The possible role of isoforms of cytochrome c oxidase subunit VIa in mammalian thermogenesis

Hüttemann, Maik; Frank, Viola; Kadenbach, Bernhard

doi:10.1007/s000180050387

Cited by 18 publications

(23 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No effect of palmitate on proton pumping of the bovine heart enzyme was found after reconstitution in the presence or absence of 1% cardiolipin and containing either 5 m m intraliposomal ADP or ATP (not shown). However, the H + /e – stoichiometry of 1.0, measured with the reconstituted bovine heart enzyme in the presence of 5 m m intraliposomal ADP, decreased to H + /e – = 0.5 in the presence of 5 m m intraliposomal ATP (not shown), as described in previous publications [7–9]. The decrease of H + /e – stoichiometry by palmitate with the kidney enzyme is independent of the intraliposomal nucleotide, as in the presence of either 5 m m intraliposomal ATP or 5 m m ADP the same decrease of H + /e – stoichiometry by palmitate was measured (not shown).…”

Section: Resultssupporting

confidence: 85%

“…The ATP/ADP ratio had no effect on the enzyme from bovine liver, containing subunit VIaL (liver‐type). The H + /e – stoichiometry of reconstituted cytochrome c oxidase from bovine liver and kidney, both containing subunit VIaL [4], was found to be 0.5 under the same conditions where the bovine heart enzyme exhibited a value of 1.0 [8]. The enzymes from turkey heart and liver, both containing the liver‐type of subunit VIa, revealed a H + /e – stoichiometry of 0.5 [9].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Palmitate decreases proton pumping of liver‐type cytochrome c oxidase

Lee¹,

Kadenbach²

2001

European Journal of Biochemistry

View full text Add to dashboard Cite

The H+/e– stoichiometry of reconstituted cytochrome c oxidase from bovine kidney, containing subunit VIaL (liver type), is 0.5 under standard conditions but 1.0 on addition of 1% cardiolipin to the lipid mixture (asolectin). Low concentrations of palmitate (half‐maximal effect at 0.5 µm), but not laurate, myristate, stearate, oleate, 1‐hexadecanol, palmitoyl glycerol and palmitoyl CoA, decreased the H+/e– ratio in the presence of cardiolipin from 1.0 to 0.5, accompanied by an increase of coupled, but not of uncoupled respiration of proteoliposomes. Cardiolipin and palmitate did not influence the H+/e– stoichiometry and respiration of reconstituted cytochrome c oxidase from bovine heart, containing subunit VIaH (heart‐type). The H+/e– stoichiometry of the heart enzyme, however, is decreased from 1.0 to 0.5 by 5 mm intraliposomal ATP (instead of 5 mm ADP). It is assumed that palmitate binds to subunit VIaL. The partial uncoupling of proton pumping in cytochrome c oxidase is suggested to participate in mammalian thermogenesis.

show abstract

Section: Resultssupporting

confidence: 85%

mentioning

confidence: 99%

Palmitate decreases proton pumping of liver‐type cytochrome c oxidase

Lee¹,

Kadenbach²

2001

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…This mechanism operates independent of the allosteric ATP-inhibition and does not result in ROS formation. In the enzyme from heart and skeletal muscle (subunit VIaH) the H + /estoichiometry decreases from 1.0 to 0.5 at high intramitochondrial ATP/ADP ratios with half-maximal extent at ATP/ADP = 100 (Frank and Kadenbach, 1996;Hüttemann et al, 1999). This mechanism was suggested to participate in thermogenesis in muscle at rest (e. g. during sleep).…”

Section: Why Are Two Mechanisms Of Respiratory Control Required?mentioning

confidence: 93%

New Control of Mitochondrial Membrane Potential and ROS Formation A Hypothesis

Lee

Bender²,

Arnold³

et al. 2001

Biological Chemistry

View full text Add to dashboard Cite

A new control of mitochondrial membrane potential delta(psi)m and formation of reactive oxygen species (ROS) is presented, based on allosteric ATP-inhibition of cytochrome c oxidase at high intramitochondrial ATP/ADP ratios. Since the rate of ATP synthesis by the ATP synthase is already maximal at low membrane potentials (100-120 mV), the ATP/ADP ratio will also be maximal at this delta(psi)m (at constant rate of ATP consumption). Therefore the control of respiration by the ATP/ADP-ratio keeps delta(psi)m low. In contrast, the known 'respiratory control' leads to an inhibition of respiration only at high delta(psi)m values (150-200 mV) which cause ROS formation. ATP-inhibition of cytochrome c oxidase is switched on and off by reversible phosphorylation (via cAMP and calcium, respectively). We propose that 'stress hormones' which increase intracellular [Ca2+] also increase delta(psi)m and ROS formation, which promote degenerative diseases and accelerate aging.

show abstract

“…Conversely, COX possessing the heart-type paralog (COX6A-2) is able to adjust the COX H + /e − ratio from 0.5 to 1.0 in response to an increase in the ATP/ADP ratio (Frank and Kadenbach 1996). The ability of a cell to alter proton-pumping efficiency by changing paralogs or introducing an ability to respond to energy status has been hypothesized to be important in thermogenic strategies by uncoupling COX activity from ATP production (Hüttemann et al 1999;Lee and Kadenbach 2001). If the evolution of COX6A is indeed linked to homeothermy, it is noteworthy that birds possess only one paralog for COX6A.…”

Section: Paralogs Of Cox Subunitsmentioning

confidence: 98%

Energy metabolism and cytochrome oxidase activity: linking metabolism to gene expression

Bremer

SniderT.

2014

Can. J. Zool.

View full text Add to dashboard Cite

Modification of mitochondrial content demands the synthesis of hundreds of proteins encoded by nuclear and mitochondrial genomes. The responsibility for coordination of this process falls to nuclear-encoded master regulators of transcription. DNAbinding proteins and coactivators integrate information from energy-sensing pathways and hormones to alter mitochondrial gene expression. In mammals, the signaling cascade for mitochondrial biogenesis can be described as follows: hormonal signals and energetic information are sensed by protein-modifying enzymes that in turn regulate the post-translational modification of transcription factors. Once activated, transcription-factor complexes form on promoter elements of many of the nuclear-encoded mitochondrial genes, recruiting proteins that remodel chromatin and initiate transcription. One master regulator in mammals, PGC-1␣, is well studied because of its role in determining the metabolic phenotype of muscles, but also due to its importance in mitochondria-related metabolic diseases. However, relatively little is known about the role of this pathway in other vertebrates. These uncertainties raise broader questions about the evolutionary origins of the pathway and its role in generating the diversity in muscle metabolic phenotypes seen in nature.Résumé : La modification du contenu mitochondrial nécessite la synthèse de centaines de protéines encodées par les génomes nucléaire et mitochondrial, la coordination de ce processus étant assurée par des maîtres régulateurs de la transcription codés par le génome nucléaire. Des protéines se liant à l'ADN et des coactivateurs intègrent l'information provenant de voies de détection de l'énergie et d'hormones pour ensuite modifier l'expression des gènes mitochondriaux. Chez les mammifères, la cascade de signalisation pour la biogénèse mitochondriale peut être décrite comme suit : des enzymes de modification de protéines détectent des signaux hormonaux et de l'information énergétique et régulent la modification post-traduction des facteurs de transcription. Une fois activés, des complexes de facteurs de transcription se forment sur des éléments promoteurs de nombreux gènes mitochondriaux à encodage nucléaire, recrutant des protéines qui remodèlent la chromatine et amorcent la transcription. Un des maîtres régulateurs chez les mammifères, le PGC-1␣, fait l'objet de nombreuses études en raison de son rôle dans la détermination du phénotype métabolique des muscles, mais aussi en raison de son importance dans les maladies métaboliques associées aux mitochondries. Les connaissances sur le rôle de cette voie chez d'autres vertébrés sont toutefois limitées. Ces incertitudes soulèvent des questions plus larges concernant les origines évolutives de cette voie et son rôle dans la production de la diversité de phénotypes métaboliques musculaires observée dans la nature. [Traduit par la Rédaction]

show abstract

The possible role of isoforms of cytochrome c oxidase subunit VIa in mammalian thermogenesis

Cited by 18 publications

References 54 publications

Palmitate decreases proton pumping of liver‐type cytochrome c oxidase

Palmitate decreases proton pumping of liver‐type cytochrome c oxidase

New Control of Mitochondrial Membrane Potential and ROS Formation A Hypothesis

Energy metabolism and cytochrome oxidase activity: linking metabolism to gene expression

Contact Info

Product

Resources

About