2.15-hydroxyeicosatetraenoic acid depressed endothelial nitric oxide synthase activity in pulmonary artery.
Hong YE ; Hai-Rong BI ; Chang-Lian LÜ ; Xiao-Bo TANG ; Da-Ling ZHU
Acta Physiologica Sinica 2005;57(5):612-618
15-hydroxyeicosatetraenoic acid (15-HETE) plays an important role in hypoxia-induced pulmonary vasoconstriction. Release of nitric oxide (NO) is apparently decreased and activity of endothelial nitric oxide synthase (eNOS) is impaired in chronic hypoxia. However, little is known whether 15-HETE contributes to eNOS/NO pathway in the constriction induced by 15-HETE. We examined the response of rat pulmonary artery (PA) rings to 15-HETE, the production of NO, total eNOS expression and the phosphorylation of eNOS in bovine pulmonary artery endothelial cells (BPAECs) stimulated by 15-HETE. Rat PA rings were divided into three groups: endothelium intact group, endothelium denuded group, and nitro-L-arginine methyl ester (L-NAME, 0.1 mmol/L, an inhibitor of eNOS) group. Constrictions to 15-HETE were significantly enhanced in endothelium denuded group and L-NAME group (both P< 0.05 vs endothelium intact group, n= 9); BPAECs were incubated in different conditions to test nitrite production by Greiss method. Nitrite production was significantly reduced by 1 mumol/L 15-HETE (P<0.05), and increased by the lipoxygenase inhibitors, 10 mumol/L cinnamyl 3,4- dihydroxy-[alpha] -cyanocinnamate (CDC, P< 0.05) and 0.1 mmol/L nordihydroguiairetic acid (NDGA, P< 0.01 ); Western blot analysis of extracts from BPAECs incubated with 15-HETE in different time was carried out to test total eNOS expression, and the expression was changed unobviously. Immunoprecipitation (IP) and Western blot analysis of cell extracts from BPAECs treated with 2 mumol/L 15-HETE in different length of time were accomplished, using phospo-eNOS-threonine 495 (Thr495, an inhibitory site) antibody for IP, and eNOS or 15-lipoxygenase (15-LO) antibodies for Western blot. 15-HETE depressed eNOS activity by increasing the levels of phospho-eNOS-Thr 495. The data suggest that eNOS/NO pathway is involved in PA constrictions induced by 15-HETE and that 15-HETE depresses eNOS activity by phosphorylation in Thr495 site. The protein interaction between phospho-eNOS (Thr495) and 15-LO is discovered for the first time.
Animals
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Cattle
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Down-Regulation
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drug effects
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Endothelium, Vascular
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cytology
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drug effects
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enzymology
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Hydroxyeicosatetraenoic Acids
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pharmacology
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In Vitro Techniques
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Male
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Nitric Oxide Synthase Type III
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metabolism
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Pulmonary Artery
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cytology
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enzymology
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physiology
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Rats
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Rats, Wistar
3.The E protein is a multifunctional membrane protein of SARS-CoV.
Qingfa WU ; Yilin ZHANG ; Hong LÜ ; Jing WANG ; Ximiao HE ; Yong LIU ; Chen YE ; Wei LIN ; Jianfei HU ; Jia JI ; Jing XU ; Jie YE ; Yongwu HU ; Wenjun CHEN ; Songgang LI ; Jun WANG ; Jian WANG ; Shengli BI ; Huanming YANG
Genomics, Proteomics & Bioinformatics 2003;1(2):131-144
The E (envelope) protein is the smallest structural protein in all coronaviruses and is the only viral structural protein in which no variation has been detected. We conducted genome sequencing and phylogenetic analyses of SARS-CoV. Based on genome sequencing, we predicted the E protein is a transmembrane (TM) protein characterized by a TM region with strong hydrophobicity and alpha-helix conformation. We identified a segment (NH2-_L-Cys-A-Y-Cys-Cys-N_-COOH) in the carboxyl-terminal region of the E protein that appears to form three disulfide bonds with another segment of corresponding cysteines in the carboxyl-terminus of the S (spike) protein. These bonds point to a possible structural association between the E and S proteins. Our phylogenetic analyses of the E protein sequences in all published coronaviruses place SARS-CoV in an independent group in Coronaviridae and suggest a non-human animal origin.
Amino Acid Sequence
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Base Sequence
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Cluster Analysis
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Codon
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genetics
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Gene Components
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Genome, Viral
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Membrane Glycoproteins
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metabolism
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Membrane Proteins
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genetics
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metabolism
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Molecular Sequence Data
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Phylogeny
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Protein Conformation
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SARS Virus
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genetics
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Sequence Alignment
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Sequence Analysis, DNA
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Sequence Homology
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Spike Glycoprotein, Coronavirus
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Viral Envelope Proteins
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genetics
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metabolism