Molecular Studies of the Mitochondrial Uncoupling Protein
The brown adipocytes play an important role in the regulation of body temperature in hibernating as well as in small and newborn mammals. These thermogenic adipocytes express an Uncoupling Protein — UCP. This mitochondrial carrier, unique to these cells, uncouples mitochondrial ATP synthesis from the respiratory chain activity and is responsible for heat production by brown adipocytes. Besides its important physiological role, UCP is a proton membranous transporter proving the validity of Mitchell’s chemiosmotic theory (Nicholls and Locke 1984, Klingenberg 1990). UCP is also able to transport Cl- ions electrophoretically (Garlid 1990). Both H+ and Cl- transports are inhibited by purine nucleotides and free fatty acids activate H+ translocation (Rial and Nicholls 1989). Another characteristic property of UCP, is that it is a member of an expanding family of mitochondrial ion transporters sharing sequence and structural homologies. In addition to UCP, the main members forming this family are the Adenine Nucleotide Translocator, the Phosphate Carrier and the Oxoglutarate Carrier (Walker 1992).
KeywordsBrown Adipose Tissue Uncouple Protein Brown Adipocyte Mitochondrial Transporter Mitochondrial Uncouple Protein
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