Cloning and functional characterization of two cDNAs encoding NADPH-dependent 3-ketoacyl-CoA reductased from developing cotton fibers
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...
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Published in | Cell research Vol. 15; no. 6; pp. 465 - 473 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Nature Publishing Group
01.06.2005
National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University,Beijing, 100871, China Department of Biochemistry and Molecular Biology, College of Life Sciences, Peking University, Beijing, 100871, China%Biocenter Oulu and Department of Biochemistry, University of Oulu, P.O. Box 3000, FIN-90014 University of Oulu, Finland |
Subjects | |
Online Access | Get full text |
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Summary: | 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 ybr159wD mutant that was deficient in 3-ketoacyl-CoA reductase activity. Wild-type growth rate was restored in ybr159wD cells that expressed either GhKCR1 or 2. Further analysis showed that GhKCR1 and 2 were co-sedimented within the membranous pellet fraction after high-speed centrifugation, similar to the yeast endoplasmic reticulum marker ScKar2p. Both GhKCR(s) showed NADPH-dependent 3-ketoacyl-CoA reductase activity in an in vitro assay system using palmitoyl-CoA and malonyl-CoA as substrates. Our results suggest that GhKCR1 and 2 are functional orthologues of ScYbr159p. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 1001-0602 1748-7838 |
DOI: | 10.1038/sj.cr.7290315 |