Nutritional and hormonal regulation of uncoupling protein 2.
Uncoupling proteins (UCPs) belong to a family of mitochondrial carrier proteins that are present in the mitochondrial inner membrane. Genetic and experimental studies have shown that UCP dysfunction can be involved in metabolic disorders and in obesity. Uncoupling protein-1 (UCP1; also known as thermogenin) was identified in 1988 and found to be highly expressed in brown adipose tissue. UCP1 allows the leak of protons in respiring mitochondria, dissipating the energy as heat; the enzyme has an important role in nonshivering heat production induced by cold exposure or food intake. In 1997, two homologs of UCP1 were identified and named UCP2 and UCP3. These novel proteins also lower mitochondrial membrane potential, but whether they can dissipate metabolic energy as heat as efficiently as UCP1 is open to dispute. Even after a decade of study, the physiological roles of these novel proteins have still not been completely elucidated. This review aims to shed light on the nutritional and hormonal regulation of UCP2 and on its physiological roles.
Yonezawa
Tomo
T
Division of Basic Molecular Science and Molecular Medicine, School of Medicine, Tokai University, Bohseidai, Ishehara, Kanagawa, Japan. yonet2301@yahoo.co.jp
Kurata
Riho
R
Hosomichi
Kazuyoshi
K
Kono
Azumi
A
Kimura
Minoru
M
Inoko
Hidetoshi
H
D000273:Adipose Tissue / Q000378:metabolism; D000495:Allosteric Site; D000818:Animals; D004734:Energy Metabolism; D005227:Fatty Acids / Q000737:chemistry; D018390:Gene Targeting; D005973:Glutamine / Q000737:chemistry; D006728:Hormones / Q000378:metabolism; D006801:Humans; D007473:Ion Channels / Q000097:blood*; D008264:Macrophages / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D024101:Mitochondrial Proteins / Q000097:blood*; D052756:Nutritional Sciences; D016366:Open Reading Frames; D014158:Transcription, Genetic; D000071246:Uncoupling Protein 2
D005227:Fatty Acids; D006728:Hormones; D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604389:UCP2 protein, human; D000071246:Uncoupling Protein 2; D005973:Glutamine