INOSITOL MUTANTS OF SACCHAROMYCES CEREVISIAE: MAPPING THE ino1 LOCUS AND CHARACTERIZING ALLELES OF THE ino1, ino2 AND ino4 LOCI

1 Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York
2 Department of Genetics and Molecular Biology, Albert Einstein College of Medicine, New York, New York

An extensive genetic analysis of inositol auxotrophic mutants of yeast is reported. The analysis includes newly isolated mutants, as well as those previously reported (Culbertson and Henry 1975). Approximately 70% of all inositol auxotrophs isolated are shown to be alleles of the ino1 locus, the structural gene for inositol-1-phosphate synthase, the major enzyme involved in inositol biosynthesis. Alleles of two other loci, ino2 and ino4, comprise 9% of total mutants, with the remainder representing unique loci or complementation groups. The ino1 locus was mapped by trisomic analysis with an n + 1 disomic strain constructed with complementing alleles at this locus. The ino1 locus is shown to be located between ura2 (11.1 cm) and cdc6 (21.8 cm) on chromosome X. An extended map of chromosome X of yeast is presented. Unlike most yeast loci, but similar to the his1 locus, the ino1 locus lacks allelic representatives that are suppressible by known suppressors. This finding suggests that premature termination of translation of the ino1 gene product may be incompatible with cell viability.

Submitted on December 3, 1980
Revised on May 19, 1981




This article has been cited by other articles:


Home page
J. Biol. Chem.Home page
G.-S. Han, L. O'Hara, S. Siniossoglou, and G. M. Carman
Characterization of the Yeast DGK1-encoded CTP-dependent Diacylglycerol Kinase
J. Biol. Chem., July 18, 2008; 283(29): 20443 - 20453.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
G.-S. Han, W.-I Wu, and G. M. Carman
The Saccharomyces cerevisiae Lipin Homolog Is a Mg2+-dependent Phosphatidate Phosphatase Enzyme
J. Biol. Chem., April 7, 2006; 281(14): 9210 - 9218.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
Q. Ouyang, M. Ruiz-Noriega, and S. A. Henry
The REG1 Gene Product Is Required for Repression of INO1 and Other Inositol-Sensitive Upstream Activating Sequence-Containing Genes of Yeast
Genetics, May 1, 1999; 152(1): 89 - 100.
[Abstract] [Full Text]


Home page
J. Biol. Chem.Home page
H. Shen and W. Dowhan
Regulation of Phospholipid Biosynthetic Enzymes by the Level of CDP-Diacylglycerol Synthase Activity
J. Biol. Chem., April 25, 1997; 272(17): 11215 - 11220.
[Abstract] [Full Text] [PDF]


Home page
Mol. Biol. CellHome page
L. Block-Alper, P. Webster, X. Zhou, L. Supekova, W. H. Wong, P. G. Schultz, and D. I. Meyer
IN02, A Positive Regulator of Lipid Biosynthesis, Is Essential for the Formation of Inducible Membranes in Yeast
Mol. Biol. Cell, January 1, 2002; 13(1): 40 - 51.
[Abstract] [Full Text] [PDF]