scholarly journals Phosphatases ofCoprinus lagopus: the conditions for their production and the genetics of the alkaline phosphatase

1971 ◽  
Vol 18 (2) ◽  
pp. 153-166 ◽  
Author(s):  
Jane North ◽  
D. Lewis

SUMMARY1.Coprinus lagopusproduces two non-specific phosphatases: a constitutive acid phosphatase, and an alkaline phosphatase which is repressed during growth on media with a high inorganic phosphate concentration.2. The alkaline phosphatase is also repressed whenCoprinusis grown on an organic phosphate source; but if the acid phosphatase is selectively inhibited by fluoride the alkaline phosphatase is de-repressed and growth is comparable to that observed on an inorganic phosphate source.3. Alkaline phosphatase is not repressed in aerial mycelium or sporophores even when grown on high phosphate medium.4. Mutants altered in their capacity to synthesize alkaline phosphatase were selected from two compatible wild-type strains, H2 and H5.5. Mutants producing a higher level of alkaline phosphatase than wild-type (‘regulator’ mutants) fall into four (or possibly five) complementation groups. Assuming five separate genes, two pairs are linked; the remaining one is independent and on another chromosome.6. Mutants deficient in alkaline phosphatase synthesis fall into at least three groups. They were tested for linkage to ‘regulator’ loci but so far there is no evidence of this.

Genetics ◽  
1982 ◽  
Vol 102 (3) ◽  
pp. 341-359
Author(s):  
Linda F Bisson ◽  
Jeremy Thorner

ABSTRACT Yeast mutants permeable to dTMP (tup) were selected and two new complementation groups (tup5 and tup7) were identified. Assay of the levels of both acid and alkaline phosphatase in cells grown under either repressing (5 mm PO4  -3) or derepressing (0.03 mm PO4  -3) conditions indicated that, in general, tup mutations cause cells to be defective in their regulation of phosphatase synthesis. In addition, three of the tup mutations (tup1, tup4 and tup7) displayed markedly elevated rates of inorganic phosphate transport. The tup7 locus was found to be tightly centromere-linked on the right arm of chromosome XV, and was shown to be allelic with the pho80 regulatory locus on the basis of both genetic and biochemical criteria. Analysis of other mutations known to affect phosphatase levels (pho) indicated that some also conferred permeability to dTMP. Possible allelic relationships between tup genes and certain of these pho mutations are discussed. Regardless of the culture conditions, wild-type strains were not permeable to dTMP; in contrast, it was found in the course of this work that normal yeast cells were permeable to dUMP and that dUMP permeability was regulated by the concentration of inorganic phosphate present in the medium used to grow the cells. Thus, permeability to 5′-mononucleotides appears to be under coordinate control with phosphatase synthesis.


1982 ◽  
Vol 152 (2) ◽  
pp. 692-701
Author(s):  
M Amemura ◽  
H Shinagawa ◽  
K Makino ◽  
N Otsuji ◽  
A Nakata

The regulatory genes of alkaline phosphatase, phoS and phoT, of Escherichia coli were cloned on pBR322, initially as an 11.8-kilobase EcoRI fragment. A restriction map of the hybrid plasmid was established. Deletion plasmids of various sizes were constructed in vitro, and the presence of phoS and phoT genes on the cloned DNA fragments was tested by introducing the plasmids into phoS64 and phoT9 strains for complementation tests. One set complemented only phoS64 but not phoT9; the other set complemented only phoT9 but not phoS64. We conclude that phoS64 and phoT9 mutations belong to different complementation groups and probably to different cistrons. The hybrid plasmid with the 11.8-kilobase chromosomal fragment also complemented the phoT35 mutation. A smaller derivative of the hybrid plasmid was constructed in vitro which complemented phoT35 but did not complement phoS64, phoT9, or pst-2. Our results agree with the suggestion that phoT35 lies in a different complementation group from phoS, phoT, or pst-2 (Zuckier and Torriani, J. Bacteriol. 145:1249--1256, 1981). Therefore, we propose to designate phoT35 as phoU. The effect of amplification of phoS or phoT on alkaline phosphatase production was examined. It was found that multiple copies of the phoS gene borne on pBR322 repressed enzyme production even in low-phosphate medium, whether it was introduced into wild-type strains (partially repressed) or phoR (phoR68 or phoR17) strains (fully repressed), whereas the introduction of multicopy plasmids bearing the phoT gene did not affect the inducibility of the enzyme.


Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Qijun Xiang ◽  
N Louise Glass

AbstractA non-self-recognition system called vegetative incompatibility is ubiquitous in filamentous fungi and is genetically regulated by het loci. Different fungal individuals are unable to form viable heterokaryons if they differ in allelic specificity at a het locus. To identify components of vegetative incompatibility mediated by allelic differences at the het-c locus of Neurospora crassa, we isolated mutants that suppressed phenotypic aspects of het-c vegetative incompatibility. Three deletion mutants were identified; the deletions overlapped each other in an ORF named vib-1 (vegetative incompatibility blocked). Mutations in vib-1 fully relieved growth inhibition and repression of conidiation conferred by het-c vegetative incompatibility and significantly reduced hyphal compartmentation and death rates. The vib-1 mutants displayed a profuse conidiation pattern, suggesting that VIB-1 is a regulator of conidiation. VIB-1 shares a region of similarity to PHOG, a possible phosphate nonrepressible acid phosphatase in Aspergillus nidulans. Native gel analysis of wild-type strains and vib-1 mutants indicated that vib-1 is not the structural gene for nonrepressible acid phosphatase, but rather may regulate nonrepressible acid phosphatase activity.


Genetics ◽  
1975 ◽  
Vol 80 (2) ◽  
pp. 239-250
Author(s):  
R F Matagne ◽  
R Loppes

ABSTRACT In the green alga Chlamydomonas reinhardi, removal of inorganic phosphate from the culture medium results in the increase of phosphatase activity (derepression) in the wild-type (WT) strain as well as in a double mutant (P2Pa) lacking the two main constitutive acid phosphatases. Following treatment of WT and P2Pa with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), mutants were recovered which display very low phosphatase activities when grown in the absence of phosphate; as shown by electrophoresis, they lack one non-migrating phosphatase (PD mutants). This enzyme is active over a wide range of pH with an optimum at pH 7.5. The comparison of electropherograms from WT and mutants grown on media with or without phosphate allowed us to provide a tentative definition of the pool of derepressible phosphatases in Chlamydomonas : in addition to the neutral phosphatase lacking in PD mutants, Chlamydomonas produces two electrophoretic forms of alkaline phosphatase showing an optimal activity at pH 9.5.


Genetics ◽  
1976 ◽  
Vol 82 (3) ◽  
pp. 429-442
Author(s):  
Reed B Wickner ◽  
Michael J Leibowitz

ABSTRACT The killer character of yeast is determined by a 1.4 × 106 molecular weight double-stranded RNA plasmid and at least 12 chromosomal genes. Wild-type strains of yeast that carry this plasmid (killers) secrete a toxin which is lethal only to strains not carrying this plasmid (sensitives). —— We have isolated 28 independent recessive chromosomal mutants of a killer strain that have lost the ability to secrete an active toxin but remain resistant to the effects of the toxin and continue to carry the complete cytoplasmic killer genome. These mutants define two complementation groups, kex1 and kex2. Kex1 is located on chromosome VII between ade5 and lys5. Kex2 is located on chromosome XIV, but it does not show meiotic linkage to any gene previously located on this chromosome. —— When the killer plasmid of kex1 or kex2 strains is eliminated by curing with heat or cycloheximide, the strains become sensitive to killing. The mutant phenotype reappears among the meiotic segregants in a cross with a normal killer. Thus, the kex phenotype does not require an alteration of the killer plasmid. —— Kex1 and kex2 strains each contain near-normal levels of the 1.4 × 106 molecular weight double-stranded RNA, whose presence is correlated with the presence of the killer genome.


1985 ◽  
Vol 5 (1) ◽  
pp. 248-252
Author(s):  
Y Kaneko ◽  
Y Tamai ◽  
A Toh-e ◽  
Y Oshima

A DNA fragment bearing the PHO8 gene, which encodes repressible alkaline phosphatase of Saccharomyces cerevisiae, was cloned. Northern hybridizations with the PHO8 DNA as probe indicated that the PHO8 transcript is 1.8 kilobases in length and is more abundant in cells grown in low-phosphate medium than in high-phosphate medium. The pho9 mutant, whose phenotype is defective in the activity of repressible alkaline phosphatase, produced as much of the PHO8 transcript as did the PHO9+ cells. Hence, the PHO9 product should act at the post-transcriptional level. The pho4 mutant could not derepress the PHO8 transcript, whereas the pho80 mutant could, irrespective of the amount of Pi in the medium, as has been suggested by genetic study.


1965 ◽  
Vol 6 (1) ◽  
pp. 13-26 ◽  
Author(s):  
G. Dorn

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.


1985 ◽  
Vol 5 (1) ◽  
pp. 248-252 ◽  
Author(s):  
Y Kaneko ◽  
Y Tamai ◽  
A Toh-e ◽  
Y Oshima

A DNA fragment bearing the PHO8 gene, which encodes repressible alkaline phosphatase of Saccharomyces cerevisiae, was cloned. Northern hybridizations with the PHO8 DNA as probe indicated that the PHO8 transcript is 1.8 kilobases in length and is more abundant in cells grown in low-phosphate medium than in high-phosphate medium. The pho9 mutant, whose phenotype is defective in the activity of repressible alkaline phosphatase, produced as much of the PHO8 transcript as did the PHO9+ cells. Hence, the PHO9 product should act at the post-transcriptional level. The pho4 mutant could not derepress the PHO8 transcript, whereas the pho80 mutant could, irrespective of the amount of Pi in the medium, as has been suggested by genetic study.


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