Brown-adipose-tissue mitochondria: the regulation of the 32 000-Mr uncoupling protein by fatty acids and purine nucleotides
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The increased proton permeability induced by the addition of a synthetic proton translocator to non-respiring hamster brown-fat mitochondria is unaffected by purine nucleotide addition, and the permeabilityinduced by fatty acids is inhibited by nucleotide, indicating that fatty acids act at the 32000-Mr uncoupling protein.Abstract:
The increased proton permeability induced by the addition of a synthetic proton translocator to non-respiring hamster brown-fat mitochondria is unaffected by purine nucleotide addition. In contrast the permeability induced by fatty acids is inhibited by nucleotide, indicating that fatty acids act at the 32000-Mr uncoupling protein. Fatty acids lower the affinity of nucleotide binding to the 32000-Mr protein, but not sufficiently to explain their uncoupling action. The sensitivity of the fatty acid modulation of permeability is dependent on chain length, extent of unsaturation and pH. There is a requirement for an unesterified carboxyl group. In respiring mitochondria fatty acids act in the presence of nucleotide by lowering the 'break-point' potential at which the conductance of the 32000-Mr protein increases. Fatty acids have no effect on the chloride uniport activity of the 32000-Mr protein, but decouple the interference between chloride and protons when the simultaneous transport of both ions is attempted.read more
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Brown Adipose Tissue: Function and Physiological Significance
Barbara Cannon,Jan Nedergaard +1 more
TL;DR: The development of brown adipose tissue with its characteristic protein, uncoupling protein-1 (UCP1), was probably determinative for the evolutionary success of mammals, as its thermogenesis enhances neonatal survival and allows for active life even in cold surroundings.
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Mitochondrial dynamics in the regulation of nutrient utilization and energy expenditure.
TL;DR: Placement of bioenergetic adaptation and quality control as competing tasks of mitochondrial dynamics might provide a new mechanism, linking excess nutrient environment to progressive mitochondrial dysfunction, common to age-related diseases.
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Mechanism of Fatty-Acid-Dependent UCP1 Uncoupling in Brown Fat Mitochondria
TL;DR: It is shown that UCP1 is an LCFA anion/H(+) symporter that effectively operates as an H(+) carrier activated by LCFA, and a similar LCFA-dependent mechanism of transmembrane H(+, transport may be employed by other SLC25 members and be responsible for mitochondrial uncoupling and regulation of metabolic efficiency in various tissues.
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Thermogenic mechanisms and their hormonal regulation.
TL;DR: The mechanisms used by homeothermic species to generate more heat and their regulation largely by thyroid hormone and the sympathetic nervous system are reviewed, finding that thyroid hormone plays a critical role in modulating the amount of the active TH, T(3), in BAT, thereby modulated the responses to SNS.
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Intrinsic and extrinsic uncoupling of oxidative phosphorylation
TL;DR: In this article, the extrinsic uncoupling of OxPhos in mitochondria has been studied based on the induction of a proton leak across the inner membrane, and two mechanisms of respiratory control are described.
References
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Journal ArticleDOI
Nonshivering thermogenesis in the rat. II. Measurements of blood flow with microspheres point to brown adipose tissue as the dominant site of the calorigenesis induced by noradrenaline.
D O Foster,M L Frydman +1 more
TL;DR: Flow to heart and to muscles involved in respiratory movements was two to five times greater during calorigenesis and flow to most other tissues and organs increased or decreased by less than 40%.
Journal ArticleDOI
Effect of surface active agents on the latent ATPASE of mitochondira
TL;DR: In previous work a heat-stable, acetone-soluble fraction from rat liver microsomes was found to stimulate the respiration of mitochondria by means of an assay system based on the activation of latent mitochondrial ATPase, the active component of the microsomal extract has been identified as free fatty acids.
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Brown-Adipose-Tissue Mitochondria: Photoaffinity Labelling of the Regulatory Site of Energy Dissipation
TL;DR: The levels of the 32000-Mr protein in the inner membrane of guinea-pig brown-adipose-tissue mitochondria correlate with the degree of thermogenic adaptation of the animal.