REGULATION OF PHOSPHATE METABOLISM IN NEUROSPORA CRASSA: ISOLATION OF MUTANTS DEFICIENT IN THE REPRESSIBLE ALKALINE PHOSPHATASE

ABSTRACT Five additional mutants of Neurospora crassa have been isolated that lack the repressible alkaline phosphatase. The mutations in these strains map at a previously assigned locus on Linkage Group V designated pho-2 (Gleason and Metzenberg 1974). The five new mutants, as well as three previously isolated by Gleason and Metzenberg (1974), were examined for the presence of cross-reacting material to antibody prepared against purified wild-type enzyme. Two of the mutants produced high levels of cross-reacting material, thus providing evidence that the pho-2 locus includes the structural gene for the repressible alkaline phosphatase. Two revertants were obtained from one of the mutants that contained cross-reacting material. Neither revertant produced an enzyme that could be distinguished physicochemically from that of wild type. A method for measuring very low levels of repressible alkaline phosphatase in crude extracts is also described.

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Structural gene for ornithine decarboxylase in Neurospora crassa

Molecular and Cellular Biology ◽

10.1128/mcb.5.6.1301-1306.1985 ◽

1985 ◽

Vol 5 (6) ◽

pp. 1301-1306

Author(s):

P Eversole ◽

J J DiGangi ◽

T Menees ◽

R H Davis

Keyword(s):

Linkage Group ◽

Neurospora Crassa ◽

Ornithine Decarboxylase ◽

Structural Gene ◽

Minimal Medium ◽

Temperature Sensitive ◽

Wild Type ◽

Wild Type Enzyme ◽

Group V

To define the structural gene for ornithine decarboxylase (ODC) in Neurospora crassa, we sought mutants with kinetically altered enzyme. Four mutants, PE4, PE7, PE69, and PE85, were isolated. They were able to grow slowly at 25 degrees C on minimal medium but required putrescine or spermidine supplementation for growth at 35 degrees C. The mutants did not complement with one another or with ODC-less spe-1 mutants isolated in earlier studies. In all of the mutants isolated to date, the mutations map at the spe-1 locus on linkage group V. Strains carrying mutations PE4, PE7, and PE85 displayed a small amount of residual ODC activity in extracts. None of them had a temperature-sensitive enzyme. The enzyme of the PE85 mutant had a 25-fold higher Km for ornithine (5mM) than did the enzyme of wild-type or the PE4 mutant (ca. 0.2 mM). The enzyme of this mutant was more stable to heat than was the wild-type enzyme. These characteristics were normal in the mutant carrying allele PE4. The mutant carrying PE85 was able to grow well at 25 degrees C and weakly at 35 degrees C with ornithine supplementation. This mutant and three ODC-less mutants isolated previously displayed a polypeptide corresponding to ODC in Western immunoblots with antibody raised to purified wild-type ODC. We conclude that spe-1 is the structural gene for the ODC.

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Structural gene for ornithine decarboxylase in Neurospora crassa.

Molecular and Cellular Biology ◽

10.1128/mcb.5.6.1301 ◽

1985 ◽

Vol 5 (6) ◽

pp. 1301-1306 ◽

Cited By ~ 11

Author(s):

P Eversole ◽

J J DiGangi ◽

T Menees ◽

R H Davis

Keyword(s):

Linkage Group ◽

Neurospora Crassa ◽

Ornithine Decarboxylase ◽

Structural Gene ◽

Minimal Medium ◽

Temperature Sensitive ◽

Wild Type ◽

Wild Type Enzyme ◽

Group V

To define the structural gene for ornithine decarboxylase (ODC) in Neurospora crassa, we sought mutants with kinetically altered enzyme. Four mutants, PE4, PE7, PE69, and PE85, were isolated. They were able to grow slowly at 25 degrees C on minimal medium but required putrescine or spermidine supplementation for growth at 35 degrees C. The mutants did not complement with one another or with ODC-less spe-1 mutants isolated in earlier studies. In all of the mutants isolated to date, the mutations map at the spe-1 locus on linkage group V. Strains carrying mutations PE4, PE7, and PE85 displayed a small amount of residual ODC activity in extracts. None of them had a temperature-sensitive enzyme. The enzyme of the PE85 mutant had a 25-fold higher Km for ornithine (5mM) than did the enzyme of wild-type or the PE4 mutant (ca. 0.2 mM). The enzyme of this mutant was more stable to heat than was the wild-type enzyme. These characteristics were normal in the mutant carrying allele PE4. The mutant carrying PE85 was able to grow well at 25 degrees C and weakly at 35 degrees C with ornithine supplementation. This mutant and three ODC-less mutants isolated previously displayed a polypeptide corresponding to ODC in Western immunoblots with antibody raised to purified wild-type ODC. We conclude that spe-1 is the structural gene for the ODC.

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REGULATION OF PHOSPHATE METABOLISM IN NEUROSPORA CRASSA. CHARACTERIZATION OF REGULATORY MUTANTS

Genetics ◽

10.1093/genetics/75.1.61 ◽

1973 ◽

Vol 75 (1) ◽

pp. 61-73

Author(s):

John F Lehman ◽

Mary K Gleason ◽

Sandra K Ahlgren ◽

Robert L Metzenberg

Keyword(s):

Alkaline Phosphatase ◽

Neurospora Crassa ◽

Control Systems ◽

Double Mutant ◽

Phosphorus Metabolism ◽

Phosphate Metabolism ◽

Wild Type Allele ◽

Wild Type ◽

High Affinity

ABSTRACT A mutant of Neurospora crassa, called UW-6, differs from wild type in being partially constitutive for synthesis of a species of alkaline phosphatase, and also for a species of phosphate permease that has a high affinity for phosphate at high pH. UW-6 is possibly allelic with a mutant called nuc-2 that was previously isolated by Ishikawa. nuc-2 has the converse phenotype, in that it cannot be derepressed for either of these two activities. UW-6 is co-dominant with its wild-type allele in heterokaryons and in partial diploids. An unlinked mutant, nuc-1, is like nuc-2 in that it fails to make the alkaline phosphatase or the permease referred to above. nuc-1 is epistatic to UW-6 in the double mutant. The control of phosphorus metabolism is discussed, and is compared with some other control systems in filamentous fungi.

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Genetic analysis of the phosphatases in Aspergillus nidulans

Genetics Research ◽

10.1017/s0016672300003943 ◽

1965 ◽

Vol 6 (1) ◽

pp. 13-26 ◽

Cited By ~ 92

Author(s):

G. Dorn

Keyword(s):

Alkaline Phosphatase ◽

Acid Phosphatase ◽

Genetic Analysis ◽

Aspergillus Nidulans ◽

Alkaline Ph ◽

Wild Type ◽

Linkage Groups ◽

Partial Restoration ◽

Suppressor Mutations ◽

Alkaline And Acid Phosphatase

Summary1. A histochemical method has been applied to the detection of alkaline and acid phosphatase mutants in single colonies of Aspergillus nidulans.2. With the above method it has been possible to isolate mutants in which the alkaline and acid phosphatase activities are affected either separately or simultaneously.3. Crude extracts of wild-type A. nidulans contain four electrophoretically distinct phosphatase components, two with activity at alkaline pH and two with activity at acid pH. Genes affecting three of the four components have been identified.4. Two suppressor mutants of an alkaline phosphataseless mutant (palB7) have been isolated. In a strain carrying palB7 and one of these suppressors, the restoration of an alkaline phosphatase component is accompanied by loss of the faster acid phosphatase component. In a similar strain carrying the other suppressor, the partial restoration of the alkaline phosphatase component goes with an electrophoretic alteration of the slower acid phosphatase component.5. Genetic analysis of twenty-seven mutants has resulted in the identification of fifteen loci affecting the phosphatases. All these loci have been assigned to linkage groups, and twelve of them were also mapped meiotically in relation to other loci.6. One possible model (based on heteropolymeric proteins) has been proposed to account for the electrophoretic and genetic data on the various phosphatase and suppressor mutations.

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Properties of Repressible Alkaline Phosphatase from Wild Type and a Wall-less Mutant of Neurospora crassa

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)42374-0 ◽

1974 ◽

Vol 249 (15) ◽

pp. 4679-4688

Author(s):

Earl G. Burton ◽

Robert L. Metzenberg

Keyword(s):

Alkaline Phosphatase ◽

Neurospora Crassa ◽

Wild Type

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COMPLEMENTATION ANALYSIS OF LINKED CIRCADIAN CLOCK MUTANTS OF NEUROSPORA CRASSA

Genetics ◽

10.1093/genetics/82.1.9 ◽

1976 ◽

Vol 82 (1) ◽

pp. 9-17 ◽

Cited By ~ 3

Author(s):

Jerry F Feldman ◽

Marian N Hoyle

Keyword(s):

Linkage Group ◽

Circadian Clock ◽

Neurospora Crassa ◽

Period Length ◽

Complementation Analysis ◽

Wild Type ◽

The Right

ABSTRACT A fourth mutant of Neurospora crassa, designated frq-4, has been isolated in which the period length of the circadian conidiation rhythm is shortened to 19.3 ± 0.3 hours. This mutant is tightly linked to the three previously isolated frq mutants, and all four map to the right arm of linkage group VII about 10 map units from the centromere. Complementation tests suggest, but do not prove, that all four mutations are allelic, since each of the four mutants is co-dominant with the frq + allele—i.e., heterokaryons have period lengths intermediate between the mutant and wild-type—and since heterokaryons between pairs of mutants also have period lengths intermediate between those of the two mutants.

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Isolation of telomere DNA from Neurospora crassa

Molecular and Cellular Biology ◽

10.1128/mcb.7.9.3168-3177.1987 ◽

1987 ◽

Vol 7 (9) ◽

pp. 3168-3177

Author(s):

M G Schechtman

Keyword(s):

Linkage Group ◽

Neurospora Crassa ◽

Genetic Background ◽

Type Strain ◽

Wild Type Strain ◽

The Other ◽

Wild Type ◽

Oak Ridge ◽

Entire Chromosome ◽

Different Genetic Background

The most distal known gene on Neurospora crassa linkage group VR, his-6, was cloned. A genomic walk resulted in isolation of the telomere at VR. It was obtained from a library in which the endmost nucleotides of the chromosome had not been removed by nuclease treatment before being cloned, and mapping indicates that the entire chromosome end has probably been cloned. Sequences homologous to the terminal 2.5 kilobases of DNA from VR from these Oak Ridge N. crassa strains are found at other sites in the genome. To characterize these sites, I crossed an Oak Ridge-derived his-6 strain with a wild-type strain of different genetic background (Mauriceville) and characterized the hybridization patterns seen in the progeny. It appears that the sequences homologous to the VR terminus are found at genetically different sites in the two parental strains, and no hybridization to the VR telomere from Mauriceville was detected. The other genomic copies identified in the Oak Ridge parent were not telomeres. I suggest that any repeating sequence blocks found immediately adjacent to the VR terminus in Oak Ridge strains must be small and that the repeating element identified in that background may be an N. crassa transposable element integrated near the the chromosome end at VR.

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