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Title: X-ray structure of a mammalian stearoyl-CoA desaturase

Authors:
; ; ; ; ; ;  [1];  [2];  [2]
  1. UW
  2. (
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
NIHAHA
OSTI Identifier:
1212210
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nature (London); Journal Volume: 524; Journal Issue: 06, 2015
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Bai, Yonghong, McCoy, Jason G., Levin, Elena J., Sobrado, Pablo, Rajashankar, Kanagalaghatta R., Fox, Brian G., Zhou, Ming, Baylor), and Cornell). X-ray structure of a mammalian stearoyl-CoA desaturase. United States: N. p., 2016. Web. doi:10.1038/nature14549.
Bai, Yonghong, McCoy, Jason G., Levin, Elena J., Sobrado, Pablo, Rajashankar, Kanagalaghatta R., Fox, Brian G., Zhou, Ming, Baylor), & Cornell). X-ray structure of a mammalian stearoyl-CoA desaturase. United States. doi:10.1038/nature14549.
Bai, Yonghong, McCoy, Jason G., Levin, Elena J., Sobrado, Pablo, Rajashankar, Kanagalaghatta R., Fox, Brian G., Zhou, Ming, Baylor), and Cornell). 2016. "X-ray structure of a mammalian stearoyl-CoA desaturase". United States. doi:10.1038/nature14549.
@article{osti_1212210,
title = {X-ray structure of a mammalian stearoyl-CoA desaturase},
author = {Bai, Yonghong and McCoy, Jason G. and Levin, Elena J. and Sobrado, Pablo and Rajashankar, Kanagalaghatta R. and Fox, Brian G. and Zhou, Ming and Baylor) and Cornell)},
abstractNote = {},
doi = {10.1038/nature14549},
journal = {Nature (London)},
number = 06, 2015,
volume = 524,
place = {United States},
year = 2016,
month = 7
}
  • Stearic acid (18:0) is typically a minor component of soybean [Glycine max (L.) Merr.] oil, accounting for only 2 to 4% of the total fatty acid content. Increasing stearic acid levels of soybean oil would lead to enhanced oxidative stability, potentially reducing the need for hydrogenation, a process leading to the formation of undesirable trans fatty acids. Although mutagenesis strategies have been successful in developing soybean germplasm with elevated 18:0 levels in the seed oil, the specific gene mutations responsible for this phenotype were not known. We report a newly identified soybean gene, designated SACPD-C, that encodes a unique isoformmore » of {Delta}{sup 9}-stearoyl-ACP-desaturase, the enzyme responsible for converting stearic acid to oleic acid (18:1). High levels of SACPD-C transcript were only detected in developing seed tissue, suggesting that the encoded desaturase functions to enhance oleic acid biosynthetic capacity as the immature seed is actively engaged in triacylglycerol production and storage. The participation of SACPD-C in storage triacylglycerol synthesis is further supported by the observation of mutations in this gene in two independent sources of elevated 18:0 soybean germplasm, A6 (30% 18:0) and FAM94-41 (9% 18:0). A molecular marker diagnostic for the FAM94-41 SACPD-C gene mutation strictly associates with the elevated 18:0 phenotype in a segregating population, and could thus serve as a useful tool in the development of cultivars with oils possessing enhanced oxidative stability.« less
  • Stearoyl-acyl-carrier-protein (ACP) desaturase was purified to homogeneity from avocado mesocarp, and monospecific polyclonal antibodies directed against the protein were used to isolate full-length cDNA clones from Ricinus communis (castor) seed and Cucumis sativus (cucumber). The nucleotide sequence of the castor clone pRCD1 revealed an open reading frame of 1.2 kilobases encoding a 396-amino acid protein of 45 kDa. The cucumber clone pCSD1 encoded a homologous 396-amino acid protein with 88% amino acid identity to the castor clone. Expression of pRCD1 in Saccharomyces cerevisiae resulted in the accumulation of a functional stearoyl-ACP desaturase, demonstrating that the introduction of this single genemore » product was sufficient to confer soluble desaturase activity to yeast. There was a 48-residue region of 29% amino acid sequence identity between residues 53 and 101 of the castor desaturase and the proximal border of the dehydratase region of the fatty acid synthase from yeast. Stearoyl-ACP mRNA was present at substantially higher levels in developing seeds than in leaf and root tissue, suggesting that expression of the {Delta}{sup 9} desaturase is developmentally regulated.« less
  • The bovine stearoyl-CoA desaturase (Scd) gene plays an important role in the bovine mammary gland where substrates such as stearic and vaccenic acids are converted to oleic acid and conjugated linoleic acid (CLA), respectively. Up to 90% of the CLA in bovine milk is formed due to the action of this enzyme in the mammary gland. The areas of the bovine promoter of importance in regulating this key enzyme were examined and an area of 36 bp in length was identified as having a critical role in transcriptional activation and is designated the Scd transcriptional enhancer element (STE). Electrophoretic mobilitymore » shift assay detected three binding complexes on this area in Mac-T cell nuclear extracts. Treatment of cells with CLA caused a significant reduction in transcriptional activity, with this effect being mediated through the STE region. The bovine Scd gene promoter was up-regulated by insulin and down-regulated by oleic acid.« less