Mitochondrial protein expression in tomato fruit during on-vine ripening and cold storage

2002 ◽  
Vol 29 (7) ◽  
pp. 827 ◽  
Author(s):  
Ruth C. Holtzapffel ◽  
Patrick M. Finnegan ◽  
A. Harvey Millar ◽  
Murray R. Badger ◽  
David A. Day
Keyword(s):  
Electron Transport ◽  
Alternative Oxidase ◽  
Uncoupling Protein ◽  
Tricarboxylic Acid Cycle ◽  
Tomato Fruit ◽  
Expression Patterns ◽  
Mitochondrial Protein ◽  
Respiratory Control ◽  
Isolated Mitochondria ◽  
Plant Uncoupling Protein

We have investigated the activity and abundance of a number of respiratory chain components in ripening and cold-treated tomato fruits (Lycopersicon esculentum L. Mill cvv. Moneymaker and Sweetie). Expression of the alternative oxidase (AOX) protein increased dramatically in both situations. Levels of the plant uncoupling protein (UCP) initially fell, but increased substantially in the later stages of ripening. In contrast, ATP synthase subunits and the COXII subunit of cytochrome oxidase decreased during ripening and increased slightly in response to cold stress. Other proteins involved in electron transport, tricarboxylic acid cycle function, chaperonin function, and membrane transport were also studied. These showed varying degrees of enhanced and depressed expression patterns. There were modest changes in whole fruit respiratory activities, and electron transport capacity of isolated mitochondria in response to these stimuli. However, respiratory control by ADP in the isolated mitochondria decreased as AOX capacity and abundance increased, indicating that although total respiration rates changed little, flux between the coupled and uncoupled pathways altered. The changes observed in AOX and UCP accumulation in tomato fruit that were vine-ripened were significantly different from post-harvest ripening patterns previously reported. The altered protein profiles are discussed in the context of on- and off-vine ripening and the potentially different roles of uncoupled respiration in each situation.

scholarly journals Pyruvate metabolism in castor-bean mitochondria

1986 ◽  
Vol 239 (2) ◽  
pp. 355-361 ◽  
Author(s):  
M A Brailsford ◽  
A G Thompson ◽  
N Kaderbhai ◽  
R B Beechey
Keyword(s):  
Electron Transport ◽  
Castor Bean ◽  
Silicone Oil ◽  
Ricinus Communis ◽  
Mitochondrial Protein ◽  
Respiratory Control ◽  
O2 Uptake ◽  
Salicylhydroxamic Acid ◽  
Oxidation Rates ◽  
Pyruvate Oxidation

We report the isolation of mitochondria from the endosperm of castor beans (Ricinus communis). These mitochondria oxidized succinate, external NADH, malate and pyruvate with respiratory-control and ADP/O ratios consistent with those found previously with mitochondria from other plant sources. The mitochondria exhibited considerable sensitivity to the electron-transport-chain inhibitors antimycin A and cyanide when oxidizing succinate and external NADH. Pyruvate-dependent O2 uptake was relatively insensitive to these inhibitors, although the residual O2 uptake could be inhibited by salicylhydroxamic acid. We conclude that a cyanide-insensitive alternative terminal oxidase is functional in these mitochondria. However, electrons from the succinate dehydrogenase or external NADH dehydrogenase seem to have no access to this pathway. There is little interconnection between the salicylhydroxamic acid-sensitive and cyanide-sensitive pathways of electron transport. alpha-Cyanocinnamate and its analogues, compound UK5099 [alpha-cyano-beta-(1-phenylindol-3-yl)acrylate] and alpha-cyano-4-hydroxycinnamate, were all found to be potent non-competitive inhibitors of pyruvate oxidation in castor-bean mitochondria. The accumulation of pyruvate by castor-bean mitochondria was determined by using a silicone-oil-centrifugation technique. The accumulation was shown to observe Michaelis-Menten kinetics, with a Km for pyruvate of 0.10 mM and a Vmax. of 0.95 nmol/min per mg of mitochondrial protein. However, the observed rates of pyruvate accumulation were insufficient to account for the pyruvate oxidation rates found in the oxygen-electrode studies. We were able to demonstrate that this is due to the immediate export of the accumulated radiolabel in the form of malate and citrate. Compound UK5099 inhibited the accumulation of [2-14C]pyruvate by castor-bean mitochondria at concentrations similar to those required to inhibit pyruvate oxidation.

scholarly journals Reduced efficiency, but increased fat oxidation, in mitochondria from human skeletal muscle after 24-h ultraendurance exercise

2007 ◽  
Vol 102 (5) ◽  
pp. 1844-1849 ◽  
Author(s):  
Maria Fernström ◽  
Linda Bakkman ◽  
Michail Tonkonogi ◽  
Irina G. Shabalina ◽  
Zinaida Rozhdestvenskaya ◽  
...  
Keyword(s):  
Electron Transport ◽  
Electron Transport Chain ◽  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Oxygen Demand ◽  
Atp Synthesis ◽  
Whole Body ◽  
Palmitoyl Carnitine ◽  
Transport Chain ◽  
Mitochondrial Efficiency

The hypothesis that ultraendurance exercise influences muscle mitochondrial function has been investigated. Athletes in ultraendurance performance performed running, kayaking, and cycling at 60% of their peak O2 consumption for 24 h. Muscle biopsies were taken preexercise (Pre-Ex), postexercise (Post-Ex), and after 28 h of recovery (Rec). Respiration was analyzed in isolated mitochondria during state 3 (coupled to ATP synthesis) and state 4 (noncoupled respiration), with fatty acids alone [palmitoyl carnitine (PC)] or together with pyruvate (Pyr). Electron transport chain activity was measured with NADH in permeabilized mitochondria. State 3 respiration with PC increased Post-Ex by 39 and 41% ( P < 0.05) when related to mitochondrial protein and to electron transport chain activity, respectively. State 3 respiration with Pyr was not changed ( P > 0.05). State 4 respiration with PC increased Post-Ex but was lower than Pre-Ex at Rec ( P < 0.05 vs. Pre-Ex). Mitochondrial efficiency [amount of added ADP divided by oxygen consumed during state 3 (P/O ratio)] decreased Post-Ex by 9 and 6% ( P < 0.05) with PC and PC + Pyr, respectively. P/O ratio remained reduced at Rec. Muscle uncoupling protein 3, measured with Western blotting, was not changed Post-Ex but tended to decrease at Rec ( P = 0.07 vs. Pre-Ex). In conclusion, extreme endurance exercise decreases mitochondrial efficiency. This will increase oxygen demand and may partly explain the observed elevation in whole body oxygen consumption during standardized exercise (+13%). The increased mitochondrial capacity for PC oxidation indicates plasticity in substrate oxidation at the mitochondrial level, which may be of advantage during prolonged exercise.

scholarly journals Activity of alternative oxidase and plant uncoupling mitochondrial protein in potato tubers stored at low temperature or submitted to artificial aging

2004 ◽  
Vol 16 (2) ◽  
pp. 69-76 ◽  
Author(s):  
Hugo Alves Pinheiro ◽  
Regis Borges ◽  
Marco Aurélio Pedron e Silva ◽  
Danilo Cruz Centeno
Keyword(s):  
Low Temperature ◽  
Artificial Aging ◽  
Alternative Oxidase ◽  
Cell Damage ◽  
Solanum Tuberosum L ◽  
Mitochondrial Protein ◽  
Respiratory Control ◽  
Protective Mechanism ◽  
Potato Tubers ◽  
Mitochondrial Oxidative Stress

Potato tubers (Solanum tuberosum L. cv. Binje) were stored at 18 and 4ºC in order to verify changes in mitochondrial metabolism, especially in the activities of the alternative oxidase (AOX) and plant uncoupling mitochondria protein (PUMP). Tubers were also sliced and submitted to artificial aging. The oxygen consumption rate (OCR), respiratory control (RC) and ADP/O ratio for mitochondria obtained after storage at 18ºC were not altered, regardless of the time of storage. Considerable increment in OCR, for both respiratory states 3 and 4, was observed after storing the tubers for five and ten days at 4ºC; and it was accomplished by reductions in RC and ADP/O. The AOX activity was evident after five days at 4ºC, and it was enhanced after ten days of storage at that temperature. No significant changes in PUMP activities were observed after one day at 18ºC or at 4ºC, neither after artificial aging. However, increased swelling of potato mitochondria was observed in the presence of valinomycin and linoleic acid when the tubers were kept at 4ºC for five and ten days. Besides the changes in AOX and PUMP activities, slight alterations in ascorbate peroxidase (APX) and catalase (CAT) activities were observed after storing the tubers at 4ºC for 5 days. The activities of these enzymes were higher after storage at 4ºC for 10 days. The results suggest the combined effect of low temperature and time of exposure in promoting AOX activity, probably as a protective mechanism against cell damage in response to mitochondrial oxidative stress.

Regulatory features of protein synthesis in isolated mitochondria from Artemia embryos

1993 ◽  
Vol 265 (6) ◽  
pp. R1238-R1246 ◽  
Author(s):  
K. E. Kwast ◽  
S. C. Hand
Keyword(s):  
Protein Synthesis ◽  
Adenine Nucleotides ◽  
Protein Biosynthesis ◽  
Chemical Constituents ◽  
Mitochondrial Gene ◽  
Mitochondrial Protein ◽  
Respiratory Control ◽  
Mitochondrial Protein Synthesis ◽  
Isolated Mitochondria ◽  
External Ph

Optimal conditions were developed for measuring rates of protein synthesis in isolated mitochondria from encysted embryos of Artemia franciscana to 1) identify the required chemical constituents, 2) assess the influence of extramitochondrial pH on protein synthesis, and 3) investigate potential mechanisms coordinating nuclear and mitochondrial gene expression. Isolation procedures resulted in intact, highly coupled mitochondria [respiratory control ratio = 6.48 +/- 0.43 (SE), n = 21]. Requirements for maximal rates of protein synthesis, measured as incorporation of [3H]leucine (60 microM), included an oxidizable carbon source (10 mM succinate), adenine nucleotides (1.5 mM ADP), phosphate (10 mM), K+ (125 mM), Mg2+ (10 mM), amino acids (0.3 mM of each), sucrose or trehalose (500 mM), EGTA (1 mM), and bovine serum albumin (1 mg/ml). Rates were linear for 60 min at 25 degrees C (r = 0.99). Fluorography of translated products revealed 13 peptides. Previous research has shown that anoxia-induced acidification of intracellular pH (pHi) results in suppression of protein biosynthesis, as judged by cytochrome-c oxidase synthesis. In the present study, mitochondrial protein synthesis was acutely sensitive to external pH, with 80% inhibition observed by lowering pH from 7.5 to 6.8. Thus acidification of pHi may serve as one intracellular signal contributing to a coordinated suppression of both cytoplasmic and mitochondrial protein synthesis during transitions from active to anoxia-induced quiescent states.

Cold adaptation in guinea pig at level of isolated brown adipocyte

1986 ◽  
Vol 250 (2) ◽  
pp. C228-C235 ◽  
Author(s):  
J. Rafael ◽  
W. Fesser ◽  
D. G. Nicholls
Keyword(s):  
Guinea Pig ◽  
Cold Acclimation ◽  
Guinea Pigs ◽  
Cold Adaptation ◽  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Respiratory Control ◽  
Cell Number ◽  
Brown Adipocyte ◽  
Brown Adipose

Isolated brown adipocytes were prepared from guinea pigs acclimated to 28 degrees C or exposed to 4-8 degrees C for periods of up to 3 wk. Cells from warm-adapted animals retained respiratory control when stimulated with norepinephrine. Cells from guinea pigs exposed to cold for 4-21 days showed a much greater respiratory response to norepinephrine due to enhanced uncoupling rather than enhanced substrate supply. After 7 days of cold acclimation, norepinephrine-stimulated respiration became uncontrolled and was limited only by the maximal respiratory capacity of the mitochondria. Three weeks of cold acclimation were accompanied by a doubling of total cell number, a doubling of the mitochondrial protein per adipocyte, and a sixfold increase in the norepinephrine-stimulated respiration per in situ mitochondrion with no change in respiratory chain capacity. The induction of norepinephrine-stimulated respiration correlated with the appearance of high-affinity purine nucleotide binding sites on the mitochondria, diagnostic of the uncoupling protein. If the results are extrapolated to the whole animal, they indicate that brown adipose tissue makes little contribution to thermogenesis in the warm-adapted guinea pig but may account for most or all the increment seen on cold adaptation.

scholarly journals Changes in Alternative Pathway and Mitochondrial Respiration in Avocado in Response to Elevated Carbon Dioxide Levels

1997 ◽  
Vol 122 (2) ◽  
pp. 245-252 ◽  
Author(s):  
Diana L. Lange ◽  
Adel A. Kader
Keyword(s):  
Mitochondrial Respiration ◽  
Alternative Oxidase ◽  
Alternative Pathway ◽  
Respiratory Control ◽  
Persea Americana ◽  
Isolated Mitochondria ◽  
Harvest Dates ◽  
Avocado Fruit ◽  
Carbon Dioxide Levels

Partially ripened avocado [Persea americana (Mill.) cv. Hass] fruit harvested in either June or Aug. 1994 were kept at 10 °C in air (21% O2), 20% CO2 (17% O2, balance N2), or 40% CO2 (13% O2, balance N2) for 7 to 12 days and then were transferred to air at 10 °C for 2 to 3 days. Mitochondrial respiration was stimulated in response to elevated CO2 treatments at 10 °C. A shift to alternative pathway (Alt) respiration occurred on day 4 in experiments using avocados from both harvest dates, with a return to initial levels in only the 20% CO2-treated fruit (June-harvested fruit after return to air). Elevated CO2 at 20 °C decreased the in vitro O2 consumption of isolated mitochondria compared to mitochondria kept in air. The Alt pathway contributed less to the total O2 uptake of CO2-treated mitochondria compared to mitochondria kept in air. The respiratory control ratios of the CO2-treated fruit and mitochondria were higher and lower, respectively, than the air controls. Induction of 33 to 37 kD proteins (corresponding to the size of the alternative oxidase proteins) occurred in avocados after 4 days in 40% CO2. These results indicate that elevated CO2 has various effects depending on concentration, duration and temperature of exposure, and mitochondrial function of avocado fruit, such as increased and altered respiratory oxidation and up-regulation of alternative oxidase proteins.

scholarly journals Differential Association of Uncoupling Protein 2 Polymorphisms with Pattern Identification among Korean Stroke Patients: A Diagnostic System in Traditional Korean Medicine

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ji Hye Lim ◽  
Mi Mi Ko ◽  
Hoyoung Lee ◽  
Ho Yeon Go ◽  
Tae-Woong Moon ◽  
...  
Keyword(s):  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Diagnostic System ◽  
Cell Types ◽  
Pattern Identification ◽  
Uncoupling Protein 2 ◽  
Stroke Patients ◽  
Standard Pattern ◽  
Yin Deficiency ◽  
Predictive Parameters

Uncoupling protein 2 (UCP2), a mitochondrial protein present in many organs and cell types, is known to dissipate the proton gradient formed by the electron transport chain. Its function is correlated with predictive parameters, such as obesity, diabetes, and metabolic syndromes. We analyzed the distribution of UCP2 polymorphisms in stroke patients diagnosed with one of the following four stroke subtypes based on the TKM standard pattern identification (PI): Qi-deficiency (QD), Dampness and Phlegm (D&P), Yin-deficiency (YD), and Fire and Heat (F&D). We studied a total of 1,786 stroke patients (397/QD, 645/D&P, 223/YD, and 522/F&D, 586/normal). Genotyping for the G-1957A, G-866A and A55V UCP2 polymorphisms was performed using the TaqMan. G-866A and A55V were significantly associated with the D&P and H&F subtypes. The frequency of subjects with the A allele of G-866A was significantly lower than the frequency of subjects with the GG type. The A55V polymorphism was also shown similar effect with G-866A in the dominant model. In contrast, no SNPs were shown to be associated with the QD or YD subtypes in this study. These results showed that the G-866A and A55V UCP2 polymorphisms may be genetic factors for specific PI types among Korean stroke patients.

scholarly journals Linoleic Acid-induced Activity of Plant Uncoupling Mitochondrial Protein in Purified Tomato Fruit Mitochondria during Resting, Phosphorylating, and Progressively Uncoupled Respiration

1998 ◽  
Vol 273 (52) ◽  
pp. 34882-34886 ◽  
Author(s):  
Wieslawa Jarmuszkiewicz ◽  
Andrea Miyasaka Almeida ◽  
Claudine M. Sluse-Goffart ◽  
Francis E. Sluse ◽  
Anibal E. Vercesi
Keyword(s):  
Linoleic Acid ◽  
Tomato Fruit ◽  
Mitochondrial Protein ◽  
Plant Uncoupling Mitochondrial Protein

scholarly journals Existence of uncoupling protein-2 antigen in isolated mitochondria from various tissues

FEBS Letters ◽  
1999 ◽  
Vol 455 (1-2) ◽  
pp. 79-82 ◽  
Author(s):  
Petr Ježek ◽  
Markéta Žáčková ◽  
Zuzana Řeháková ◽  
Michal Růžička ◽  
Jiří Borecký ◽  
...  
Keyword(s):  
Uncoupling Protein ◽  
Uncoupling Protein 2 ◽  
Isolated Mitochondria
Sign in / Sign up

Export Citation Format

Share Document