scholarly journals Uncoupling proteins in mitochondria of plants and some microorganisms.

2001 ◽  
Vol 48 (1) ◽  
pp. 145-155 ◽  
Author(s):  
W Jarmuszkiewicz
Keyword(s):  
Higher Plants ◽  
Uncoupling Protein ◽  
Physiological Role ◽  
Acanthamoeba Castellanii ◽  
Uncoupling Proteins ◽  
Protein Activity ◽  
Functional Connection ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Carrier Family

Uncoupling proteins, members of the mitochondrial carrier family, are present in mitochondrial inner membrane and mediate free fatty acid-activated, purine-nucleotide-inhibited H+ re-uptake. Since 1995, it has been shown that the uncoupling protein is present in many higher plants and some microorganisms like non-photosynthetic amoeboid protozoon, Acanthamoeba castellanii and non-fermentative yeast Candida parapsilosis. In mitochondria of these organisms, uncoupling protein activity is revealed not only by stimulation of state 4 respiration by free fatty acids accompanied by decrease in membrane potential (these effects being partially released by ATP and GTP) but mainly by lowering ADP/O ratio during state 3 respiration. Plant and microorganism uncoupling proteins are able to divert very efficiently energy from oxidative phosphorylation, competing for deltamicroH+ with ATP synthase. Functional connection and physiological role of uncoupling protein and alternative oxidase, two main energy-dissipating systems in plant-type mitochondria, are discussed.

Uncoupling Proteins: Do They Have a Role in Body Weight Regulation?

Physiology ◽  
2000 ◽  
Vol 15 (6) ◽  
pp. 313-318 ◽  
Author(s):  
Abdul.G. Dulloo ◽  
Sonia Samec
Keyword(s):  
Uncoupling Protein ◽  
Physiological Role ◽  
Uncoupling Proteins ◽  
Weight Regulation ◽  
Body Weight Regulation ◽  
Mitochondrial Carrier ◽  
Adaptive Thermogenesis ◽  
Brown Adipose ◽  
Mitochondrial Carrier Protein

Several members of the mitochondrial carrier protein family are classified as uncoupling proteins. In contrast to the uncoupling protein specific to brown adipose tissue (UCP1), the physiological role of skeletal muscle uncoupling proteins (UCP2 and UCP3) in weight regulation seems more closely associated with the regulation of lipids as fuel substrate than as mediators of adaptive thermogenesis.

Physiological Role of Cyclic Electron Flow in Higher Plants

2012 ◽  
Vol 30 (1) ◽  
pp. 100
Author(s):  
Wei HUANG ◽  
Shi-Bao ZHANG ◽  
Kun-Fang CAO
Keyword(s):  
Higher Plants ◽  
Electron Flow ◽  
Physiological Role ◽  
Cyclic Electron Flow

Biosynthetic mechanism and physiological role of heterocyclic ß-substituted alanines in higher plants

Amino Acids ◽  
1990 ◽  
pp. 1040-1051
Author(s):  
Fumio Ikegami ◽  
Fernand Lambein ◽  
Leslie Fowden ◽  
Isamu Murakoshi
Keyword(s):  
Higher Plants ◽  
Physiological Role

Mitochondrial Uncoupling Proteins in Mammals and Plants

2001 ◽  
Vol 21 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Jirí Borecký ◽  
Ivan G. Maia ◽  
Paulo Arruda
Keyword(s):  
Uncoupling Protein ◽  
Uncoupling Proteins ◽  
Mitochondrial Uncoupling ◽  
Anion Transporter ◽  
Distinct Cluster ◽  
Mitochondrial Uncoupling Proteins ◽  
Shivering Thermogenesis ◽  
General Balance ◽  
Anion Carrier

Uncoupling proteins (UCPs) belong to a distinct cluster of the mitochondrial anion carrier family. Up to five different uncoupling protein types were found in mitochondria of mammals and plants, and recently in fishes, fungi and protozoa. They exhibit a significantly conserved structure with several motifs specific to either the whole cluster or protein type. Uncoupling proteins, as well as the whole mitochondrial anion carrier gene family, probably emerged in evolution before the separation of animal, fungi, and plant kingdoms and originate from an anion/nucleotide or anion/anion transporter ancestor. Mammalian UCP1, UCP2, UCP3, and plant uncoupling proteins pUCP1 and pUCP2 are similar and seem to form one subgroup, whereas UCP4 and BMCP1 belong to a different group. Molecular, biochemical, and phylogenic data suggest that UCP2 could be considered as an UCP-prototype. UCP1 plays its biological role mainly in the non-shivering thermogenesis while the role of the other types is unknown. However, hypotheses have suggested that they are involved in the general balance of basic energy expenditure, protection from reactive oxygen species, and, in plants, in fruit ripening and seed ontogeny.

Physiological role of extracellular ribonucleases of higher plants

2011 ◽  
Vol 1 (1) ◽  
pp. 44-50 ◽  
Author(s):  
S. S. Sangaev ◽  
A. V. Kochetov ◽  
S. S. Ibragimova ◽  
B. A. Levenko ◽  
V. K. Shumny
Keyword(s):  
Higher Plants ◽  
Physiological Role

In Phosphorylating Acanthamoeba castellanii Mitochondria the Sensitivity of Uncoupling Protein Activity to GTP Depends on the Redox State of Quinone

2005 ◽  
Vol 37 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Wieslawa Jarmuszkiewicz ◽  
Aleksandra Swida ◽  
Malgorzata Czarna ◽  
Nina Antos ◽  
Claudine M. Sluse-Goffart ◽  
...  
Keyword(s):  
Redox State ◽  
Uncoupling Protein ◽  
Acanthamoeba Castellanii ◽  
Protein Activity

scholarly journals Glutamine-Derived Aspartate Biosynthesis in Cancer Cells: Role of Mitochondrial Transporters and New Therapeutic Perspectives

Cancers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 245
Author(s):  
Ruggiero Gorgoglione ◽  
Valeria Impedovo ◽  
Christopher L. Riley ◽  
Deborah Fratantonio ◽  
Stefano Tiziani ◽  
...  
Keyword(s):  
Uncoupling Protein ◽  
Cell Metabolism ◽  
Redox Homeostasis ◽  
Nucleotide Biosynthesis ◽  
Specific Tumor ◽  
Mitochondrial Carrier Family ◽  
Cancer Types ◽  
Cancer Cell Metabolism ◽  
Tumor Types

Aspartate has a central role in cancer cell metabolism. Aspartate cytosolic availability is crucial for protein and nucleotide biosynthesis as well as for redox homeostasis. Since tumor cells display poor aspartate uptake from the external environment, most of the cellular pool of aspartate derives from mitochondrial catabolism of glutamine. At least four transporters are involved in this metabolic pathway: the glutamine (SLC1A5_var), the aspartate/glutamate (AGC), the aspartate/phosphate (uncoupling protein 2, UCP2), and the glutamate (GC) carriers, the last three belonging to the mitochondrial carrier family (MCF). The loss of one of these transporters causes a paucity of cytosolic aspartate and an arrest of cell proliferation in many different cancer types. The aim of this review is to clarify why different cancers have varying dependencies on metabolite transporters to support cytosolic glutamine-derived aspartate availability. Dissecting the precise metabolic routes that glutamine undergoes in specific tumor types is of upmost importance as it promises to unveil the best metabolic target for therapeutic intervention.

Uncoupling protein, H+ transport and regulation

2001 ◽  
Vol 29 (6) ◽  
pp. 806-811 ◽  
Author(s):  
M. Klingenberg ◽  
E. Winkler ◽  
K. Echtay
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Heterologous Expression ◽  
Inclusion Bodies ◽  
Uncoupling Protein ◽  
Coenzyme Q ◽  
Uncoupling Proteins ◽  
Expression In Escherichia Coli ◽  
Cl Transport

The biochemical functions of uncoupling proteins (UCPs) are discussed with the view of UCP1 as a paradigm. In contrast with UCP1, the heterologous expression of UCP3 in yeast is found to result primarily in extra-mitochondrial deposits and thus is unsuitable for studying UCP3 function. On expression in Escherichia coli inclusion bodies, UCPs extracted and incorporated into vesicles showed no H+ transport, only Cl– transport. Only after addition of coenzyme Q was fully nucleotide-sensitive high-H+ transport reconstituted, with UCP1 as well as with UCP2 and UCP3. The newly discovered cofactor role of coenzyme Q in H+ transport is proposed to imply co-operation with fatty acids for the injection of H+ into the UCP channel.

Redox state of quinone affects sensitivity of Acanthamoeba castellanii mitochondrial uncoupling protein to purine nucleotides

2008 ◽  
Vol 413 (2) ◽  
pp. 359-367 ◽  
Author(s):  
Aleksandra Swida ◽  
Andrzej Woyda-Ploszczyca ◽  
Wieslawa Jarmuszkiewicz
Keyword(s):  
Respiratory Rate ◽  
Redox State ◽  
Uncoupling Protein ◽  
Acanthamoeba Castellanii ◽  
Inhibitory Effect ◽  
Proton Conductance ◽  
Purine Nucleotides ◽  
Protein Activity ◽  
Mitochondrial Uncoupling ◽  
Quinone Reduction

We studied FFA (free fatty acid)-induced uncoupling activity in Acanthamoeba castellanii mitochondria in the non-phosphorylating state. Either succinate or external NADH was used as a respiratory substrate to determine the proton conductance curves and the relationships between respiratory rate and the quinone reduction level. Our determinations of the membranous quinone reduction level in non-phosphorylating mitochondria show that activation of UCP (uncoupling protein) activity leads to a PN (purine nucleotide)-sensitive decrease in the quinone redox state. The gradual decrease in the rate of quinone-reducing pathways (using titration of dehydrogenase activities) progressively leads to a full inhibitory effect of GDP on LA (linoleic acid) induced proton conductance. This inhibition cannot be attributed to changes in the membrane potential. Indeed, the lack of GDP inhibitory effect observed when the decrease in respiratory rate is accompanied by an increase in the quinone reduction level (using titration of the quinol-oxidizing pathway) proves that the inhibition by nucleotides can be revealed only for a low quinone redox state. It must be underlined that, in A. castellanii non-phosphorylating mitochondria, the transition of the inhibitory effect of GDP on LA-induced UCP-mediated uncoupling is observed for the same range of quinone reduction levels (between 50% and 40%) as that observed previously for phosphorylating conditions. This observation, drawn from the two different metabolic states of mitochondria, indicates that quinone could affect UCP activity through sensitivity to PNs.

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