POSTER NO: 239

Cloning of Uncoupling Protein cDNA of Tomato Using Rapid Amplification of cDNA Ends

Fang Xiao, Yeqing Sun
Department of Life Science and Engineering, Harbin Institute of Technology, NO92, West Dazhi Street, Nangang District, Harbin City, China

Uncoupling protein (UCP), a mitochondrial inner membrane protein, can mediate mitochondrial proton leak, decrease ATP synthesis and release proton electrochemical gradient as heat. In mammals, UCP can control reactive oxygen species (ROS) production, negatively regulate insulin secretion, and play an important role in obesity and diabetes.

In some plants, like potato, it is reported that UCP possibly contributes to flowering, fruit ripening and resistance to cold. But UCP gene of tomato has not been cloned and its function is largely unknown. We have got high yield mutants of tomato in analysis of physiological and biochemical changes of plant seeds, which have been exposed to space environment in recoverable satellite. In order to investigate UCP's connection with the high yield of tomato mutants, we cloned the UCP cDNA of normal tomato (control). By using 5'RACE and 3'RACE method, a 353bp tomato EST with high homology to UCP was used to obtain the 448bp 5'end sequence and 628bp 3'end sequence. The 1429bp complete cDNA sequence of tomato UCP was obtained. The cDNA contains an open reading frame of 921bp and encodes a predicted polypeptide of 306 amino acids. The predicted polypeptide is 98% identical to potato UCP. Further study of function of this protein in the high yield mutant of tomato is undergoing.