Molecular cloning of lamprey uncoupling protein and assessment of its uncoupling activity using a yeast heterologous expression system.
We report the molecular cloning of a novel cDNA fragment from lamprey encoding a 313-amino acid protein that is highly homologous to human uncoupling proteins (UCP). We therefore named the protein lamprey UCP. This lamprey UCP, rat UCP1, human UCP2, and human mitochondrial oxoglutarate carrier were individually expressed in Saccharomyces cerevisiae and the recombinant yeast mitochondria were isolated and assayed for the state 4 respiration rate and proton leak. Only UCP1 showed a strong (3.6-fold increase of the ratio of mitochondrial state 4 respiration rate to FCCP-stimulated fully uncoupled respiration rate) and GDP-inhibitable uncoupling activity, while the uncoupling activities of both UCP2 and lamprey UCP were relatively weak (1.5-fold and 1.4-fold, respectively) and GDP-insensitive. The oxoglutarate carrier had no effect on the studied parameters. In conclusion, the lamprey UCP has a mild, unregulated uncoupling activity in the yeast system, which resembles UCP2, but not UCP1.
Jiangsu Diabetes Research Center, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
Chen
C
Wang
Guoxun
G
Sun
Kun
K
Chen
Zhiyuan
Z
Lv
Shiming
S
Peng
Xueyuan
X
Jiang
Yang
Y
Xiang
Chenyu
C
Zhang
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods*; D006801:Humans; D007473:Ion Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D007798:Lampreys / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010101:Oxygen Consumption; D011522:Protons; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D016415:Sequence Alignment; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2
D007473:Ion Channels; D024101:Mitochondrial Proteins; D011522:Protons; C000604371:UCP1 protein, human; C000604389:UCP2 protein, human; C000604373:Ucp1 protein, rat; C000604391:Ucp2 protein, rat; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2