scholarly journals Yunnan orbivirus, a new orbivirus species isolated from Culex tritaeniorhynchus mosquitoes in China

2005 ◽  
Vol 86 (12) ◽  
pp. 3409-3417 ◽  
Author(s):  
Houssam Attoui ◽  
Fauziah Mohd Jaafar ◽  
Mourad Belhouchet ◽  
Nicolas Aldrovandi ◽  
Sanju Tao ◽  
...  
Keyword(s):  
Cell Lines ◽  
Neutralizing Antibodies ◽  
Yunnan Province ◽  
Coat Proteins ◽  
Outer Coat ◽  
Culex Tritaeniorhynchus ◽  
Specific Pcr ◽  
Mammalian Cell Lines ◽  
Mosquito Cell Lines ◽  
A New Species

An orbivirus designated Yunnan orbivirus (YUOV) was isolated from Culex tritaeniorhynchus mosquitoes collected in the Yunnan province of China. Electron microscopy showed particles with typical orbivirus morphology. The YUOV genome was sequenced completely and compared with previously characterized orbivirus genomes. Significant identity scores were detected between proteins encoded by the segments (Seg-1 to Seg-10) of YUOV and those encoded by their homologues in insect-borne and tick-borne orbiviruses. Analysis of VP1 (Pol) and VP2 (T2, which correlates with the virus serogroup) indicated that YUOV is a new species of the genus Orbivirus that is unrelated to the other insect-borne orbiviruses. The replication of YUOV in mosquito cell lines was restricted to Aedes albopictus cells and the virus failed to replicate in mammalian cell lines. However, intraperitoneal injection of virus into naïve mice resulted in productive, non-lethal virus replication and viraemia. Infected mice developed serum neutralizing antibodies and were protected against a new infection challenge. Sequence analysis of clones from the segments encoding outer coat proteins (Seg-3 and Seg-6) of YUOV recovered from mouse blood did not show significant changes in the sequences. The availability of the complete genome sequence will facilitate the development of sequence-specific PCR assays for the study of YUOV epidemiology in the field.

High Level Expression of Active Human Prothrombin in a Vaccina Virus Expression System

1992 ◽  
Vol 68 (02) ◽  
pp. 119-124 ◽  
Author(s):  
F G Falkner ◽  
P L Turecek ◽  
R T A MacGillivray ◽  
W Bodemer ◽  
F Scheiflinger ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Cell Lines ◽  
Expression System ◽  
Human Cell Line ◽  
Cell System ◽  
Time Saving ◽  
Expression Levels ◽  
Mammalian Cell Lines ◽  
Cell Line Hela ◽  
Virus Expression

SummaryWe have worked out an efficient and time saving procedure for the expression of recombinant human prothrombin. The glycoprotein was expressed in the vaccinia virus expression system in several mammalian cell lines. The kidney cell lines Vero and BHK and the human cell line Hela were found to efficiently secrete prothrombin. Expression levels of 3–4 µg of factor II per 106 cells per day corresponding to 18–23 mU per 106 cells per day were achieved. Since the expression levels obtained with the vaccinia virus/Vero cell system were comparable to those obtained in amplified transformed CHO cells it provides an alternative system for the efficient expression of human prothrombin and may allow to further elucidate structure-function relationships of (pro)thrombin and its various effectors.

SUV39H1-Mediated DNMT1 is Participated in the Epigenetic Regulation of Smad3 in Cervical Cancer

2020 ◽  
Vol 20 ◽  
Author(s):  
Li Zhang ◽  
Sijuan Tian ◽  
Minyi Zhao ◽  
Ting Yang ◽  
Shimin Quan ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Lines ◽  
Epigenetic Regulation ◽  
Promoter Region ◽  
Methylation Status ◽  
Regulation Mechanism ◽  
Methylation Specific Pcr ◽  
Specific Pcr ◽  
Immune Factor ◽  
Cancer Tissues

Background: Smad3 is a pivotal intracellular mediator for participating in the activation of multiple immune signal pathway. Objective: The epigenetic regulation mechanism of the positive immune factor Smad3 in cervical cancer remains unknown. Therefore, the epigenetic regulation on Smad3 is investigated in this study. Methods: The methylation status of SMAD3 was detected by Methylation-specific PCR (MS-PCR) and Quantitative Methylation-specific PCR (MS-qPCR) in cervical cancer tissues and cell lines. The underlying molecular mechanisms of SUV39H1-DNMT1-Smad3 regulation was elucidated using cervical cancer cell lines containing siRNA or/and overexpression system. Confirmation of the regulation of DNMT1 by SUV39H1 used Chromatin immunoprecipitation-qPCR (ChIP-qPCR). The statistical methods used for comparing samples between groups were paired t tests and one-way ANOVAs. Results: H3K9me3 protein which regulated by SUV39H1 directly interacts with the DNMT1 promoter region to regulate its expression in cervical cancer cells, resulting in the reduce expression of the downstream target gene DNMT1. In addition, DNMT1 mediates the epigenetic modulation of the SMAD3 gene by directly binding to its promoter region. The depletion of DNMT1 effectively restores the expression of Smad3 in vitro. Moreover, in an in vivo assay, the expression profile of SUV39H1-DNMT1 was found to correlate with Smad3 expression in accordance with the expression at the cellular level. Notably, the promoter region of SMAD3 was hypermethylated in cervical cancer tissues, and this hypermethylation inhibits the subsequent gene expression. Conclusion: These results indicate that SUV39H1-DNMT1 is a crucial Smad3 regulatory axis in cervical cancer. SUV39H1-DNMT1 axis may provide a potential therapeutic target for the treatment of cervical cancer.

scholarly journals Structure-guided selection of puromycin N-acetyltransferase mutants with enhanced selection stringency for deriving mammalian cell lines expressing recombinant proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alessandro T. Caputo ◽  
Oliver M. Eder ◽  
Hana Bereznakova ◽  
Heleen Pothuis ◽  
Albert Ardevol ◽  
...  
Keyword(s):  
Cell Lines ◽  
Mammalian Cell ◽  
Recombinant Proteins ◽  
Cultured Cells ◽  
Hek293 Cells ◽  
Reaction Products ◽  
Enzyme Form ◽  
X Ray Crystallography ◽  
Mammalian Cell Lines ◽  
Apparent Loss

AbstractPuromycin and the Streptomyces alboniger-derived puromycin N-acetyltransferase (PAC) enzyme form a commonly used system for selecting stably transfected cultured cells. The crystal structure of PAC has been solved using X-ray crystallography, revealing it to be a member of the GCN5-related N-acetyltransferase (GNAT) family of acetyltransferases. Based on structures in complex with acetyl-CoA or the reaction products CoA and acetylated puromycin, four classes of mutations in and around the catalytic site were designed and tested for activity. Single-residue mutations were identified that displayed a range of enzymatic activities, from complete ablation to enhanced activity relative to wild-type (WT) PAC. Cell pools of stably transfected HEK293 cells derived using two PAC mutants with attenuated activity, Y30F and A142D, were found to secrete up to three-fold higher levels of a soluble, recombinant target protein than corresponding pools derived with the WT enzyme. A third mutant, Y171F, appeared to stabilise the intracellular turnover of PAC, resulting in an apparent loss of selection stringency. Our results indicate that the structure-guided manipulation of PAC function can be utilised to enhance selection stringency for the derivation of mammalian cell lines secreting elevated levels of recombinant proteins.

RAS p21 and other Gn proteins are detected in mammalian cell lines by [γ-35S]GTPγS binding

1989 ◽  
Vol 159 (3) ◽  
pp. 1269-1274 ◽  
Author(s):  
J.G. Comerford ◽  
J.R. Gibson ◽  
A.P. Dawson ◽  
I. Gibson
Keyword(s):  
Cell Lines ◽  
Mammalian Cell ◽  
Mammalian Cell Lines ◽  
Gtpγs Binding ◽  
Ras P21

Junewangia aquatica (Junewangiaceae), a new species from freshwater habitats in China

Phytotaxa ◽  
2018 ◽  
Vol 336 (3) ◽  
pp. 272 ◽  
Author(s):  
HAI-YAN SONG ◽  
PING-AN ZHONG ◽  
JIANG-LIN LIAO ◽  
ZHAO-HAI WANG ◽  
DIAN-MING HU ◽  
...  
Keyword(s):  
New Species ◽  
Phylogenetic Tree ◽  
Yunnan Province ◽  
Submerged Wood ◽  
Freshwater Habitats ◽  
A New Species

Junewangia aquatica sp. nov., a new Acrodictys-like fungus was collected on submerged wood from freshwater habitats in Yunnan Province, China. J. aquatica is characterized by its flared conidiophores with percurrent proliferations, monoblastic, terminal or intercalary, cylindrical conidiogenous cells, and subglobose to broadly ellipsoidal conidia with transverse and oblique septa. A phylogenetic tree of Acrodictys-like species was inferred from multi-locus (SSU, ITS and LSU) sequences. A key to the species of Junewangia is provided.

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