Plant Uncoupling Mitochondrial Protein and Alternative Oxidase: Energy Metabolism and Stress

2005 ◽  
Vol 25 (3-4) ◽  
pp. 271-286 ◽  
Author(s):  
Jiří Borecký ◽  
Aníbal E. Vercesi
Keyword(s):  
Energy Metabolism ◽  
Alternative Oxidase ◽  
Plant Mitochondria ◽  
Mitochondrial Protein ◽  
Physiological Role ◽  
Mitochondrial Energy Metabolism ◽  
Functional Studies ◽  
Plant Uncoupling Mitochondrial Protein ◽  
And Function

Energy-dissipation in plant mitochondria can be mediated by inner membrane proteins via two processes: redox potential-dissipation or proton electrochemical potential-dissipation. Alternative oxidases (AOx) and the plant uncoupling mitochondrial proteins (PUMP) perform a type of intrinsic and extrinsic regulation of the coupling between respiration and phosphorylation, respectively. Expression analyses and functional studies on AOx and PUMP under normal and stress conditions suggest that the physiological role of both systems lies most likely in tuning up the mitochondrial energy metabolism in response of cells to stress situations. Indeed, the expression and function of these proteins in non-thermogenic tissues suggest that their primary functions are not related to heat production.

Alternative Oxidase and Uncoupling Protein: Thermogenesis Versus Cell Energy Balance

2001 ◽  
Vol 21 (2) ◽  
pp. 213-222 ◽  
Author(s):  
Wieslawa Jarmuszkiewicz ◽  
Claudine M. Sluse-Goffart ◽  
Anibal E. Vercesi ◽  
Francis E. Sluse
Keyword(s):  
Energy Metabolism ◽  
Energy Balance ◽  
Lower Limit ◽  
Alternative Oxidase ◽  
Uncoupling Protein ◽  
Physiological Role ◽  
Mitochondrial Respiratory Chain ◽  
Cell Energy ◽  
Stimulation Of

The physiological role of an alternative oxidase and an uncoupling protein in plant and protists is discussed in terms of thermogenesis and energy metabolism balance in the cell. It is concluded that thermogenesis is restricted not only by a lower-limit size but also by a kinetically-limited stimulation of the mitochondrial respiratory chain.

scholarly journals Autophagy facilitates adaptation of budding yeast to respiratory growth by recycling serine for one-carbon metabolism

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander I. May ◽  
Mark Prescott ◽  
Yoshinori Ohsumi
Keyword(s):  
Protein Expression ◽  
Carbon Metabolism ◽  
Mitochondrial Protein ◽  
Physiological Role ◽  
Degradation Pathway ◽  
Trna Modification ◽  
Respiratory Growth ◽  
One Carbon Metabolism ◽  
And Function

AbstractThe mechanism and function of autophagy as a highly-conserved bulk degradation pathway are well studied, but the physiological role of autophagy remains poorly understood. We show that autophagy is involved in the adaptation of Saccharomyces cerevisiae to respiratory growth through its recycling of serine. On respiratory media, growth onset, mitochondrial initiator tRNA modification and mitochondrial protein expression are delayed in autophagy defective cells, suggesting that mitochondrial one-carbon metabolism is perturbed in these cells. The supplementation of serine, which is a key one-carbon metabolite, is able to restore mitochondrial protein expression and alleviate delayed respiratory growth. These results indicate that autophagy-derived serine feeds into mitochondrial one-carbon metabolism, supporting the initiation of mitochondrial protein synthesis and allowing rapid adaptation to respiratory growth.

Mitochondrial contributions to neuronal development and function

2018 ◽  
Vol 399 (7) ◽  
pp. 723-739 ◽  
Author(s):  
Andrea Princz ◽  
Konstantinos Kounakis ◽  
Nektarios Tavernarakis
Keyword(s):  
Nervous System ◽  
Energy Metabolism ◽  
Neuronal Development ◽  
High Energy ◽  
Neuronal Function ◽  
Mitochondrial Energy Metabolism ◽  
Energy Demands ◽  
Technical Advances ◽  
And Function

AbstractMitochondria are critical to tissues and organs characterized by high-energy demands, such as the nervous system. They provide essential energy and metabolites, and maintain Ca2+balance, which is imperative for proper neuronal function and development. Emerging findings further underline the role of mitochondria in neurons. Technical advances in the last decades made it possible to investigate key mechanisms in neuronal development and the contribution of mitochondria therein. In this article, we discuss the latest findings relevant to the involvement of mitochondria in neuronal development, placing emphasis on mitochondrial metabolism and dynamics. In addition, we survey the role of mitochondrial energy metabolism and Ca2+homeostasis in proper neuronal function, and the involvement of mitochondria in axon myelination.

A critical physiological role of zinc in the structure and function of biomembranes

Life Sciences ◽  
1981 ◽  
Vol 28 (13) ◽  
pp. 1425-1438 ◽  
Author(s):  
William J. Bettger ◽  
Boyd L. O'Dell
Keyword(s):  
Physiological Role ◽  
Structure And Function ◽  
And Function

Stress-Induced Changes in Ubiquinone Concentration and Alternative Oxidase in Plant Mitochondria

2001 ◽  
Vol 21 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Vasily N. Popov ◽  
Albert C. Purvis ◽  
Vladimir P. Skulachev ◽  
Anneke M. Wagner
Keyword(s):  
Alternative Oxidase ◽  
Respiratory Activity ◽  
Plant Mitochondria ◽  
High Oxygen ◽  
Plant Tissues ◽  
Respiration Rates ◽  
Bell Peppers ◽  
Respiration Of Mitochondria ◽  
Induced Changes

We have investigated the influence of stress conditions such as incubation at 4°C and incubation in hyperoxygen atmosphere, on plant tissues. The ubiquinone (Q) content and respiratory activity of purified mitochondria was studied. The rate of respiration of mitochondria isolated from cold-treated green bell peppers (Capsicum annuum L) exceeds that of controls, but this is not so for mitochondria isolated from cold-treated cauliflower (Brassica oleracea L). Treatment with high oxygen does not alter respiration rates of cauliflower mitochondria. Analysis of kinetic data relating oxygen uptake with Q reduction in mitochondria isolated from tissue incubated at 4°C (bell peppers and cauliflowers) and at high oxygen levels (cauliflowers) reveals an increase in the total amount of Q and in the percentage of inoxidizable QH2. The effects are not invariably accompanied by an induction of the alternative oxidase (AOX). In those mitochondria where the AOX is induced (cold-treated bell pepper and cauliflower treated with high oxygen) superoxide production is lower than in the control. The role of reduced Q accumulation and AOX induction in the defense against oxidative damage is discussed.

Structure and Function of the Plant Alternative Oxidase: Its Putative Role in the Oxygen Defence Mechanism

1997 ◽  
Vol 17 (3) ◽  
pp. 319-333 ◽  
Author(s):  
Anneke M. Wagner ◽  
Anthony L. Moore
Keyword(s):  
Oxidative Stress ◽  
Alternative Oxidase ◽  
Structure And Function ◽  
Current Understanding ◽  
Defence Mechanism ◽  
Putative Role ◽  
And Function

Current understanding of the structure and function of the plant alternative oxidase is reviewed. In particular, the role of the oxidase in the protection of tissues against oxidative stress is developed.

scholarly journals Transcript Lifetime Is Balanced between Stabilizing Stem-Loop Structures and Degradation-Promoting Polyadenylation in Plant Mitochondria

2001 ◽  
Vol 21 (3) ◽  
pp. 731-742 ◽  
Author(s):  
Josef Kuhn ◽  
Ulrike Tengler ◽  
Stefan Binder
Keyword(s):  
Plant Mitochondria ◽  
Rna Stability ◽  
Processing System ◽  
Stem Loop ◽  
Functional Studies ◽  
In Vitro Processing ◽  
Rapid Amplification ◽  
And Function

ABSTRACT To determine the influence of posttranscriptional modifications on 3′ end processing and RNA stability in plant mitochondria, peaatp9 and Oenothera atp1 transcripts were investigated for the presence and function of 3′ nonencoded nucleotides. A 3′ rapid amplification of cDNA ends approach initiated at oligo(dT)-adapter primers finds the expected poly(A) tails predominantly attached within the second stem or downstream of the double stem-loop structures at sites of previously mapped 3′ ends. Functional studies in a pea mitochondrial in vitro processing system reveal a rapid removal of the poly(A) tails up to termini at the stem-loop structure but little if any influence on further degradation of the RNA. In contrast 3′ poly(A) tracts at RNAs without such stem-loop structures significantly promote total degradation in vitro. To determine the in vivo identity of 3′ nonencoded nucleotides more accurately, pea atp9 transcripts were analyzed by a direct anchor primer ligation-reverse transcriptase PCR approach. This analysis identified maximally 3-nucleotide-long nonencoded extensions most frequently of adenosines combined with cytidines. Processing assays with substrates containing homopolymer stretches of different lengths showed that 10 or more adenosines accelerate RNA processivity, while 3 adenosines have no impact on RNA life span. Thus polyadenylation can generally stimulate the decay of RNAs, but processivity of degradation is almost annihilated by the stabilizing effect of the stem-loop structures. These antagonistic actions thus result in the efficient formation of 3′ processed and stable transcripts.

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