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.

scholarly journals Synergy of fatty acid and reactive alkenal activation of proton conductance through uncoupling protein 1 in mitochondria

2006 ◽  
Vol 395 (3) ◽  
pp. 619-628 ◽  
Author(s):  
Telma C. Esteves ◽  
Nadeene Parker ◽  
Martin D. Brand
Keyword(s):  
Proton Transport ◽  
Uncoupling Protein ◽  
Significant Activity ◽  
Proton Conductance ◽  
Uncoupling Protein 1 ◽  
Physiological Models ◽  
Synergistic Activation ◽  
Brown Adipose ◽  
The Individual ◽  
Kinetics Of

The kinetics of proton transport through mammalian UCP1 (uncoupling protein 1) expressed in yeast mitochondria were measured. There was little or no UCP1 activity in the absence of added palmitate, but significant activity in its presence. The activator 4-HNE (4-hydroxy-2-nonenal) had little effect when added alone, but significantly enhanced proton conductance in the presence of added palmitate. Activation of the proton conductance of UCP1 was synergistic: proton conductance in the presence of both palmitate and 4-HNE was significantly greater than the sum of the individual effects. Mitochondria from control yeast transformed with empty vector showed no such synergy, showing that synergy is a property of UCP1. Activation by the 4-HNE analogue trans-cinnamate showed essentially the same characteristics as activation by 4-HNE. Mitochondria from brown adipose tissue also showed synergistic activation of GDP-sensitive proton conductance by palmitate and 4-HNE. These results show that reactive alkenals activate the proton conductance of UCP1 more strongly when fatty acids are also added, with implications for both mechanistic and physiological models of UCP1 activation.

A mitochondrial uncoupling artifact can be caused by expression of uncoupling protein 1 in yeast

2001 ◽  
Vol 356 (3) ◽  
pp. 779-789 ◽  
Author(s):  
Jeff A. STUART ◽  
James A. HARPER ◽  
Kevin M. BRINDLE ◽  
Mika B. JEKABSONS ◽  
Martin D. BRAND
Keyword(s):  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Physiological Property ◽  
Growth Defect ◽  
Yeast Mitochondria ◽  
Proton Conductance ◽  
Uncoupling Protein 1 ◽  
Mitochondrial Uncoupling ◽  
Mitochondrial Carrier ◽  
Brown Adipose

Uncoupling protein 1 (UCP1) from mouse was expressed in yeast and the specific (GDP-inhibitable) and artifactual (GDP-insensitive) effects on mitochondrial uncoupling were assessed. UCP1 provides a GDP-inhibitable model system to help interpret the uncoupling effects of high expression in yeast of other members of the mitochondrial carrier protein family, such as the UCP1homologues UCP2 and UCP3. Yeast expressing UCP1 at modest levels (approx. 1μg/mg of mitochondrial protein) showed no growth defect, normal rates of chemically uncoupled respiration and an increased non-phosphorylating proton conductance that was completely GDP-sensitive. The catalytic-centre activity of UCP1 in these yeast mitochondria was similar to that in mammalian brown-adipose-tissue mitochondria. However, yeast expressing UCP1 at higher levels (approx. 11μg/mg of mitochondrial protein) showed a growth defect. Their mitochondria had depressed chemically uncoupled respiration rates and an increased proton conductance that was partly GDP-insensitive. Thus, although UCP1 shows native behaviour at modest levels of expression in yeast, higher levels (or rates) of expression can lead to an uncoupling that is not a physiological property of the native protein and is therefore artifactual. This observation might be important in the interpretation of results from experiments in which the functions of UCP1homologues are verified by their ability to uncouple yeast mitochondria.

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.

Dissociation of obesity and insulin resistance in transgenic mice with skeletal muscle expression of uncoupling protein 1

2008 ◽  
Vol 32 (3) ◽  
pp. 352-359 ◽  
Author(s):  
Yvonne Katterle ◽  
Susanne Keipert ◽  
Jana Hof ◽  
Susanne Klaus
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Uncoupling Protein ◽  
Wild Type ◽  
Uncoupling Protein 1 ◽  
Mitochondrial Uncoupling ◽  
High Fat Diets ◽  
Fat Diets ◽  
White Fat

We evaluated the effect of skeletal muscle mitochondrial uncoupling on energy and glucose metabolism under different diets. For 3 mo, transgenic HSA-mUCP1 mice with ectopic expression of uncoupling protein 1 in skeletal muscle and wild-type littermates were fed semisynthetic diets with varying macronutrient ratios (energy % carbohydrate-protein-fat): HCLF (41:42:17), HCHF (41:16:43); LCHF (11:45:44). Body composition, energy metabolism, and insulin resistance were assessed by NMR, indirect calorimetry, and insulin tolerance test, respectively. Gene expression in different organs was determined by real-time PCR. In wild type, both high-fat diets led to an increase in body weight and fat. HSA-mUCP1 mice considerably increased body fat on HCHF but stayed lean on the other diets. Irrespective of differences in body fat content, HSA-mUCP1 mice showed higher insulin sensitivity and decreased plasma insulin and liver triglycerides. Respiratory quotient and gene expression indicated overall increased carbohydrate oxidation of HSA-mUCP1 but a preferential channeling of fatty acids into muscle rather than liver with high-fat diets. Evidence for increased lipogenesis in white fat of HSA-mUCP1 mice suggests increased energy dissipating substrate cycling. Retinol binding protein 4 expression in white fat was increased in HSA-mUCP1 mice despite increased insulin sensitivity, excluding a causal role in the development of insulin resistance. We conclude that skeletal muscle mitochondrial uncoupling does not protect from the development of obesity in all circumstances. Rather it can lead to a “healthy” obese phenotype by preserving insulin sensitivity and a high metabolic flexibility, thus protecting from the development of obesity associated disturbances of glucose homeostasis.

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.

Fish Oil Protects Wild Type and Uncoupling Protein 1‐Deficient Mice from Obesity and Glucose Intolerance by Increasing Energy Expenditure

2019 ◽  
Vol 63 (7) ◽  
pp. 1800813 ◽  
Author(s):  
Tiago E. Oliveira ◽  
Érique Castro ◽  
Thiago Belchior ◽  
Maynara L. Andrade ◽  
Adriano B. Chaves‐Filho ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Fish Oil ◽  
Glucose Intolerance ◽  
Uncoupling Protein ◽  
Wild Type ◽  
Uncoupling Protein 1 ◽  
Deficient Mice

scholarly journals Structural models of mitochondrial uncoupling proteins obtained in DPC micelles are not physiologically relevant for their uncoupling activity

2020 ◽  
Author(s):  
Mathilde S. Piel ◽  
Sandrine Masscheleyn ◽  
Frédéric Bouillaud ◽  
Karine Moncoq ◽  
Bruno Miroux
Keyword(s):  
Uncoupling Protein ◽  
Brown Adipocyte ◽  
Acid Oxidation ◽  
Long Chain Fatty Acids ◽  
Proton Conductance ◽  
Uncoupling Protein 1 ◽  
Inner Mitochondrial Membrane ◽  
Mitochondrial Uncoupling ◽  
Mitochondrial Uncoupling Proteins

AbstractUncoupling protein 1 (UCP1) is found in the inner mitochondrial membrane of brown adipocyte. In the presence of long-chain fatty acids (LCFA), UCP1 increases the proton conductance, which, in turn, increases fatty acid oxidation and energy release as heat. Several atomic models of UCP1 and UCP2 have been obtained by NMR in dodecylphosphocholine (DPC), a detergent known to inactivate UCP1. Based on NMR titration experiment on UCP1 with LCFA, it has been proposed that K56 and K269 are crucial for LCFA binding and UCP1 activation. Given the numerous controversies on the use of DPC for structure-function analyses of membrane proteins, we revisited those UCP1 mutants in a more physiological context by expressing them in the mitochondria of S. cerevisiae. Mitochondrial respiration, assayed on permeabilized spheroplasts, enables the determination of UCP1 activation and inhibition. The K56S, K269S and K56S/K269S mutants did not display any default in activation, which shows that the NMR experiments in DPC detergent are not relevant to understand UCP1 function.

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

scholarly journals Novel reptilian uncoupling proteins: molecular evolution and gene expression during cold acclimation

2008 ◽  
Vol 275 (1637) ◽  
pp. 979-985 ◽  
Author(s):  
Tonia S Schwartz ◽  
Shauna Murray ◽  
Frank Seebacher
Keyword(s):  
Cold Acclimation ◽  
Mitochondrial Membrane ◽  
Uncoupling Protein ◽  
Uncoupling Proteins ◽  
Oxygen Species ◽  
Proton Conductance ◽  
Similar Function ◽  
Uncoupling Protein 1 ◽  
Truncated Protein ◽  
Crocodylus Porosus

Many animals upregulate metabolism in response to cold. Uncoupling proteins (UCPs) increase proton conductance across the mitochondrial membrane and can thereby alleviate damage from reactive oxygen species that may form as a result of metabolic upregulation. Our aim in this study was to determine whether reptiles ( Crocodylus porosus ) possess UCP genes. If so, we aimed to place reptilian UCP genes within a phylogenetic context and to determine whether the expression of UCP genes is increased during cold acclimation. We provide the first evidence that UCP2 and UCP3 genes are present in reptiles. Unlike in other vertebrates, UCP2 and UPC3 are expressed in liver and skeletal muscle of the crocodile, and both are upregulated in liver during cold acclimation but not in muscle. We identified two transcripts of UCP3, one of which produces a truncated protein similar to the UCP3S transcript in humans, and the resulting protein lacks the predicted nucleotide-binding regulatory domain. Our molecular phylogeny suggests that uncoupling protein 1 (UCP1) is ancestral and has been lost in archosaurs. In birds, UCP3 may have assumed a similar function as UCP1 in mammals, which has important ramifications for understanding endothermic heat production.

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