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1.
Processing of viral envelope glycoprotein by the endomannosidase pathway: evaluation of host cell specificity 总被引:4,自引:2,他引:2
Endo-alpha-D-mannosidase is an enzyme involved in N-linked oligosaccharide
processing which through its capacity to cleave the internal linkage
between the glucose-substituted mannose and the remainder of the
polymannose carbohydrate unit can provide an alternate pathway for
achieving deglucosylation and thereby make possible the continued formation
of complex oligosaccharides during a glucosidase blockade. In view of the
important role which has been attributed to glucose on nascent
glycoproteins as a regulator of a number of biological events, we chose to
further define the in vivo action of endomannosidase by focusing on the
well characterized VSV envelope glycoprotein (G protein) which can be
formed by the large array of cell lines susceptible to infection by this
pathogen. Through an assessment of the extent to which the G protein was
converted to an endo-beta-N- acetylglucosaminidase (endo H)-resistant form
during a castanospermine imposed glucosidase blockade, we found that
utilization of the endomannosidase-mediated deglucosylation route was
clearly host cell specific, ranging from greater than 90% in HepG2 and PtK1
cells to complete absence in CHO, MDCK, and MDBK cells, with intermediate
values in BHK, BW5147.3, LLC-PK1, BRL, and NRK cell lines. In some of the
latter group the electrophoretic pattern after endo H treatment suggested
that only one of the two N-linked oligosaccharides of the G protein was
processed by endomannosidase. In the presence of the specific
endomannosidase inhibitor, Glcalpha1-->3(1- deoxy)mannojirimycin, the
conversion of the G protein into an endo H- resistant form was completely
arrested. While the lack of G protein processing by CHO cells was
consistent with the absence of in vitro measured endomannosidase activity
in this cell line, the failure of MDBK and MDCK cells to convert the G
protein into an endo H-resistant form was surprising since these cell lines
have substantial levels of the enzyme. Similarly, we observed that
influenza virus hemagglutinin was not processed in castanospermine-treated
MDCK cells. Our findings suggest that studies which rely on glucosidase
inhibition to explore the function of glucose in controlling such critical
biological phenomena as intracellular movement or quality control should be
carried out in cell lines in which the glycoprotein under study is not a
substrate for endomannosidase action.
相似文献
2.
Background
Although cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, the severity of disease is highly variable indicating the influence of modifier genes. The intestines of Cftr deficient mice (CF mice: Cftr tm1Unc ) are prone to obstruction by excessive mucus accumulation and are used as a model of meconium ileus and distal intestinal obstruction syndrome. This phenotype is strongly dependent on the genetic background of the mice. On the C57Bl/6 background, the majority of CF mice cannot survive on solid mouse chow, have inflammation of the small intestine, and are about 30% smaller than wild type littermates. In this work potential modifier loci of the CF intestinal phenotype were identified.Results
CF mice on a mixed genetic background (95% C57Bl/6 and 5% 129Sv) were compared to CF mice congenic on the C57Bl/6 background for several parameters of the intestinal CF phenotype. CF mice on the mixed background exhibit significantly greater survival when fed dry mouse chow, have reduced intestinal inflammation as measured by quantitative RT-PCR for marker genes, have near normal body weight gain, and have reduced mucus accumulation in the intestinal crypts. There was an indication of a gender effect for body weight gain: males did not show a significant improvement at 4 weeks of age, but were of normal weight at 8 weeks, while females showed improvement at both 4 and 8 weeks. By a preliminary genome-wide PCR allele scanning, three regions were found to be potentially associated with the milder phenotype. One on chr.1, defined by marker D1Mit36, one on chr. 9 defined by marker D9Mit90, and one on chr. 10, defined by marker D10Mit14.Conclusion
Potential modifier regions were found that have a positive impact on the inflammatory phenotype of the CF mouse small intestine and animal survival. Identification of polymorphisms in specific genes in these regions should provide important new information about genetic modifiers of the CF intestinal phenotype. 相似文献3.
Phylogeny of the M superhaplogroup inferred from complete mitochondrial genome sequence of Indian specific lineages
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Revathi Rajkumar Jheelam Banerjee Hima Bindu Gunturi R Trivedi VK Kashyap 《Genome biology》2004,6(2):P3
Background
Phylogenetic analysis of human complete mitochondrial DNA sequences has largely contributed to resolving phylogenies and antiquity of different lineages belonging to the majorhaplogroups L, N and M (East-Asian lineages). In the absence of whole mtDNA sequence information of M lineages reported in India that exhibits highest diversity within the sub-continent, the present study was undertaken to provide a detailed analysis of this haplogroup to precisely characterize the lineages and unravel their intricate phylogeny. 相似文献4.
A Puri R Sethi B Singh SK Dwivedi VS Narain RK Saran VK Puri 《Indian pacing and electrophysiology journal》2009,9(3):186-189
A 25-year-old previously asymptomatic pregnant woman at 36 weeks'' gestation was noticed to have repetitive monomorphic ventricular tachycardia. A dilated left ventricle with moderately reduced systolic function was found on echocardiographic examination. This is a very rare presentation of peripartum cardiomyopathy (PPCMP) presenting with repetitive monomorphic ventricular tachycardia. 相似文献
5.
Miguel Montenegro-Nicolini Patricio E. Reyes Miguel O. Jara Parameswara R. Vuddanda Andrónico Neira-Carrillo Nicole Butto Sitaram Velaga Javier O. Morales 《AAPS PharmSciTech》2018,19(8):3376-3387
The buccal mucosa appears as a promissory route for biologic drug administration, and pharmaceutical films are flexible dosage forms that can be used in the buccal mucosa as drug delivery systems for either a local or systemic effect. Recently, thin films have been used as printing substrates to manufacture these dosage forms by inkjet printing. As such, it is necessary to investigate the effects of printing biologics on films as substrates in terms of their physical and mucoadhesive properties. Here, we explored solvent casting as a conventional method with two biocompatible polymers, hydroxypropyl methylcellulose, and chitosan, and we used electrospinning process as an electrospun film fabrication of polycaprolactone fibers due to its potential to elicit mucoadhesion. Lysozyme was used as biologic drug model and was formulated as a solution for printing by thermal inkjet printing. Films were characterized before and after printing by mechanical and mucoadhesive properties, surface, and ultrastructure morphology through scanning electron microscopy and solid state properties by thermal analysis. Although minor differences were detected in micrographs and thermograms in all polymeric films tested, neither mechanical nor mucoadhesive properties were affected by these differences. Thus, biologic drug printing on films was successful without affecting their mechanical or mucoadhesive properties. These results open way to explore biologics loading on buccal films by inkjet printing, and future efforts will include further in vitro and in vivo evaluations. 相似文献
6.
A Rajor R Sharma VK Sood Dr V Ramamurthy 《Journal of industrial microbiology & biotechnology》1996,16(4):237-240
Sawdust, a bulky waste generated by wood processing industries, has very few profitable and ecofriendly uses and poses a problem of proper disposal. Treatment with the fungusVolvariella volvaceae and a dilute solution of urea converted sawdust from a phytoinhibitory material to a phytostimulatory soil conditioner. In different types of soils, the soil conditioner increased the moisture retention and facilitated the cohesive interaction of particles. Analyses of the major biopolymers of sawdust after fungal treatment indicated that levels of cellulose, hemicellulose and lignin decreased; however, these changes did not account for the plant growth stimulatory property attained by this material. 相似文献
7.
Inagaki T Dutchak P Zhao G Ding X Gautron L Parameswara V Li Y Goetz R Mohammadi M Esser V Elmquist JK Gerard RD Burgess SC Hammer RE Mangelsdorf DJ Kliewer SA 《Cell metabolism》2007,5(6):415-425
Peroxisome proliferator-activated receptor α (PPARα) regulates the utilization of fat as an energy source during starvation and is the molecular target for the fibrate dyslipidemia drugs. Here, we identify the endocrine hormone fibroblast growth factor 21 (FGF21) as a mediator of the pleiotropic actions of PPARα. FGF21 is induced directly by PPARα in liver in response to fasting and PPARα agonists. FGF21 in turn stimulates lipolysis in white adipose tissue and ketogenesis in liver. FGF21 also reduces physical activity and promotes torpor, a short-term hibernation-like state of regulated hypothermia that conserves energy. These findings demonstrate an unexpected role for the PPARα-FGF21 endocrine signaling pathway in regulating diverse metabolic and behavioral aspects of the adaptive response to starvation. 相似文献
8.
9.
Background
The Kuki-Chin-Mizo population comprising traditionally endogamous tribal groups residing in the state of Mizoram, India claim their descent from the ten lost tribes of Israel that were exiled by the Assyrians. To ascertain their oral history, we analysed DNA markers comprising 15 autosomal microsatellite markers, 5 biallelic and 20 microsatellite markers on Y-chromosome and the maternally inherited mitochondrial DNA sequence variations on 414 individuals belonging to 5 tribal communities from Mizoram (Hmar, Kuki, Mara, Lai and Lusei). The genetic profiles obtained were compared either with populations sharing Jewish ancestry or with local populations along the probable route of migration of the Jewish ancestry claimant Mizoram tribes. 相似文献10.
Revathi Rajkumar Jheelam Banerjee Hima Bindu Gunturi R Trivedi VK Kashyap 《Genome biology》2005,6(2):1-23