scholarly journals CARDIOLIPIN CONTENT OF WILD TYPE AND MUTANT YEASTS IN RELATION TO MITOCHONDRIAL FUNCTION AND DEVELOPMENT

1971 ◽  
Vol 48 (3) ◽  
pp. 490-502 ◽  
Author(s):  
S. Jakovcic ◽  
G. S. Getz ◽  
M. Rabinowitz ◽  
H. Jakob ◽  
H. Swift
Keyword(s):  
Respiratory Function ◽  
Mitochondrial Membrane ◽  
Phospholipid Composition ◽  
Growth Conditions ◽  
Wild Type ◽  
Mitochondrial Membranes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Similar Growth ◽  
Wild Type Yeast ◽  
Respiratory Deficient

The phospholipid composition of various strains of the yeast, Saccharomyces cerevisiae, and several of their derived mitochondrial mutants grown under conditions designed to induce variations in the complement of mitochondrial membranes has been examined. Wild type and petite (cytoplasmic respiratory deficient) yeasts were fractionated into various subcellular fractions, which were monitored by electron microscopy and analyzed for cytochrome oxidase (in wild type) and phospholipid composition. 90% or more of the phospholipid, cardiolipin was found in the mitochondrial membranes of wild type and petite yeast. Cardiolipin content differed markedly under various growth conditions. Stationary yeast grown in glucose had better developed mitochondria and more cardiolipin than repressed log phase yeast. Aerobic yeast contained more cardiolipin than anaerobic yeast. Respiration-deficient cytoplasmic mitochondrial mutants, both suppressive and neutral, contained less cardiolipin than corresponding wild types. A chromosomal mutant lacking respiratory function had normal cardiolipin content. Log phase cells grown in galactose and lactate, which do not readily repress the development of mitochondrial membranes, contained as much cardiolipin as stationary phase cells grown in glucose. Cytoplasmic mitochondrial mutants respond to changes in the glucose concentration of the growth medium by variations in their cardiolipin content in the same way as wild type yeast does under similar growth conditions. It is concluded that cardiolipin content of yeast is correlated with, and is a good indicator of, the state of development of mitochondrial membrane.

Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Ethylene Production ◽  
Atp Synthesis ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Absolute Requirement ◽  
Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

Escape of mitochondrial DNA to the nucleus in yme1 yeast is mediated by vacuolar-dependent turnover of abnormal mitochondrial compartments

1998 ◽  
Vol 111 (16) ◽  
pp. 2455-2464 ◽  
Author(s):  
C.L. Campbell ◽  
P.E. Thorsness
Keyword(s):  
Alkaline Phosphatase ◽  
Mitochondrial Dna ◽  
High Rate ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mitochondrial Defects ◽  
Proteinase A ◽  
Abnormal Mitochondria ◽  
Wild Type Yeast

Inactivation of Yme1p, a mitochondrially-localized ATP-dependent metallo-protease in the yeast Saccharomyces cerevisiae, causes a high rate of DNA escape from mitochondria to the nucleus as well as pleiotropic functional and morphological mitochondrial defects. The evidence presented here suggests that the abnormal mitochondria of a yme1 strain are degraded by the vacuole. First, electron microscopy of Yme1p-deficient strains revealed mitochondria physically associated with the vacuole via electron dense structures. Second, disruption of vacuolar function affected the frequency of mitochondrial DNA escape from yme1 and wild-type strains. Both PEP4 or PRC1 gene disruptions resulted in a lower frequency of mitochondrial DNA escape. Third, an in vivo assay that monitors vacuole-dependent turnover of the mitochondrial compartment demonstrated an increased rate of mitochondrial turnover in yme1 yeast when compared to the rate found in wild-type yeast. In this assay, vacuolar alkaline phosphatase, encoded by PHO8, was targeted to mitochondria in a strain bearing disruption to the genomic PHO8 locus. Maturation of the mitochondrially localized alkaline phosphatase pro-enzyme requires proteinase A, which is localized in the vacuole. Therefore, alkaline phosphatase activity reflects vacuole-dependent turnover of mitochondria. This assay reveals that mitochondria of a yme1 strain are taken up by the vacuole more frequently than mitochondria of an isogenic wild-type strain when these yeast are cultured in medium necessitating respiratory growth. Degradation of abnormal mitochondria is one pathway by which mitochondrial DNA escapes and migrates to the nucleus.

scholarly journals Molecular Mechanism by Which Cobra Venom Cardiotoxins Interact with the Outer Mitochondrial Membrane

Toxins ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 425
Author(s):  
Feng Li ◽  
Indira H. Shrivastava ◽  
Paul Hanlon ◽  
Ruben K. Dagda ◽  
Edward S. Gasanoff
Keyword(s):  
Molecular Dynamics ◽  
Molecular Mechanism ◽  
Atp Synthase ◽  
Mitochondrial Membrane ◽  
Molecular Mechanisms ◽  
Phospholipid Composition ◽  
Phospholipid Bilayer ◽  
Cobra Venom ◽  
Outer Mitochondrial Membrane ◽  
Mitochondrial Membranes

Cardiotoxin CTII from Naja oxiana cobra venom translocates to the intermembrane space (IMS) of mitochondria to disrupt the structure and function of the inner mitochondrial membrane. At low concentrations, CTII facilitates ATP-synthase activity, presumably via the formation of non-bilayer, immobilized phospholipids that are critical in modulating ATP-synthase activity. In this study, we investigated the effects of another cardiotoxin CTI from Naja oxiana cobra venom on the structure of mitochondrial membranes and on mitochondrial-derived ATP synthesis. By employing robust biophysical methods including 31P-NMR and 1H-NMR spectroscopy, we analyzed the effects of CTI and CTII on phospholipid packing and dynamics in model phosphatidylcholine (PC) membranes enriched with 2.5 and 5.0 mol% of cardiolipin (CL), a phospholipid composition that mimics that in the outer mitochondrial membrane (OMM). These experiments revealed that CTII converted a higher percentage of bilayer phospholipids to a non-bilayer and immobilized state and both cardiotoxins utilized CL and PC molecules to form non-bilayer structures. Furthermore, in order to gain further understanding on how cardiotoxins bind to mitochondrial membranes, we employed molecular dynamics (MD) and molecular docking simulations to investigate the molecular mechanisms by which CTII and CTI interactively bind with an in silico phospholipid membrane that models the composition similar to the OMM. In brief, MD studies suggest that CTII utilized the N-terminal region to embed the phospholipid bilayer more avidly in a horizontal orientation with respect to the lipid bilayer and thereby penetrate at a faster rate compared with CTI. Molecular dynamics along with the Autodock studies identified critical amino acid residues on the molecular surfaces of CTII and CTI that facilitated the long-range and short-range interactions of cardiotoxins with CL and PC. Based on our compiled data and our published findings, we provide a conceptual model that explains a molecular mechanism by which snake venom cardiotoxins, including CTI and CTII, interact with mitochondrial membranes to alter the mitochondrial membrane structure to either upregulate ATP-synthase activity or disrupt mitochondrial function.

scholarly journals Ubiquinone is not required for proton conductance by uncoupling protein 1 in yeast mitochondria

2004 ◽  
Vol 379 (2) ◽  
pp. 309-315 ◽  
Author(s):  
Telma C. ESTEVES ◽  
Karim S. ECHTAY ◽  
Tanya JONASSEN ◽  
Catherine F. CLARKE ◽  
Martin D. BRAND
Keyword(s):  
Proton Transport ◽  
Uncoupling Protein ◽  
Coenzyme Q ◽  
Yeast Mitochondria ◽  
Proton Conductance ◽  
Wild Type ◽  
Uncoupling Protein 1 ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mutant Strains ◽  
Wild Type Yeast

Q (coenzyme Q or ubiquinone) is reported to be a cofactor obligatory for proton transport by UCPs (uncoupling proteins) in liposomes [Echtay, Winkler and Klingenberg (2000) Nature (London) 408, 609–613] and for increasing the binding of the activator retinoic acid to UCP1 [Tomás, Ledesma and Rial (2002) FEBS Lett. 526, 63–65]. In the present study, yeast (Saccharomyces cerevisiae) mutant strains lacking Q and expressing UCP1 were used to determine whether Q was required for UCP function in mitochondria. Wild-type yeast strain and two mutant strains (CENΔCOQ3 and CENΔCOQ2), both not capable of synthesizing Q, were transformed with the mouse UCP1 gene. UCP1 activity was measured as fatty acid-dependent, GDP-sensitive proton conductance in mitochondria isolated from the cells. The activity of UCP1 was similar in both Q-containing and -deficient yeast mitochondria. We conclude that Q is neither an obligatory cofactor nor an activator of proton transport by UCP1 when it is expressed in yeast mitochondria.

Use of sugarcane molasses “B” as an alternative for ethanol production with wild-type yeast Saccharomyces cerevisiae ITV-01 at high sugar concentrations

2011 ◽  
Vol 35 (4) ◽  
pp. 605-614 ◽  
Author(s):  
C. L. Fernández-López ◽  
B. Torrestiana-Sánchez ◽  
M. A. Salgado-Cervantes ◽  
P. G. Mendoza García ◽  
M. G. Aguilar-Uscanga
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Sugarcane Molasses ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
High Sugar ◽  
Wild Type Yeast

Regulation of phospholipid synthesis in yeast by zinc

2005 ◽  
Vol 33 (5) ◽  
pp. 1150-1153 ◽  
Author(s):  
G.M. Carman
Keyword(s):  
Zinc Deficiency ◽  
Phospholipid Composition ◽  
Phospholipid Synthesis ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Sequence Element ◽  
Phosphatidylserine Synthase ◽  
Zinc Depletion ◽  
Upstream Activating Sequence ◽  
And Function

The yeast Saccharomyces cerevisiae has the ability to cope with a variety of stress conditions (e.g. zinc deficiency) by regulating the expression of enzyme activities including those involved with phospholipid synthesis. Zinc is an essential mineral required for the growth and metabolism of S. cerevisiae. Depletion of zinc from the growth medium of wild-type cells results in alterations in phospholipid composition including an increase in PI (phosphatidylinositol) and a decrease in phosphatidylethanolamine. These changes can be attributed to an increase in PIS1-encoded PI synthase activity and a decrease in the activities of several CDP-diacylglycerol pathway enzymes including the CHO1-encoded PS (phosphatidylserine) synthase. The reduction in PS synthase in response to zinc depletion is due to a repression mechanism that involves the UASINO (inositol upstream activating sequence) element in the CHO1 promoter and the negative transcription factor Opi1p. These factors are also responsible for the inositol-mediated repression of CHO1. This regulation may play an important role in allowing cells to adapt to zinc deficiency given the essential roles that phospholipids play in the structure and function of cellular membranes.

scholarly journals Membrane proteins associated with amino acid transport by yeast (Saccharomyces cerevisiae)

1980 ◽  
Vol 192 (2) ◽  
pp. 659-664 ◽  
Author(s):  
J R Woodward ◽  
H L Kornberg
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Membrane Proteins ◽  
Wild Type Strain ◽  
Osmotic Shock ◽  
Wild Type ◽  
Amino Acid Permease ◽  
Yeast Saccharomyces Cerevisiae ◽  
General Amino Acid Permease ◽  
Wild Type Yeast

Cells of the wild-type yeast (Saccharomyces cerevisiae) strain Y185, grown under conditions that de-repress the formation of a general amino acid permease (‘Gap’) system, bind delta-N-chloroacetyl[1-(14)C]ornithine; L- and D-amino acid substrates of the general amino acid permease system protect against this binding. The protein responsible is released from the cells by homogenization or by preparation of protoplasts; it is not released by osmotic shock. This protein is virtually absent from the wild-type strain when it is grown under conditions that repress the general amino acid permease system, and is also absent from a Gap- mutant Y185-His3, selected by its resistance to D-amino acids. This mutant and repressed wild-type cells also fail to form a number of membrane proteins elaborated by de-repressed wild-type cells. It is possible that all these proteins are components of the general amino acid permease system.

scholarly journals Changes in membrane proteins associated with inhibition of the general amino acid permease of yeast (Saccharomyces cerevisiae)

1981 ◽  
Vol 196 (2) ◽  
pp. 531-536 ◽  
Author(s):  
J R Woodward ◽  
H L Kornberg
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Amino Acid ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Wild Type ◽  
Amino Acid Permease ◽  
Yeast Saccharomyces Cerevisiae ◽  
General Amino Acid Permease ◽  
Wild Type Yeast

The general amino acid permease (‘Gap’) system of the wild-type yeast (Saccharomyces cerevisiae) strain Y185 is inhibited by the uptake and accumulation of its substrate amino acids. Surprisingly, this inhibition persists even after ‘pools’ of amino acids, accumulated initially, have returned to normal sizes. Recovery from this inhibition depends on a supply of energy and involves the synthesis of a membrane protein component of the Gap system.

Multiple isoacceptor forms of several transfer ribonucleic acids in a mutant yeast strain

1978 ◽  
Vol 56 (1) ◽  
pp. 51-59 ◽  
Author(s):  
J. B. Bell ◽  
K. Bruce Jacobson ◽  
Lee R. Shugart
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Growth Conditions ◽  
Wild Type ◽  
Reverse Phase ◽  
Ribonucleic Acids ◽  
Multiple Peaks ◽  
Single Form ◽  
In The Wild ◽  
Wild Type Yeast

By use of reverse phase 5 chromatography, a strain of Saccharomyces cerevisiae (XB109-5B) has been shown to exhibit multiple isoaccepting forms for several of the transfer ribonucleic acids (tRNAs). This is in contrast with a standard wild-type strain where only one acceptor is found for each tRNA studied. Multiple peaks for tRNATyr, tRNAPhe, tRNASer, and tRNAVal have been detected for strain XB109-5B. However, the observation of multiple isoacceptors cannot be extended to all tRNAs in this strain since tRNAAsp appears as a single form that is the same as in the wild type. The appearance of multiple peaks was found to depend on the growth conditions of the cells. The tRNA profiles of XB109-5B that was grown rapidly with vigorous aeration differed the most from profiles of comparably grown wild-type yeast, whereas tRNA from this mutant, grown without shaking or supplementary aeration, appeared the same as the wild type. The minor nucleoside composition of the isoacceptors of tRNAPhe was obtained.

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