PUBLICATION

Uncoupling protein 1 in fish uncovers an ancient evolutionary history of mammalian nonshivering thermogenesis

Authors
Jastroch, M., Wuertz, S., Kloas, W., and Klingenspor, M.
ID
ZDB-PUB-100304-2
Date
2005
Source
Physiological Genomics   22(2): 150-156 (Journal)
Registered Authors
Keywords
proton leak, brown adipose tissue, common carp, uncoupling protein 2, uncoupling protein 3
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Biological Evolution*
  • Fishes/genetics*
  • Fishes/physiology*
  • Gene Expression Regulation
  • Genome/genetics
  • Ion Channels/genetics
  • Ion Channels/metabolism*
  • Mitochondrial Proteins/genetics
  • Mitochondrial Proteins/metabolism*
  • Molecular Sequence Data
  • Physical Chromosome Mapping
  • RNA, Messenger/genetics
  • RNA, Messenger/metabolism
  • Sequence Alignment
  • Thermogenesis/physiology*
PubMed
15886331 Full text @ Physiol. Genomics
Abstract
Uncoupling proteins (UCPs) increase proton leakage across the inner mitochondrial membrane. Thereby, UCP1 in brown adipose tissue dissipates proton motive force as heat. This mechanism of nonshivering thermogenesis is considered as a monophyletic trait of endothermic placental mammals that emerged about 140 million years ago and provided a crucial advantage for life in the cold. The paralogues UCP2 and UCP3 are probably not thermogenic proteins but convey mild uncoupling, which may serve to reduce the rate of mitochondrial reactive oxygen species production. Both are present in endotherms (mammals and birds), but so far only UCP2 has been identified in ectothermic vertebrates (fish and amphibia). The evolution of UCPs is of general interest in the search for the origin of mammalian UCP1-mediated nonshivering thermogenesis. We here show the presence of UCP1 and UCP3 in ectothermic teleost fish species using comparative genomics, phylogenetic inference, and gene expression analysis. In the common carp (Cyprinus carpio), UCP1 is predominantly expressed in the liver and strongly diminished in response to cold exposure, thus contrasting the cold-induced expression of mammalian UCP1 in brown adipose tissue. UCP3 mRNA is only found in carp skeletal muscle with expression levels increased fivefold in response to fasting. Our findings disprove the monophyletic nature of UCP1 in placental mammals and demonstrate that all three members of the core UCP family were already present before the divergence of ray-finned and lobe-finned vertebrate lineages about 420 million years ago.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping