1
|
Yamashoji S, Al Mamun A, Bari L. Cytotoxic effects of menadione on normal and cytochrome c-deficient yeast cells cultivated aerobically or anaerobically. Biochem Biophys Rep 2020; 24:100823. [PMID: 33083578 PMCID: PMC7554363 DOI: 10.1016/j.bbrep.2020.100823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/23/2020] [Accepted: 09/23/2020] [Indexed: 11/16/2022] Open
Abstract
Cytotoxic effects of menadione on normal and cytochrome c-deficient yeast cells were examined on the basis of the cell growth rate, NAD(P)H concentration, reactive oxygen production, plasma membrane H+-ATPase activity, and ethanol production. In aerobically or anaerobically cultured yeast cells, NAD(P)H concentration decreased with increasing concentration of menadione, and the recovery of NAD(P)H concentration was proportional to the cell growth rate. However, there was no relationship among the inhibition of the cell growth and reactive oxygen production, plasma membrane H+-ATPase activity, and ethanol production. Among them, ethanol production showed resistance to the cytotoxicity of menadione, suggesting the resistance of glycolysis to menadione. The growth inhibitory effect of menadione depended on the rapid decrease and the recovery of NAD(P)H rather than production of reactive oxygen species regardless of aerobic culture or anaerobic culture and presence or absence of mitochondrial function. The recovery of NAD(P)H concentration after the addition of menadione might depend on menadione-resistant glycolytic enzymes. The rapid decrease in NAD(P)H concentration in yeast cells was observed after the addition of menadione. The recovery of NAD(P)H concentration after addition of menadione was proportional to the cell growth rate. The above phenomena were observed in suspension of aerobically or anaerobically cultured yeast cells. The above phenomena were observed in suspension of normal or cytochrome c-deficient yeast cells.
Collapse
Affiliation(s)
- Shiro Yamashoji
- Microbial Technology Laboratory, 9-50-514 Kaigandori, Tarumi-ku, Kobe City, Hyogo, 655-0036, Japan
| | - Arafat Al Mamun
- Center for Advanced Research in Sciences, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Latiful Bari
- Center for Advanced Research in Sciences, University of Dhaka, Dhaka, 1000, Bangladesh
| |
Collapse
|
2
|
Dillemans M, Goossens E, Goffin O, Masschelein CA. The Amplification Effect of theILV5Gene on the Production of Vicinal Diketones inSaccharomyces Cerevisiae. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-45-0081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- M. Dillemans
- Institut des Industries de Fermentation, C.E.R.I.A., 1070 Brussels, Belgium
| | - E. Goossens
- Institut des Industries de Fermentation, C.E.R.I.A., 1070 Brussels, Belgium
| | - O. Goffin
- Institut des Industries de Fermentation, C.E.R.I.A., 1070 Brussels, Belgium
| | - C. A. Masschelein
- Institut des Industries de Fermentation, C.E.R.I.A., 1070 Brussels, Belgium
| |
Collapse
|
3
|
MacWilliam IC. THE STRUCTURE, SYNTHESIS AND FUNCTIONS OF THE YEAST CELL WALL-A REVIEW. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/j.2050-0416.1970.tb03338.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
4
|
Parkkinen E, Oura E, Suomalainen H. THE ESTERASES OF BAKER'S YEAST. I. ACTIVITY AND LOCALIZATION IN THE YEAST CELL. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/j.2050-0416.1978.tb03830.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
5
|
Russell I, Garrison IF, Stewart GG. STUDIES ON THE FORMATION OF SPHEROPLASTS FROM STATIONARY PHASE CELLS OFSACCHAROMYCES CEREVISIAE. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/j.2050-0416.1973.tb03499.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
6
|
Schwencke J, González G, Farías G. A RAPID AND REPRODUCIBLE METHOD FOR OBTAINING YEAST PROTOPLASTS. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/j.2050-0416.1969.tb03176.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
7
|
|
8
|
|
9
|
May R, Jacob HE. Vergleich zwischen Atmungsaktivität und morphologischem Zustand isolierter Basidiomyceten-Mitochondrien. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/jobm.19700100406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
10
|
Affiliation(s)
- James A Barnett
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| |
Collapse
|
11
|
Kern K, Nunn CD, Pichová A, Dickinson JR. Isoamyl alcohol-induced morphological change in Saccharomyces cerevisiae involves increases in mitochondria and cell wall chitin content. FEMS Yeast Res 2005; 5:43-9. [PMID: 15381121 DOI: 10.1016/j.femsyr.2004.06.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Revised: 05/03/2004] [Accepted: 06/07/2004] [Indexed: 11/29/2022] Open
Abstract
Isoamyl alcohol reduced growth and induced filament formation in Saccharomyces cerevisiae. Isoamyl alcohol-induced filamentation was accompanied by an almost threefold greater increase in the specific activity of succinate dehydrogenase than in untreated cells, which suggested that isoamyl alcohol treatment caused the cells to produce more mitochondria than in normal yeast form proliferation. This was supported by measuring the dry weight of purified, isolated mitochondria. Filaments have an increased chitin content which is distributed over the majority of their surface, and is not confined to bud scars and the chitin ring between mother and daughter cells as in yeast-form cells.
Collapse
Affiliation(s)
- Kerstin Kern
- Cardiff School of Biosciences, Cardiff University, P.O. Box 915, Cardiff CF10 3TL, UK
| | | | | | | |
Collapse
|
12
|
Barnett JA, Robinow CF. A history of research on yeasts 4: cytology part II, 1950-1990. Yeast 2002; 19:745-72. [PMID: 12112230 DOI: 10.1002/yea.875] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- James A Barnett
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| | | |
Collapse
|
13
|
Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae. Mol Cell Biol 1991. [PMID: 1656231 DOI: 10.1128/mcb.11.11.5487] [Citation(s) in RCA: 94] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Heme is covalently attached to cytochrome c by the enzyme cytochrome c heme lyase. To test whether heme attachment is required for import of cytochrome c into mitochondria in vivo, antibodies to cytochrome c have been used to assay the distributions of apo- and holocytochromes c in the cytoplasm and mitochondria from various strains of the yeast Saccharomyces cerevisiae. Strains lacking heme lyase accumulate apocytochrome c in the cytoplasm. Similar cytoplasmic accumulation is observed for an altered apocytochrome c in which serine residues were substituted for the two cysteine residues that normally serve as sites of heme attachment, even in the presence of normal levels of heme lyase. However, detectable amounts of this altered apocytochrome c are also found inside mitochondria. The level of internalized altered apocytochrome c is decreased in a strain that completely lacks heme lyase and is greatly increased in a strain that overexpresses heme lyase. Antibodies recognizing heme lyase were used to demonstrate that the enzyme is found on the outer surface of the inner mitochondrial membrane and is not enriched at sites of contact between the inner and outer mitochondrial membranes. These results suggest that apocytochrome c is transported across the outer mitochondrial membrane by a freely reversible process, binds to heme lyase in the intermembrane space, and is then trapped inside mitochondria by an irreversible conversion to holocytochrome c accompanied by folding to the native conformation. Altered apocytochrome c lacking the ability to have heme covalently attached accumulates in mitochondria only to the extent that it remains bound to heme lyase.
Collapse
|
14
|
Dumont ME, Cardillo TS, Hayes MK, Sherman F. Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae. Mol Cell Biol 1991; 11:5487-96. [PMID: 1656231 PMCID: PMC361918 DOI: 10.1128/mcb.11.11.5487-5496.1991] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Heme is covalently attached to cytochrome c by the enzyme cytochrome c heme lyase. To test whether heme attachment is required for import of cytochrome c into mitochondria in vivo, antibodies to cytochrome c have been used to assay the distributions of apo- and holocytochromes c in the cytoplasm and mitochondria from various strains of the yeast Saccharomyces cerevisiae. Strains lacking heme lyase accumulate apocytochrome c in the cytoplasm. Similar cytoplasmic accumulation is observed for an altered apocytochrome c in which serine residues were substituted for the two cysteine residues that normally serve as sites of heme attachment, even in the presence of normal levels of heme lyase. However, detectable amounts of this altered apocytochrome c are also found inside mitochondria. The level of internalized altered apocytochrome c is decreased in a strain that completely lacks heme lyase and is greatly increased in a strain that overexpresses heme lyase. Antibodies recognizing heme lyase were used to demonstrate that the enzyme is found on the outer surface of the inner mitochondrial membrane and is not enriched at sites of contact between the inner and outer mitochondrial membranes. These results suggest that apocytochrome c is transported across the outer mitochondrial membrane by a freely reversible process, binds to heme lyase in the intermembrane space, and is then trapped inside mitochondria by an irreversible conversion to holocytochrome c accompanied by folding to the native conformation. Altered apocytochrome c lacking the ability to have heme covalently attached accumulates in mitochondria only to the extent that it remains bound to heme lyase.
Collapse
Affiliation(s)
- M E Dumont
- Department of Biochemistry, University of Rochester School of Medicine and Dentistry, New York 14642
| | | | | | | |
Collapse
|
15
|
In vivo expression and mitochondrial targeting of yeast apoiso-1-cytochrome c fusion proteins. Mol Cell Biol 1990. [PMID: 2172784 DOI: 10.1128/mcb.10.11.5753] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To define the import pathway for apoiso-1-cytochrome c in vivo, the coding region for bacterial chloramphenicol acetyltransferase (CAT) or yeast copper metallothionein (CuMT) was fused to the carboxy terminus of the apoiso-1-cytochrome c (iso-1) coding region. When the resulting iso-1/CAT and iso-1/CuMT fusion proteins were individually expressed in Saccharomyces cerevisiae, they were specifically targeted to the mitochondria and protected from trypsin digestion. Although iso-1/CAT was accessible to heme modification, it remained membrane associated because of the folded conformation of the CAT domain. A small deletion disrupting CAT structure resulted in the translocation of the resulting fusion protein, iso-1/CAT delta, to the intermembrane space, where it functioned efficiently in respiratory electron transfer. Similarly, iso-1/CuMT was heme modified and nearly identical to iso-1 in its ability to support respiratory growth, indicating that the CuMT domain was compatible with translocation to the IMS. Inclusion of copper in the growth medium, which converts the loosely structured apo-CuMT to a tightly folded holo-CuMT, inhibited both heme attachment and respiratory growth without affecting mitochondrial targeting. Thus, by altering the folded conformation of the reporter moiety of these fusion proteins, it was possible to differentiate between those molecules arrested at the mitochondrial targeting step of the cytochrome c import pathway and those translocated to the intermembrane space. By replacing the heme-binding cysteine residues with serines, this system was used to demonstrate that the import requirement for heme attachment operated at the level of membrane translocation and not on mitochondrial targeting in vivo.
Collapse
|
16
|
Nye SH, Scarpulla RC. In vivo expression and mitochondrial targeting of yeast apoiso-1-cytochrome c fusion proteins. Mol Cell Biol 1990; 10:5753-62. [PMID: 2172784 PMCID: PMC361350 DOI: 10.1128/mcb.10.11.5753-5762.1990] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
To define the import pathway for apoiso-1-cytochrome c in vivo, the coding region for bacterial chloramphenicol acetyltransferase (CAT) or yeast copper metallothionein (CuMT) was fused to the carboxy terminus of the apoiso-1-cytochrome c (iso-1) coding region. When the resulting iso-1/CAT and iso-1/CuMT fusion proteins were individually expressed in Saccharomyces cerevisiae, they were specifically targeted to the mitochondria and protected from trypsin digestion. Although iso-1/CAT was accessible to heme modification, it remained membrane associated because of the folded conformation of the CAT domain. A small deletion disrupting CAT structure resulted in the translocation of the resulting fusion protein, iso-1/CAT delta, to the intermembrane space, where it functioned efficiently in respiratory electron transfer. Similarly, iso-1/CuMT was heme modified and nearly identical to iso-1 in its ability to support respiratory growth, indicating that the CuMT domain was compatible with translocation to the IMS. Inclusion of copper in the growth medium, which converts the loosely structured apo-CuMT to a tightly folded holo-CuMT, inhibited both heme attachment and respiratory growth without affecting mitochondrial targeting. Thus, by altering the folded conformation of the reporter moiety of these fusion proteins, it was possible to differentiate between those molecules arrested at the mitochondrial targeting step of the cytochrome c import pathway and those translocated to the intermembrane space. By replacing the heme-binding cysteine residues with serines, this system was used to demonstrate that the import requirement for heme attachment operated at the level of membrane translocation and not on mitochondrial targeting in vivo.
Collapse
Affiliation(s)
- S H Nye
- Department of Cell, Molecular, and Structural Biology, Northwestern University Medical School, Chicago, Illinois 60611
| | | |
Collapse
|
17
|
Coria R, Zalce ME, Mendoza V, Alvarez G, de Cobos AT, Brunner A. Restriction site variation, length polymorphism and changes in gene order in the mitochondrial DNA of the yeast Kluyveromyces lactics. Antonie Van Leeuwenhoek 1990; 58:227-34. [PMID: 1982049 DOI: 10.1007/bf00399333] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The purpose of this work was to compare mitochondrial DNA restriction endonuclease patterns in strains of the yeast Kluyveromyces lactis, from different sources, to see how conserved is the organization of this organellar genome. The mitochondrial DNA of five independently-isolated strains and one of unknown origin were compared. Strains NRRL Y-1205, NRRL Y-8279 and NRRL Y-1140 gave identical patterns. Strain NRRL Y-1564 showed an insertion, with respect to the other three, of approximately 1250 bp. Strain W600B had also an insertion with extra restriction sites for EcoRI, HpaI, HaeIII, HincII and XbaI. On the other hand, strain Y-123 showed a restriction pattern quite different from the others. Sequences putatively encoding apocytochrome b, ATPase subunit 9 and ribosomal RNA large subunit, were localized on the physical maps of three strains. Results demonstrated that the order of these three genes shows a common feature in strains W600B and WM37 (auxotroph of Y-1140) but a different distribution in WM27 (auxotroph derived from Y-123). All these facts explain the extensive intraspecific polymorphism observed in the mtDNA of this yeast.
Collapse
Affiliation(s)
- R Coria
- Depto. de Microbiología, Universidad Nacional Autónoma de México, D.F
| | | | | | | | | | | |
Collapse
|
18
|
Murray WD, Duff SJB, Beveridge TJ. Catabolite Inactivation in the Methylotrophic Yeast
Pichia pastoris. Appl Environ Microbiol 1990; 56:2378-2383. [PMID: 16348251 PMCID: PMC184737 DOI: 10.1128/aem.56.8.2378-2383.1990] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inactivation of the alcohol oxidase enzyme system of
Pichia pastoris
, during the whole-cell bioconversion of ethanol to acetaldehyde, was due to catabolite inactivation. Electron microscopy showed that methanol-grown cells contained peroxisomes but were devoid of these microbodies after the bioconversion. Acetaldehyde in the presence of O
2
was the effector of catabolite inactivation. The process was initiated by the appearance of free acetaldehyde, and was characterized by an increase in the level of cyclic AMP, that coincided with a rapid 55% drop in alcohol oxidase activity. Further enzyme inactivation, believed to be due to proteolytic degradation, then proceeded at a constant but slower rate and was complete 21 h after acetaldehyde appearance. The rate of catabolite inactivation was dependent on acetaldehyde concentration up to 0.14 mM. It was temperature dependent and occurred within 24 h at 37°C and by 6 days at 15°C but not at 3°C. Alcohol oxidase activity was psychrotolerant, with only a 17% decrease in initial specific activity over a temperature drop from 37 to 3°C. In contrast, protease activity was inhibited at temperatures below 15°C. When the bioconversion was run at 3°C, catabolite inactivation was prevented. In the presence of 3 M Tris hydrochloride buffer, 123 g of acetaldehyde per liter was produced at 3°C, compared with 58 g/liter at 30°C. By using 0.5 M Tris in a cyclic-batch procedure, 140.6 g of acetaldehyde was produced.
Collapse
Affiliation(s)
- William D Murray
- Division of Biological Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, and Department of Microbiology, College of Biological Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | | | | |
Collapse
|
19
|
Trinh-Rohlik Q, Maxwell ES. Homologous genes for mouse 4.5S hybRNA are found in all eukaryotes and their low molecular weight RNA transcripts intermolecularly hybridize with eukaryotic 18S ribosomal RNAs. Nucleic Acids Res 1988; 16:6041-56. [PMID: 3399384 PMCID: PMC336846 DOI: 10.1093/nar/16.13.6041] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Previous work has reported the isolation and sequencing of a mouse low molecular weight RNA species designated 4.5S hybridizing RNA or hybRNA because of its ability to intermolecularly hybridize with mouse mRNA and 18S rRNA sequences. Using synthetic DNA oligonucleotide probes we have examined the conservation of this gene sequence and its expression as a lmwRNA transcript across evolution. Southern blot analysis has shown that homologous genes of single or low copy number are found in all eukaryotes examined as well as in E. coli. Northern blot analysis has demonstrated 4.5S hybRNA transcription in all mouse tissues as well as expression in yeast and Xenopus laevis as lmwRNAs of approximately 130 and 100 nucleotides, respectively, as compared with mouse/rat/hamster species of approximately 87 nucleotides. Yeast and X. laevis 4.5S hybRNA homologs, isolated by hybrid-selection, were shown by Northern blot analysis to intermolecularly hybridize with homologous as well as heterologous 18S rRNA sequences. The conservation of 4.5S hybRNA homologous genes and their expression as lmwRNA transcripts with common intermolecular RNA:RNA hybridization capabilities in fungi, amphibians, and mammals argues for a common, conserved and required biological function for this lmwRNA in all eukaryotes and potential utilization of its intermolecular RNA:RNA hybridization capabilities to carry out this function.
Collapse
Affiliation(s)
- Q Trinh-Rohlik
- Department of Biochemistry, North Carolina State University, Raleigh 27695-7622
| | | |
Collapse
|
20
|
Carson DB, Cooney JJ. Spheroplast formation and partial purification of microbodies from hydrocarbon-grown cells ofCladosporium resinae. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf01569552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
21
|
Hosono K, Hahn-Hägerdal B. Separation of yeast protoplasts from membrane ghosts using an aqueous two-phase system. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1986. [DOI: 10.1016/0005-2736(86)90204-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
22
|
Marmiroli N, Lodi T. Modification of nuclear gene expression by inhibition of mitochondrial translation during sporulation in MAT alpha/MATa diploids of Saccharomyces cerevisiae. MOLECULAR & GENERAL GENETICS : MGG 1984; 198:69-74. [PMID: 6394967 DOI: 10.1007/bf00328703] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Sporulation of S. cerevisiae MAT alpha-/MATa was accompanied by a novel pattern of protein synthesis as shown by the disappearance of some "mitotic" polypeptides and by the appearance of a new set of "meiotic" polypeptides. Inhibition of mitochondrial protein synthesis by erythromycin within the 1st h caused the disappearance of several "meiotic" polypeptides. These meiotic polypeptides were also sensitive to cycloheximide and were localized in the cytosol, demonstrating that they were not mitochondrial translational products. Since erythromycin affected neither protein synthesis nor sporulation in a mitochondrially inherited eryr mutant, we conclude that mitochondrial protein synthesis is needed for the expression of some nuclear genes during sporulation.
Collapse
|
23
|
Abstract
The ability of the yeast Saccharomyces cerevisiae to produce ethanol and carbon dioxide from carbohydrates has been exploited by man for thousands of years. During its brief existence protoplast fusion has already become an invaluable tool for investigating the molecular genetics of yeast, as well as an important part of the arsenal of genetic manipulations available to develop new strains. In the case of industrial strains, a mating reaction is usually lacking. Protoplast fusion overcomes this barrier and allows for the genetic analysis of commercially valuable traits. A major block toward broader applicability of fusion is that hybrids becomes more unstable as the genetic backgrounds of the parents diverge. As greater progress in overcoming this problem is made, fusion, by itself and in conjunction with classical hybridization, will become increasingly important in the development of new strains. The incorporation of cytoplasmic elements into yeast protoplasts has the potential to vastly expand the array of biochemical reactions performed by yeasts, thereby increasing the importance of this microbe to mankind.
Collapse
Affiliation(s)
- S Scheinbach
- College of New Rochelle, School of New Resources, New York, NY 10001, USA
| |
Collapse
|
24
|
Ferrero I, Rossi C, Marmiroli N, Donnini C, Puglisi PP. Effect of chloramphenicol, antimycin A and hydroxamate on the morphogenetic development of the dimorphic ascomycete Endomycopsis capsularis. Antonie Van Leeuwenhoek 1981; 47:311-23. [PMID: 7200756 DOI: 10.1007/bf02350782] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Mitochondrial protein synthesis, primary (antimycin-sensitive) respiration and secondary (antimycin-insensitive, salicyl-hydroxamate-sensitive) respiration, have been characterized in the dimorphic yeast Endomycopsis capsularis. The inhibition by chloramphenicol (CAP) of the morphogenetic development from the yeast-like form to the mycelial structure in this yeast could represent the intervention in the morphogenetic process of mitochondrial protein synthesis, since chloramphenicol blocks in vivo and in vitro mitochondrial protein synthesis. In fact, other functions such as primary and secondary respiration, do not seem to play a role in the morphogenetic development since their inhibition by antimycin A (AA) or by salicyl-hydroxamic acid (SHAM) does not affect the process. In addition, mitochondrial protein synthesis has been shown to be uninhibited by the two respiratory inhibitors.
Collapse
|
25
|
Basile G, Di Bello C, Taniuchi H. Formation of an iso-1-cytochrome c-like species containing a covalently bonded heme group from the apoprotein by a yeast cell-free system in the presence of hemin. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(20)79683-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
26
|
|
27
|
Leaper S, Resnick MA, Holliday R. Repair of double-strand breaks and lethal damage in DNA of Ustilago maydis. Genet Res (Camb) 1980; 35:291-307. [PMID: 7439684 DOI: 10.1017/s0016672300014154] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
SUMMARYThe size of nuclear DNA from wild-typeUstilago maydiswas determined to be approximately 6·09 ± 0·3 × 108daltons from neutral sucrose gradient sedimentation analysis. Following exposure to ionizing radiation the nuclear DNA size was reduced due to the production of double-strand breaks in the DNA. These breaks were repaired when the irradiated cells were incubated in medium for at least one hour after irradiation. The repair was seen as a shift in the DNA profile from a low molecular weight region where the control DNA sedimented. Inhibition of protein synthesis by cycloheximide prevented this type of repair. Blocking protein synthesis also decreased the survival of irradiated wild-type cells but not radiation-sensitive mutants. Protein synthesis was necessary within the first one and a half hours after irradiation for the survival of wild-type cells to be unaffected. The results provide additional evidence for an inducible repair process inU. maydis.
Collapse
|
28
|
Pringle AT, Forsdyke J, Rose AH. Scanning electron microscope study of Saccharomyces cerevisiae spheroplast formation. J Bacteriol 1979; 140:289-93. [PMID: 387725 PMCID: PMC216808 DOI: 10.1128/jb.140.1.289-293.1979] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A suspension of Saccharomyces cerevisiae NCY366 in buffered 1.2 M sorbitol containing Zymolyase-5000 (a beta-glucanase-containing preparation/showed maximum osmotic sensitivity after 30 min of incubation at 30 degrees C. A scanning electron microscope study of spheroplast formation, using a very high resolution (4-nm) machine, revealed several new morphological features. The surface of the plug in bud scars on intact cells appeared warty. The wall, which assumed a beady appearance as digestion proceded, ultimately sloughed off to reveal the furrowed surface of the plasma membrane. Bud scars were resistant to digestion and. as incubation proceeded, they became surrounded by an outer annulus, which may be the seconary septum. Wall material was completely removed from the majority of cells only after 60 min of digestion. The surface of spheroplasts was studded with particles, about 25 to 30 nm in diameter. Many spheroplasts had a single large indentation, which may be in that part of the plasma membrane originally underlying the birth scar.
Collapse
|
29
|
von Hedenström M, Höfer M. The effect of nystatin on active transport in Rhodotorula glutinis (gracilis) is restricted to the plasma membrane. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 555:169-74. [PMID: 573138 DOI: 10.1016/0005-2736(79)90080-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The effect of the polyene antibiotic nystatin on the energy-requiring transport of substrates in the obligatory aerobic yeast Rhodotorula glutinis (gracilis) is restricted to its interaction with the plasma membrane, whereas the energy metabolism in mitochondria remains unaffected by the antibiotic. A method for preparation of the mitochondrial fraction from this yeast is described.
Collapse
|
30
|
Campbell WH, Bernofsky C. Mitochondrial glucose-6-phosphate dehydrogenase from Saccharomyces cerevisiae. Mol Cell Biochem 1979; 25:33-42. [PMID: 381893 DOI: 10.1007/bf00211139] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In Saccharomyces cerevisiae, a small proportion of the glucose-6-P dehydrogenase activity is firmly associated with the mitochondrial fraction and is not removed by repeated washing or density-gradient centrifugation. However, the enzyme is released by sonic disruption. Mitochondrial glucose-6-P dehydrogenase that is released by sonication and partially purified has been found to be similar to cytosol glucose-6-P dehydrogenase with respect to electrophoretic mobility, isoelectric point, pH optimum, molecular size, and apparent KM's for NADP+ and glucose-6-P. These results indicate that a single species of glucose-6-P dehydrogenase is synthesized in S. cerevisiae and that the enzyme has more than one intracellular location. Mitochondrial glucose-6-P dehydrogenase may be a source of intramitochondrial NADPH and may function with hexokinase and transhydrogenase to provide a pathway for glucose oxidation that is coupled to the synthesis of mitochondrial ATP. A constant proportion of total glucose-6-P dehydrogenase activity remains compartmented in the mitochondrial fraction throughout the growth cycle.
Collapse
|
31
|
Willsky GR. Characterization of the plasma membrane Mg2+-ATPase from the yeast, Saccharomyces cerevisiae. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)50762-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
32
|
Abstract
Cells of the osmotolerant yeast Saccharomyces rouxii were transformed to protoplasts in good yield (85%) by digesting cell walls with snail-gut enzyme in the presence of 10 mM dithioerythritol, 0.1 M sodium phosphate buffer (pH 6.8), and 2.0 M KCl. The requirement for 2.0 M KCl compares with that for S. bisporus var. mellis (another osmotolerant species) and contrasts with the 0.3 to 0.8 M KCl concentrations used in the preparation of most yeast protoplasts. Short digestions (60 min or less) produced mostly spheroplasts; longer incubations (90 min or more) yielded mostly protoplasts as judged by electron micrographs. These protoplasts could be transferred to 1.0 M KCl or 2.0 M sorbitol without lysing, but lysis was pronounced in 0.5 M KCl or 1.0 M mannitol and complete in 0.02 M KCl. Protoplasts were separated from isolated cell wall remnants and debris by centrifugation on a linear gradient of Ficoll 400 (35 to 17.5%, wt/vol) containing 2.0 M KCl. Both crude and fractionated protoplast preparations contained vesicles which were identified with the periplasmic bodies of whole cells. Some of the periplasmic bodies were connected to protoplasts by fine pedicels; others appeared free. Independent degeneracy of periplasmic bodies was occasionally observed. beta-Fructofuranosidase (EC 3.2.1.26) activity is cryptic (physically) in cells of S. rouxii in contrast to the expressed enzyme (periplasmic space) of other Saccharomyces species. This enzyme remains cryptic in protoplast preparations of S. rouxii but is expressed upon lysis. The same specific activities were found per unit cell or protoplast. The possible association of the cryptic enzyme with periplasmic bodies is discussed.
Collapse
|
33
|
Guérin B, Labbe P, Somlo M. Preparation of yeast mitochondria (Saccharomyces cerevisiae) with good P/O and respiratory control ratios. Methods Enzymol 1979; 55:149-59. [PMID: 379498 DOI: 10.1016/0076-6879(79)55021-6] [Citation(s) in RCA: 176] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
34
|
Tsujita Y, Endo A. Presence and partial characterization of internal acid protease of Aspergillus oryzae. Appl Environ Microbiol 1978; 36:237-42. [PMID: 29561 PMCID: PMC291207 DOI: 10.1128/aem.36.2.237-242.1978] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The presence and partial characterization of the internal acid protease (EC 2.4.23.6) of Aspergillus oryzae has been investigated. Although the majority of the acid protease is external and present in the culture filtrate, a significant amount of the active enzyme is firmly bound to the cells; it is not released by repeated extraction of cells with 0.9% sodium chloride but is liberated into the soluble fraction during disruption of cells. The internal acid protease, as well as the external one, was separated into two major molecular forms (F1 and F2) with molecular weights of 60,000 and 42,000, respectively, by chromatography on Sephadex G-100 and on CM-Sephadex C-50. The partially purified internal enzymes had the same catalytic and immunological properties, as did the external enzyme.
Collapse
|
35
|
Morita T, Yielding KL. Photolytic binding of the monoazido analog of ethidium to yeast mitochondrial DNA: competition by ethidium. Mutat Res 1978; 54:27-32. [PMID: 353546 DOI: 10.1016/0165-1161(78)90131-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The [14C]-labeled monoazido analog of ethidium, 3-amino-8-azido-5-ethyl-6-phenylphenanthridinium chloride, when mixed with yeast cells and photolyzed, produced covalent adducts with both nuclear and mitochondrial DNA via the light-generated nitrene. The binding efficiency was about 12 times higher in mitochondrial than nuclear DNA. Moreover, the parent ethidium bromide at a 5-fold excess was an effective competitor for the binding of the monoazide analog with mitochondrial DNA, but not with nuclear DNA.
Collapse
|
36
|
Blanc H, Dujon B, Guerineau M, Slonimski PP. Detection of specific DNA sequences in yeast by colony hybridization. MOLECULAR & GENERAL GENETICS : MGG 1978; 161:311-5. [PMID: 353517 DOI: 10.1007/bf00331006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A procedure is described for the detection of specific DNA sequences in Saccharomyces cerevisiae. This method allows a rapid screening of a large number of yeast colonies. The yeast cells of each colony, grown on nitrocellulose filters, are converted, in situ, to protoplasts by snail enzyme, and are then lysed and their DNAs are denatured and fixed on the filter. The presence of the specific DNA sequence is detected directly on the filter by hybridization with a radioactive cRNA. We have used successfully this technique to detect the presence or the absence of specific mt DNA sequences in p+, p- and p0 strains, and to detect the presence or the absence of the 2 mum DNA sequences in different strains.
Collapse
|
37
|
Jauniaux JC, Urrestarazu LA, Wiame JM. Arginine metabolism in Saccharomyces cerevisiae: subcellular localization of the enzymes. J Bacteriol 1978; 133:1096-1107. [PMID: 205532 PMCID: PMC222139 DOI: 10.1128/jb.133.3.1096-1107.1978] [Citation(s) in RCA: 140] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Subcellular localization of enzymes of arginine metabolism in Saccharomyces cerevisiae was studied by partial fractionation and stepwise homogenization of spheroplast lysates. These enzymes could clearly be divided into two groups. The first group comprised the five enzymes of the acetylated compound cycle, i.e., acetylglutamate synthase, acetylglutamate kinase, acetylglutamyl-phosphate reductase, acetylornithine aminotransferase, and acetylornithine-glutamate acetyltransferase. These enzymes were exclusively particulate. Comparison with citrate synthase and cytochrome oxidase, and results from isopycnic gradient analysis, suggested that these enzymes were associated with the mitochondria. By contrast, enzymatic activities going from ornithine to arginine, i.e., arginine pathway-specific carbamoylphosphate synthetase, ornithine carbamoyltransferase, argininosuccinate synthetase, and argininosuccinate lyase, and the two first catabolic enzymes, arginase and ornithine aminotransferase, were in the "soluble" fraction of the cell.
Collapse
|
38
|
Mainzer SE, Slayman CW. Mitochondrial adenosine triphosphatase of wild-type and poky Neurospora crassa. J Bacteriol 1978; 133:584-92. [PMID: 24038 PMCID: PMC222062 DOI: 10.1128/jb.133.2.584-592.1978] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We have compared the adenosine triphosphatase (ATPase) activity of mitochondria prepared from wild-type Neurospora crassa and from poky, a maternally inherited mutant known to possess defective mitochondrial ribosomes and reduced amounts of cytochromes aa3 and b. poky contains two distinct forms of mitochondrial ATPase. The first is normal in its Km for ATP, specificity for nucleotides and divalent cations, pH optimum, cold stability, and sensitivity to inhibitors (oligomycin, N,N-dicyclohexyl carbodiimide, and adenylyl imidodiphosphate). The fact that membrane-bound, cold-stable, oligomycin-sensitive ATPase activity is present in poky (with an activity of 1.93 +/- 0.03 mumol/min-mg of protein compared with 1.33 +/- 0.07 mumol/min-mg of protein in the wild-type strain) and also in chloramphenicol-grown wild-type cells suggests that products of mitochondrial protein synthesis play only a limited role in the attachment of the mitochondrial ATPase to the membrane in Neurospora. poky also contains a second form of mitochondrial ATPase, which has an activity of 1.5 +/- 0.2 mumol/min-mg of protein, is oligomycin sensitive but cold labile, and presumably is attached less firmly to the mitochondrial membrane. The two forms, added together, represent a substantial overproduction of mitochondrial ATPase by poky.
Collapse
|
39
|
Djavadi FH, Moradi M, Etemad-Pour F, Djavadi-Ohaniance L. [Inhibition of the yeast respiratory system by Zn-protoporphyrin and effect of photolysis of this substance]. Biochimie 1977; 59:805-11. [PMID: 203338 DOI: 10.1016/s0300-9084(77)80211-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We have shown earlier that yeast cells grown in synthetic mediums supplemented with Zn++ accumulate large amounts of Zn-protoporphyrin within their mitochondria. This accumulation is accompanied by an inhibition of respiration (3). This study deals with the effect of light on the respiratory inhibition and the release of respiratory control which are observed if Zn-protoporphyrin is added to isolated mitochondria which are initially devoid of this pigment. In addition, we have studied the effect of light on the respiratory inhibition exerted by Zn-protoporphyrin accumulated in vivo. The following results were obtained: 1) The light-induced destruction of Zn-protoporphrin which had been added in vitro to Zn-protoporphyrin-free mitochondria significantly inhibits respiration and phosphorylation. Under these conditions, the extent of the inhibitions increases with the concentration of the added Zn-protoporphyrin and the duration of illumination. 2) Accumulation of Zn-protoporphyrin within the cells causes an inhibition of the respiratory activities and the activities of succinate-cytochrome c reductase and NADH-cytochrome c reductase of the mitochondria. Illumination of the isolated mitochondria from Zn-protoporphyrin-containing cells enhances the inhibition of these activities. No light-induced inhibition of these activities is observed with mitochondria from cells devoid of Zn-protoporphyrin.
Collapse
|
40
|
Urrestarazu LA, Vissers S, Wiame JM. Change in location of ornithine carbamoyltransferase and carbamoylphosphate synthetase among yeasts in relation to the arginase/ornithine carbamoyltransferase regulatory complex and the energy status of the cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1977; 79:473-81. [PMID: 200419 DOI: 10.1111/j.1432-1033.1977.tb11830.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
41
|
Gardella RS, Macquillan AM. Ethidium bromide mutagenesis in Saccharomyces cerevisiae: modulation by growth medium components. Mutat Res 1977; 46:269-84. [PMID: 331106 DOI: 10.1016/0165-1161(77)90004-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
42
|
Haarasilta S, Taskinen L. Location of three key enzymes of gluconeogenesis in baker's yeast. Arch Microbiol 1977; 113:159-61. [PMID: 196563 DOI: 10.1007/bf00428597] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The subcellular location of hexose diphosphatase, phosphoenolpyruvate carboxykinase and pyruvate carboxylase in baker's yeast (Saccharomyces cerevisiae) was investigated by density gradient centrifugation of spheroplast lysates obtained by osmotic shock treatment of spheroplasts and centrifugation for 10000 g x min. On the evidence obtained from zonal separations these three enzymes of gluconeogenesis are most probably located in the soluble cytosol.
Collapse
|
43
|
Johnston LH. The use of a novel plate assay in a search for yeast mutants defective in deoxyribonucleases. MOLECULAR & GENERAL GENETICS : MGG 1977; 152:219-22. [PMID: 327278 DOI: 10.1007/bf00268821] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Methods by which the intracellular enzymes deoxyribonuclease, ribonuclease and protease can be assayed in whole colonies of Saccharomyces cerevisiae on agar plates are described. A search for mutants deficient in deoxyribonuclease has been carried out. Two types of mutant are described. One apparently fails to produce deoxyribonuclease, ribonuclease or protease on agar plates and the other apparently fails to produce deoxyribonuclease and ribonuclease.
Collapse
|
44
|
Controlled preparation of protoplasts ofKloeckera sp. 2201 grown on methanol. ACTA ACUST UNITED AC 1977. [DOI: 10.1007/bf01390666] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
45
|
Daily OP, Cuttitta FF, MacQuillan AM. The absence of DNA photoreactivation enzyme in yeast mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 454:375-81. [PMID: 793625 DOI: 10.1016/0005-2787(76)90239-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mitochondria isolated from haploid yeast cells by spheroplast lysis were purified by flotation on renografin gradients. Electron micrographs and respiratory control ratios revealed that the purified mitochondria were still intact and functional. Assays for photoreactivation enzyme using as substrate [3H]-thymine-labeled Escherichia coli DNA were performed on crude and purified mitochondrial preparations. While the crude preparation contained high amounts of photoreactivation enzyme, it appeared to be associated with contaminating nuclei. The purified mitochondria lacked any photoreactivation enzyme activity. We suggest that yeast mitochondria do not normally contain photoreactivation enzyme.
Collapse
|
46
|
Abstract
A method is described for preparing yeast mitochondria rapidly (within one hour) by using the MSK Bronwill Cell homogenizer. Yeast mitochondria obtained by the method exhibit relatively good respiratory controls and ADP/O ratios. The method is convenient for small or large amounts of yeast cells (from 5 to a hundred grams, wet weight) and gave a yield of 3 to 5 mg protein/g wet weight of yeast mitochondria.
Collapse
|
47
|
|
48
|
Schousboe I. Triacylglycerol lipase activity in baker's yeast (Saccharomyces cerevisiae). BIOCHIMICA ET BIOPHYSICA ACTA 1976; 424:366-75. [PMID: 816373 DOI: 10.1016/0005-2760(76)90026-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
An investigation of intracellular triacylglycerol lipase activity in baker's yeast (Saccharomyces cerevisiae) has been performed using emulsified triolein as substrate. Bovine serum has been used as emulsifier since it was found superior to gum arabic and albumin with respect to reproducibility of both triacylglycerol concentration in the assay mixture and specific lipase activity. No extracellular activity could be detected neither with whole cells nor with water or detergent "extracts" of intact cells as enzyme source. With disrupted cells the level of triacylglycerol lipase activity at a triacylglycerol concentration of 9.6 mM, at pH 7.5, and 30 degrees C was 190 mumol free fatty acids per h per g disrupted cells. Fractionation of a cytoplasmic extract of disrupted cells revealed that about 70% of the activity was associated with membrane fractions and 60% of this activity was present in the mitochondrial fraction. Purification of this fraction was followed by an increase in specific lipase activity which parallels the increase in specific activity of the cytochrome c oxidase.
Collapse
|
49
|
Hanssens L, Verachtert H. Adenosine 5'-monophosphate-stimulated cyanide-insensitive respiration in mitochondria of Moniliella tomentosa. J Bacteriol 1976; 125:829-36. [PMID: 3496 PMCID: PMC236155 DOI: 10.1128/jb.125.3.829-836.1976] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondria of the yeastlike fungus Moniliella tomentosa oxidize reduced nicotinamide adenine dinucleotide, reduced nicotinamide adenine dinucleotide phosphate, succinate, isocitrate, and lactate. These oxidations are completely inhibited by cyanide or antimycin A in mitochondria isolated from cells grown in the standard medium. On the other hand, the oxidation of all substrates, except lactate, is almost completely insensitive to cyanide or antimycin A in mitochondria from cells grown in the presence of ethidium bromide. In this instance, the oxidation is mainly mediated by an alternate oxidase which can be blocked by salicyl hydroxamic acid. The alternate oxidase can be specifically stimulated by adenosine 5'-monophosphate and this provides a new method for the characterization of the alternate oxidase in mitochondria of M. tomentosa.
Collapse
|
50
|
Hixon SC, Yielding KL. A protective effect of caffeine on the ethidium induced petite mutation in yeast. Mutat Res 1976; 34:195-200. [PMID: 765809 DOI: 10.1016/0027-5107(76)90124-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A prerequisite for petite induction by ethidium bromide (EB) is an initial covalent attachment of the drug to cytoplasmic DNA. This DNA modification is thought to initiate repair processes. The repair inhibitor, caffeine, provided a protective effect against the ethidium induced petite mutation at caffeine concentrations known to inhibit the repair of UV damage in cytoplasmic DNA (Fig. 1). Mitochondrial DNA isolated from yeast exposed to EB in vivo was not as degraded in the presence of both drugs as with EB alone (Fig. 2).
Collapse
|