The Product of the Leu-3 Cistron As a Regulatory Element for the Production of the Leucine Biosynthetic Enzymes of Neurospora

Overview

Journal Genetics

Publisher Oxford University Press

Specialty Genetics

Date 1973 Jul 1

PMID 4744402

Citations 19

Authors

J C Polacco

S R Gross

Affiliations

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Abstract

A class of intracistronic (or closely linked) partial reversions of leu-3 mutations has been found to be conditionally constitutive with respect to the synthesis of isopropylmalate isomerase (specified by the leu-2 cistron) and beta-isopropylmalate dehydrogenase (specified by the leu-1 cistron), two of the enzymes of leucine biosynthesis in Neurospora. The intermediate level of enzyme production by these leu-3(cc) mutants is independent of the obligatory inducer effector, alpha-isopropylmalate, but dependent upon the presence of the branched-chain amino acids, isoleucine, valine and leucine. The properties of leu-3+, leu-3 and leu-3(cc) in heterokaryons indicate that the transnuclear regulatory activity of the leu-3 product varies specifically as a function of available effector molecules. The information presented suggests that the leu-3 cistron is responsible not only for the production of a "positive" regulatory substance necessary for the expression of the leu-1 and leu-2 cistrons, but that it probably serves also a coordinating role in the expression of many of the genes involved in branched-chain amino acid metabolism.

Citing Articles

Leucine biosynthesis in yeast : Identification of two genes (LEU4, LEU5) that affect α-Isopropylmalate synthase activity and evidence that LEU1 and LEU2 gene expression is controlled by α-Isopropylmalate and the product of a regulatory gene.

Baichwal V, Cunningham T, Gatzek P, Kohlhaw G Curr Genet. 2013; 7(5):369-77.

PMID: 24173418 DOI: 10.1007/BF00445877.

Interaction among C, R and Vp in the Control of the Bz Glucosyltransferase during Endosperm Development in Maize.

Dooner H, Nelson O Genetics. 1979; 91(2):309-15.

PMID: 17248885 PMC: 1216368. DOI: 10.1093/genetics/91.2.309.

Leucine biosynthesis in fungi: entering metabolism through the back door.

Kohlhaw G Microbiol Mol Biol Rev. 2003; 67(1):1-15, table of contents.

PMID: 12626680 PMC: 150519. DOI: 10.1128/MMBR.67.1.1-15.2003.

The Saccharomyces cerevisiae Leu3 protein activates expression of GDH1, a key gene in nitrogen assimilation.

Hu Y, Cooper T, Kohlhaw G Mol Cell Biol. 1995; 15(1):52-7.

PMID: 7799961 PMC: 231907. DOI: 10.1128/MCB.15.1.52.

The sequence and binding specificity of UaY, the specific regulator of the purine utilization pathway in Aspergillus nidulans, suggest an evolutionary relationship with the PPR1 protein of Saccharomyces cerevisiae.

Suarez T, de Queiroz M, Oestreicher N, Scazzocchio C EMBO J. 1995; 14(7):1453-67.

PMID: 7729421 PMC: 398233. DOI: 10.1002/j.1460-2075.1995.tb07132.x.

References

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