Positive regulation in the general amino acid control of Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 1983 Sep;80(17):5374–5378. doi: 10.1073/pnas.80.17.5374. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KENNEDY E. P., WEISS S. B. The function of cytidine coenzymes in the biosynthesis of phospholipides. J Biol Chem. 1956 Sep;222(1):193–214. [PubMed] [Google Scholar]
- Kovác L., Gbelská I., Poliachová V., Subík J., Kovácová V. Membrane mutants: a yeast mutant with a lesion in phosphatidylserine biosynthesis. Eur J Biochem. 1980 Oct;111(2):491–501. doi: 10.1111/j.1432-1033.1980.tb04965.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]
- Letts V. A., Dawes I. W. Mutations affecting lipid biosynthesis of Saccharomyces cerevisiae: isolation of ethanolamine auxotrophs [proceedings]. Biochem Soc Trans. 1979 Oct;7(5):976–977. doi: 10.1042/bst0070976. [DOI] [PubMed] [Google Scholar]
- Letts V. A., Klig L. S., Bae-Lee M., Carman G. M., Henry S. A. Isolation of the yeast structural gene for the membrane-associated enzyme phosphatidylserine synthase. Proc Natl Acad Sci U S A. 1983 Dec;80(23):7279–7283. doi: 10.1073/pnas.80.23.7279. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lindegren G., Hwang Y. L., Oshima Y., Lindegren C. C. Genetical mutants induced by ethyl methanesulfonate in Saccharomyces. Can J Genet Cytol. 1965 Sep;7(3):491–499. doi: 10.1139/g65-064. [DOI] [PubMed] [Google Scholar]
- Scarborough G. A., Nyc J. F. Methylation of ethanolamine phosphatides by microsomes from normal and mutant strains of Neurospora crassa. J Biol Chem. 1967 Jan 25;242(2):238–242. [PubMed] [Google Scholar]
- Steiner M. R., Lester R. L. In vitro studies of phospholipid biosynthesis in Saccharomyces cerevisiae. Biochim Biophys Acta. 1972 Feb 21;260(2):222–243. doi: 10.1016/0005-2760(72)90035-5. [DOI] [PubMed] [Google Scholar]
- Waechter C. J., Lester R. L. Differential regulation of the N-methyl transferases responsible for phosphatidylcholine synthesis in Saccharomyces cerevisiae. Arch Biochem Biophys. 1973 Sep;158(1):401–410. doi: 10.1016/0003-9861(73)90637-1. [DOI] [PubMed] [Google Scholar]
- Waechter C. J., Lester R. L. Regulation of phosphatidylcholine biosynthesis in Saccharomyces cerevisiae. J Bacteriol. 1971 Mar;105(3):837–843. doi: 10.1128/jb.105.3.837-843.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wolfner M., Yep D., Messenguy F., Fink G. R. Integration of amino acid biosynthesis into the cell cycle of Saccharomyces cerevisiae. J Mol Biol. 1975 Aug 5;96(2):273–290. doi: 10.1016/0022-2836(75)90348-4. [DOI] [PubMed] [Google Scholar]
- Yamashita S., Oshima A., Nikawa J., Hosaka K. Regulation of the phosphatidylethanolamine methylation pathway in Saccharomyces cerevisiae. Eur J Biochem. 1982 Nov 15;128(2-3):589–595. doi: 10.1111/j.1432-1033.1982.tb07005.x. [DOI] [PubMed] [Google Scholar]
- Yamashita S., Oshima A. Regulation of phosphatidylethanolamine methyltransferase level by myo-inositol in Saccaromyces cerevisiae. Eur J Biochem. 1980 Mar;104(2):611–616. doi: 10.1111/j.1432-1033.1980.tb04465.x. [DOI] [PubMed] [Google Scholar]