Genetic analysis of the phosphatases in Aspergillus nidulans

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

Genetics ◽

10.1093/genetics/78.2.645 ◽

1974 ◽

Vol 78 (2) ◽

pp. 645-659

Author(s):

Mary K Gleason ◽

Robert L Metzenberg

Keyword(s):

Alkaline Phosphatase ◽

Acid Phosphatase ◽

Linkage Group ◽

Neurospora Crassa ◽

Heat Stability ◽

Phosphate Metabolism ◽

Wild Type ◽

Wild Type Enzyme ◽

Group V ◽

Suppressor Mutations

ABSTRACT Mutants of Neurospora crassa have been isolated that lack the repressible alkaline phosphatase, but, unlike nuc-1 and nuc-2 mutants, are able to make the repressible acid phosphatase and the repressible phosphate permease under conditions of derepression (phosphate deprivation). The new mutants, called pho-2, map in Linkage Group V, and are unlinked to the putative control mutants, nuc-1, nuc-2-pconc, and pregc. Three of the pho-2 mutants do not make detectable amounts of repressible alkaline phosphatase, but the fourth makes about 1% of the level found in wild type. The small amount of alkaline phosphatase made by this strain appears to be qualitatively similar or identical to the wild-type enzyme, as judged by electrophoretic mobility, heat stability, and titration with specific antibody to the wild-type enzyme. Several revertants of this strain have been examined in the same way, and the alkaline phosphatase of these strains also appears to be qualitatively normal. Reversion events can occur at, or near, the pho-2 locus, but also occur in at least two unlinked sites (suppressor mutations). One suppressor maps very close to nuc-1.

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Suppressor Mutations Bypass the Requirement of fluG for Asexual Sporulation and Sterigmatocystin Production in Aspergillus nidulans

Genetics ◽

10.1093/genetics/165.3.1083 ◽

2003 ◽

Vol 165 (3) ◽

pp. 1083-1093

Author(s):

Jeong-Ah Seo ◽

Yajun Guan ◽

Jae-Hyuk Yu

Keyword(s):

Aspergillus Nidulans ◽

Molecular Mechanisms ◽

Dominant Negative ◽

Wild Type ◽

Dominant Mutation ◽

Site Mutation ◽

Asexual Sporulation ◽

Dominant Negative Mutation ◽

Suppressor Mutations ◽

Early Developmental

Abstract Asexual sporulation (conidiation) in the filamentous fungus Aspergillus nidulans requires the early developmental activator fluG. Loss of fluG results in the blockage of both conidiation and production of the mycotoxin sterigmatocystin (ST). To investigate molecular mechanisms of fluG-dependent developmental activation, 40 suppressors of fluG (SFGs) that conidiate without fluG have been isolated and characterized. Genetic analyses showed that an individual suppression is caused by a single second-site mutation, and that all sfg mutations but one are recessive. Pairwise meiotic crosses grouped mutations to four loci, 31 of them to sfgA, 6 of them to sfgB, and 1 each to sfgC and sfgD, respectively. The only dominant mutation, sfgA38, also mapped to the sfgA locus, suggesting a dominant negative mutation. Thirteen sfgA and 1 sfgC mutants elaborated conidiophores in liquid submerged culture, indicating that loss of either of these gene functions not only bypasses fluG function but also results in hyperactive conidiation. While sfg mutants show varying levels of restored conidiation, all recovered the ability to produce ST at near wild-type levels. The fact that at least four loci are defined by recessive sfg mutations indicates that multiple genes negatively regulate conidiation downstream of fluG and that the activity of fluG is required to remove such repressive effects.

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REGULATION OF PHOSPHATE METABOLISM IN NEUROSPORA CRASSA: IDENTIFICATION OF THE STRUCTURAL GENE FOR REPRESSIBLE ACID PHOSPHATASE

Genetics ◽

10.1093/genetics/84.2.183 ◽

1976 ◽

Vol 84 (2) ◽

pp. 183-192

Author(s):

Robert E Nelson ◽

John F Lehman ◽

Robert L Metzenberg

Keyword(s):

Acid Phosphatase ◽

Neurospora Crassa ◽

Structural Gene ◽

Group Iv ◽

Structural Genes ◽

Wild Type ◽

Linkage Groups ◽

Michaelis Constant ◽

The Right

ABSTRACT A mutant of Neurospora crassa with an altered repressible acid phosphatase has been isolated. The enzyme is much more thermolabile than that of wild type, and has an increased Michaelis constant. Tests of allelic interactions (in partial diploids) and in vitro mixing experiments were consistent with the mutation being in the structural gene for the enzyme. This gene, pho-3, was found to be located in the right arm of Linkage Group IV (LG IV). Thus, pho-3 and the structural gene for repressible alkaline phosphatase, pho-2 (LG V), map in separate linkage groups and cannot be part of the same operon. Neither of these structural genes is linked to the known regulatory genes, nuc-1 (LG I), nuc-2 (LG II), and preg (LG II).

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Suppressor mutations for crs mutants of Bacillus subtilis

Canadian Journal of Microbiology ◽

10.1139/m85-080 ◽

1985 ◽

Vol 31 (5) ◽

pp. 429-435 ◽

Cited By ~ 4

Author(s):

D. Sun ◽

I. Takahashi

Keyword(s):

Alkaline Phosphatase ◽

Bacillus Subtilis ◽

Resistance Gene ◽

Resistance Mutation ◽

Suppressor Mutation ◽

Wild Type ◽

Erythromycin Resistance ◽

Wild Type Level ◽

Suppressor Mutations ◽

Metabolic Activities

Mutants of Bacillus subtilis which carried suppressor mutations for catabolite-resistance gene crsA47 were isolated from methylmethanesulfonate-treated cultures of GLU-47 (crsA47). The suppressor mutation, sca19, suppressed resistance of crsA47 mutant to glucose and other inhibitors of sporulation. Moreover, the suppressor mutation could restore the rate of growth and the level of IMP dehydrogenase and alkaline phosphatase of crsA47 mutant to the wild-type level. The sca19 mutation was also able to suppress catabolite resistance of other crs mutants. The map position of the sea19 mutation indicated that this mutation was an intergenic suppressor for the crs mutants. It was also found that an erythromycin-resistance mutation, ery1, could suppress the catabolite resistance of some of the crs mutants. Our results were discussed in relation to the importance of a proper state of metabolic activities and membrane functions during the initiation of sporulation.

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ALKALINE AND ACID PHOSPHATASE IN CEREBROSPINAL FLUID: DATA FOR NORMAL FLUIDS AND FLUIDS FROM PATIENTS WITH MENINGITIS, POLIOMYELITIS, OR SYPHILIS

Canadian Journal of Research ◽

10.1139/cjr50e-011 ◽

1950 ◽

Vol 28e (2) ◽

pp. 56-68 ◽

Cited By ~ 13

Author(s):

K. G. Colling ◽

R. J. Rossiter

Keyword(s):

Alkaline Phosphatase ◽

Acid Phosphatase ◽

Blood Plasma ◽

Cell Count ◽

Phosphatase Activity ◽

Alkaline Phosphatase Activity ◽

Protein Concentration ◽

White Cell Count ◽

Polymorphonuclear Leucocytes ◽

Alkaline And Acid Phosphatase

Many normal cerebrospinal fluids contain an alkaline (pH 9.8) and an acid (pH 4.9) phosphatase. Both the alkaline and the acid phosphatase were significantly increased in the spinal fluids from patients with meningitis or poliomyelitis, but not in the fluids from patients with syphilis. The alkaline phosphatase activity was correlated with both the concentration of protein in the spinal fluid and with the white cell count, whereas the acid phosphatase was correlated with neither. When correction was made for the significant correlation between cell count and protein concentration, the partial correlation between alkaline phosphatase activity and both protein concentration and cell count remained significant statistically. In pathological conditions it appears likely that the alkaline phosphatase is derived partly from the polymorphonuclear leucocytes in the fluid and partly from the blood plasma. The acid phosphatase is probably derived from the lymphocytes of the fluid and possibly also from the blood plasma. It is unlikely that either of these enzymes comes from the substance of the brain or spinal cord. Acid phosphatase would be of more value than alkaline phosphatase as a diagnostic aid, since normal fluids contain much less of this enzyme.

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Structural genes for phosphatases inAspergillus nidulans

Genetics Research ◽

10.1017/s0016672300022904 ◽

1986 ◽

Vol 47 (2) ◽

pp. 83-91 ◽

Cited By ~ 43

Author(s):

Mark X. Caddick ◽

Herbert N. Arst

Keyword(s):

Alkaline Phosphatase ◽

Acid Phosphatase ◽

Aspergillus Nidulans ◽

Structural Gene ◽

Essential Role ◽

Thermal Inactivation ◽

Sufficient Conditions ◽

Structural Genes ◽

Electrophoretic Patterns ◽

Staining Techniques

SUMMARYAlthough the fungusAspergillus nidulanshas a multiplicity of phosphatases and of genes where mutations affect one or more phosphatases, we have succeeded in identifying structural genes for three phosphatases as well as one other gene which might encode a fourth. Using both conditional and non-conditional mutations,palD has been shown to be the structural gene for a phosphate-repressible alkaline phosphatase,palG to be the structural gene for a non-repressible alkaline phosphatase which apparently exists in two electrophoretically distinct forms (but whose rates of thermal inactivation are apparently very similar) andpacA to be the structural gene for both intracellular and secreted forms of a phosphate-repressible acid phosphatase. Colony staining techniques for the enzymes specified bypalD andpacA have been described previously but we have now shown that the enzyme specified bypalG can be detected by staining toluene-permeabilized colonies. Mutations inpacG lead to loss of non-repressible acid phosphatase as judged by colony staining and electrophoretic patterns but their effects on assays of activity in cell-free extracts are only marginal. Under phosphate-limited, but not phosphate-starved or phosphate-sufficient, conditions,pacG−mutations also affect the regulation of other, phosphate-repressible phosphatases. None of these phosphatases, alone or in combination, plays an essential role.

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Genetic Analysis of Flagellar Length Control in Chlamydomonas reinhardtii: A New Long-Flagella Locus and Extragenic Suppressor Mutations

Genetics ◽

10.1093/genetics/148.2.693 ◽

1998 ◽

Vol 148 (2) ◽

pp. 693-702

Author(s):

Catherine M Asleson ◽

Paul A Lefebvre

Keyword(s):

Genetic Analysis ◽

Chlamydomonas Reinhardtii ◽

Double Mutant ◽

Wild Type ◽

Suppressor Mutations ◽

Extragenic Suppressor ◽

Flagellar Regeneration

Abstract Flagellar length in the biflagellate alga Chlamydomonas reinhardtii is under constant and tight regulation. A number of mutants with defects in flagellar length control have been previously identified. Mutations in the three long-flagella (lf) loci result in flagella that are up to three times longer than wild-type length. In this article, we describe the isolation of long-flagellar mutants caused by mutations in a new LF locus, LF4. lf4 mutations were shown to be epistatic to lf1, while lf2 was found to be epistatic to lf4 with regard to the flagellar regeneration defect. Mutations in lf4 were able to suppress the synthetic flagella-less phenotype of the lf1, lf2 double mutant. In addition, we have isolated four extragenic suppressor mutations that suppress the long-flagella phenotype of lf1, lf2, or lf3 double mutants.

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Acid and Alkaline Phosphatase Activity in Axenically Grown Physarum Myxamoebae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600002129 ◽

1980 ◽

Vol 38 ◽

pp. 488-489

Author(s):

Henry C. Aldrich

Keyword(s):

Alkaline Phosphatase ◽

Acid Phosphatase ◽

Mammalian Cells ◽

Cellular Localization ◽

Plasma Membranes ◽

Cell Fractionation ◽

Intact Cells ◽

E Coli ◽

Food Vacuoles ◽

Alkaline And Acid Phosphatase

In preparation for biochemical studies of isolated plasma membranes of myxamoebae of the mycetozoan Physarum polycephalum, histochemical studies were undertaken to determine the cellular localization of alkaline and acid phosphatase activities. In a previous paper, Kazama and Aldrich1 showed that myxamoebae of Physarum, when grown with E. coli as the food source, synthesize acid phosphatase in Golgi apparatus and utilize it in food vacuoles in the process of bacterial digestion. There are no data, however, regarding whether myxamoebae grown on an axenic medium secrete and sequester acid phosphatase within the food vacuoles. One purpose of this study was to answer this question. Secondly, alkaline phosphatase is a commonly used marker for plasma membranes in mammalian cells and is often employed in cell fractionation studies. Its presence in plasma membranes of Physarum myxamoebae has not been demonstrated, so the study reported here was also designed to see whether alkaline phosphatase occurs in these intact cells, and if so, where.

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Genetic analysis of an unequal chromosomal translocation in Aspergillus nidulans

Genetics Research ◽

10.1017/s001667230000166x ◽

1970 ◽

Vol 15 (3) ◽

pp. 317-326 ◽

Cited By ~ 8

Author(s):

B. W. Bainbridge

Keyword(s):

Linkage Group ◽

Genetic Analysis ◽

Aspergillus Nidulans ◽

Genetic Markers ◽

Chromosomal Translocation ◽

Group Viii ◽

Linkage Groups ◽

Group Iii ◽

Attachment Point ◽

Breakage Point

SUMMARYTranslocation T(III–VIII) in Aspergillus nidulans has been analysed by the detection of meiotic linkage between markers previously located separately on linkage groups III and VIII. The breakage points have been mapped by the detection of linkage between the crinkled type and genetic markers in the region of the break. A segment from linkage group III, approximately 43 units long and including the markers moC96, sC12, sA1 and cnxH3, has been translocated into linkage group VIII. The breakage point is between su6proA and moC96 and the attachment point is close to cha in linkage group VIII. It seems probable that the segment has been inserted into linkage group VIII.

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Mutations in sfdA and sfdB Suppress Multiple Developmental Mutations in Aspergillus nidulans

Genetics ◽

10.1093/genetics/160.1.159 ◽

2002 ◽

Vol 160 (1) ◽

pp. 159-168

Author(s):

Ellen M Kellner ◽

Thomas H Adams

Keyword(s):

Aspergillus Nidulans ◽

Null Allele ◽

Hyphal Growth ◽

Loss Of Function ◽

Wild Type ◽

Regulatory Pathway ◽

Submerged Cultures ◽

Developmental Defects ◽

Suppressor Mutations ◽

Its Gene

Abstract Conidiophore morphogenesis in Aspergillus nidulans occurs in response to developmental signals that result in the activation of brlA, a well-characterized gene that encodes a transcription factor that is central to asexual development. Loss-of-function mutations in flbD and other fluffy loci have previously been shown to result in delayed development and reduced expression of brlA. flbD message is detectable during both hyphal growth and conidiation, and its gene product is similar to the Myb family of transcription factors. To further understand the regulatory pathway to brlA activation and conidiation, we isolated suppressor mutations that rescued development in strains with a flbD null allele. We describe here two new loci, designated sfdA and sfdB for suppressors of flbD, that bypass the requirement of flbD for development. sfd mutant alleles were found to restore developmental timing and brlA expression to strains with flbD deletions. In addition, sfd mutations suppress the developmental defects in strains harboring loss-of-function mutations in fluG, flbA, flbB, flbC, and flbE. All alleles of sfdA and sfdB that we have isolated are recessive to their wild-type alleles in diploids. Strains with mutant sfd alleles in otherwise developmentally wild-type backgrounds have reduced growth phenotypes and develop conidiophores in submerged cultures.

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