title: AtUCP2: a novel isoform of the mitochondrial uncoupling protein of Arabidopsis thaliana.
abstract: Mitochondrial uncoupling proteins (UCPs) play a central role in adaptive thermogenesis in mammals. The UCPs dissipate the proton gradient formed through respiration without ATP synthesis, and the freed energy is readily converted to heat, helping the animals to maintain their body temperature in cold environments. Recently, it was found that UCPs also function in plant mitochondria. Subsequently, a cDNA clone encoding a UCP in potato was isolated. Whereas the UCP gene constitutes a multigene family in mammals, only a single cDNA sequence has been reported so far for the potato UCP. Moreover, it has been recently suggested that Arabidopsis has only a single nuclear gene for UCP. Here we report the existence of another UCP gene in the Arabidopsis genome, showing for the first time the occurrence of a multigene family for the protein in higher plants. A cDNA analysis of this gene showed that the novel isoform possesses all typical features reported for known UCPs. However, the new gene, unlike the other gene in Arabidopsis and the gene in potato, did not appear to respond to low temperature.
authors.affiliation: Laboratory of Plant Molecular Genetics, Graduate School of Agricultural and Life Sciences, University of Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Nakazono
authors.forename: N
authors.initials: N
authors.lastname: Tsutsumi
authors.forename: A
authors.initials: A
authors.lastname: Hirai
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D003080:Cold Temperature; D018076:DNA, Complementary; D007473:Ion Channels; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D010802:Phylogeny; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D000071246:Uncoupling Protein 2
chemical_list: D018076:DNA, Complementary; D007473:Ion Channels; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D020033:Protein Isoforms; D011506:Proteins; D000071246:Uncoupling Protein 2