Cloning and functional characterization of two cDNAs encoding NADPH-dependent 3-ketoacyl-C

Cloning and functional characterization of two cDNAs encoding NADPH-dependent 3-ketoacyl-CoA reductased from developing cotton fibers

Yong Mei QIN;Francois MA PUJOL;Yong Hui SHI;Jian Xun FENG;Yi Ming LIU;Alexander J KASTANIOTIS;J Kalervo HILTUNEN;Yu Xian ZHU

【期刊名称】《细胞研究（英文版）》 【年(卷),期】2005(015)006

【摘要】Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulated during early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoA reductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1 and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues,respectively. Quantatitive RT-PCR analysis showed that both these genes were highly preferentially expressed during the cotton fiber elongation period with much lower levels recovered from roots, stems and leaves. GhKCR1 and 2 showed 30%-32% identity to Saccharomyces cerevisiae Ybr159p at the deduced amino acid level. These cotton cDNAs were cloned and expressed in yeast haploid ybr159w△ mutant that was deficient in 3-ketoacyl-CoA reductase activity.Wild-type growth rate was restored in ybr159w△ cells that expressed either GhKCR1 or 2. Further analysis