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1.
The Kl-3 Loop of the Y Chromosome of Drosophila Melanogaster Binds a Tektin-like Protein 总被引:1,自引:0,他引:1
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Primary spermatocyte nuclei of Drosophila melanogaster exhibit three giant lampbrush-like loops formed by the kl-5, kl-3 and ks-1 Y-chromosome fertility factors. These structures contain and abundantly transcribe highly repetitive, simple sequence DNAs and accumulate large amounts of non-Y-encoded proteins. By immunizing mice with the 53-kD fraction (enriched in β(2)-tubulin) excised from a sodium dodecyl sulfate-polyacrylamide gel loaded with Drosophila testis proteins we raised a polyclonal antibody, designated as T53-1, which decorates the kl-3 loop and the sperm flagellum. Two dimensional immunoblot analysis showed that the T53-1 antibody reacts with a single protein of about 53 kD, different from the tubulins and present both in X/Y and X/O males. Moreover, the antigen recognized by the T53-1 antibody proved to be testis-specific because it was detected in testes and seminal vesicles but not in other male tissues or in females. The characteristics of the protein recognized by the T53-1 antibody suggested that it might be a member of a class of axonemal proteins, the tektins, known to form Sarkosyl-urea insoluble filaments in the wall of flagellar microtubules. Purification of the Sarkosyl-urea insoluble fraction of D. melanogaster sperm revealed that it contains four polypeptides having molecular masses ranging from 51 to 57 kD. One of these polypeptides reacts strongly with the T53-1 antibody but none of them reacts with antitubulin antibodies. These results indicate that the kl-3 loop binds a non-Y encoded, testis-specific, tektin-like protein which is a constituent of the sperm flagellum. This finding supports the hypothesis that the Y loops fulfill a protein-binding function required for the proper assembly of the axoneme components. 相似文献
2.
Melania D'Orazio Raffaella Scotti Laura Nicolini Laura Cervoni Giuseppe Rotilio Andrea Battistoni Roberta Gabbianelli 《BMC microbiology》2008,8(1):166
Background
Highly virulent enterohemorrhagic Escherichia coli O157:H7 strains possess three sodC genes encoding for periplasmic Cu, Zn superoxide dismutases: sodC, which is identical to the gene present in non-pathogenic E. coli strains, and sodC-F1 and sodC-F2, two nearly identical genes located within lambdoid prophage sequences. The significance of this apparent sodC redundancy in E. coli O157:H7 has not yet been investigated. 相似文献3.
Goang-Won Cho Mi-Hwa Kim Seung Hyun Kim Seon-Ah Ha Hyun Kee Kim Sanghee Kim Jin W Kim 《BMC molecular biology》2009,10(1):42-9
Background
Oncogene HCCR-1 functions as a negative regulator of the p53 and contributes to tumorigenesis of various human tissues. However, it is unknown how HCCR-1 contributes to the cellular and biochemical mechanisms of human tumorigenesis. 相似文献4.
Background
We have previously shown that ultraviolet-A (UVA) radiation enhances metastatic lung colonization capacity of B16-F1 melanoma cells. The aim of this study was to examine changes in expression profile of genes in mouse melanoma B16-F1 cells exposed to UVA radiation. 相似文献5.
Background
We have previously reported that glycerol acts as a chemical chaperone to restore the expression of WAF1 in some human cancer cell lines bearing mutant p53. Since the expression of WAF1 is up-regulated by activated wildtype p53, glycerol appears to restore wtp53 function. The aim of the present study is to examine the restoration of heat-induced p53-dependent apoptosis by glycerol in human glioblastoma cells (A-172) transfected with a vector carrying a mutant p53 gene (A-172/mp53 cells) or neo control vector (A-172/neo cells). 相似文献6.
Background
Trichomonosis caused by Trichomonas vaginalis is the number one, non-viral sexually transmitted disease (STD) that affects more than 250 million people worldwide. Immunoglobulin A (IgA) has been implicated in resistance to mucosal infections by pathogens. No reports are available of IgA-reactive proteins and the role, if any, of this class of antibody in the control of this STD. The availability of an IgA monoclonal antibody (mAb) immunoreactive to trichomonads by whole cell (WC)-ELISA prompted us to characterize the IgA-reactive protein of T. vaginalis. 相似文献7.
8.
Background
Burkholderia pseudomallei is the causative agent for melioidosis, a disease with significant mortality and morbidity in endemic regions. Its versatility as a pathogen is reflected in its relatively huge 7.24 Mb genome and the presence of many virulence factors including three Type Three Secretion Systems known as T3SS1, T3SS2 and T3SS3. Besides being a human pathogen, it is able to infect and cause disease in many different animals and alternative hosts such as C. elegans. 相似文献9.
10.
Background
HIV-1 targets human cells expressing both the CD4 receptor, which binds the viral envelope glycoprotein gp120, as well as either the CCR5 (R5) or CXCR4 (X4) co-receptors, which interact primarily with the third hypervariable loop (V3 loop) of gp120. Determination of HIV-1 affinity for either the R5 or X4 co-receptor on host cells facilitates the inclusion of co-receptor antagonists as a part of patient treatment strategies. A dataset of 1193 distinct gp120 V3 loop peptide sequences (989 R5-utilizing, 204 X4-capable) is utilized to train predictive classifiers based on implementations of random forest, support vector machine, boosted decision tree, and neural network machine learning algorithms. An in silico mutagenesis procedure employing multibody statistical potentials, computational geometry, and threading of variant V3 sequences onto an experimental structure, is used to generate a feature vector representation for each variant whose components measure environmental perturbations at corresponding structural positions. 相似文献11.
Kseniya A Golovnina Elena Ya Kondratenko Alexander G Blinov Nikolay P Goncharov 《BMC plant biology》2010,10(1):168
Background
Variability of the VRN1 promoter region of the unique collection of spring polyploid and wild diploid wheat species together with diploid goatgrasses (donor of B and D genomes of polyploid wheats) were investigated. Accessions of wild diploid (T. boeoticum, T. urartu) and tetraploid (T. araraticum, T. timopheevii) species were studied for the first time. 相似文献12.
Dave Siak-Wei Ow Denis Yong-Xiang Lim Peter Morin Nissom Andrea Camattari Victor Vai-Tak Wong 《Microbial cell factories》2010,9(1):22
Background
The overexpression of scFv antibody fragments in the periplasmic space of Escherichia coli frequently results in extensive protein misfolding and loss of cell viability. Although protein folding factors such as Skp and FkpA are often exploited to restore the solubility and functionality of recombinant protein products, their exact impact on cellular metabolism during periplasmic antibody fragment expression is not clearly understood. In this study, we expressed the scFvD1.3 antibody fragment in E. coli BL21 and evaluated the overall physiological and global gene expression changes upon Skp or FkpA co-expression. 相似文献13.
Steve Schoonooghe Vladimir Kaigorodov Monika Zawisza Caroline Dumolyn Jurgen Haustraete Johan Grooten Nico Mertens 《BMC biotechnology》2009,9(1):70
Background
Tumour associated antigens on the surface of tumour cells, such as MUC1, are being used as specific antibody targets for immunotherapy of human malignancies. In order to address the poor penetration of full sized monoclonal antibodies in tumours, intermediate sized antibodies are being developed. The cost-effective and efficient production of these molecules is however crucial for their further success as anti-cancer therapeutics. The methylotropic P. pastoris yeast grows in cheap mineral media and is known for its short process times and the efficient production of recombinant antibody fragments like scFvs, bivalent scFvs and Fabs. 相似文献14.
M. Storari R. von Rohr I. Pertot C. Gessler G.A.L. Broggini 《Journal of applied microbiology》2013,114(4):1193-1200
Aims
To develop two assays based on the loop‐mediated isothermal amplification (LAMP) of DNA for the quick and specific identification of Aspergillus carbonarius and ochratoxigenic strains of the Aspergillus niger clade isolated from grapes.Methods and Results
Two sets of primers were designed based on the polyketide synthase genes involved or putatively involved in ochratoxin A (OTA) biosynthesis in A. carbonarius and A. niger clade. Hydroxynaphthol blue was used as indirect method to indicate DNA amplification. The limit of detection of both assays was comparable to that of a PCR reaction. Specificities of the reactions were tested using DNA from different black aspergilli isolated from grapes. The two LAMP assays were then used to identify A. carbonarius and ochratoxigenic A. niger and A. awamori grown in pure cultures without a prior DNA extraction.Conclusions
The two LAMP assays permitted to quickly and specifically identify DNA from OTA‐producing black aspergilli, as well as isolates grown in pure culture.Significance and Impact of the Study
Monitoring vineyards for the presence of OTA‐producing strains is part of the measures to minimize the occurrence of OTA in grape products. The two LAMP assays developed here could be potentially used to speed the screening process of vineyards for the presence of OTA‐producing black aspergilli. 相似文献15.
Taojun He Fang Zhang Jin Zhang Shanshan Wei Jie Ning Hanmei Yuan Bin Li 《Helicobacter》2023,28(3):e12959
Background and aims
Although Helicobacter pylori is recognized as an extracellular infection bacterium, it can lead to an increase in the number of CD8+ T cells after infection. At present, the characteristics of H. pylori antigen-specific CD8+ T cells and the epitope response have not been elucidated. This study was focused on putative protective antigen UreB to detect specific CD8+ T-cell responses in vitro and screen for predominant response epitopes.Methods
The PBMCs collected from H. pylori-infected individuals were stimulated by UreB peptide pools in vitro to identify the immunodominant CD8+ T-cell epitopes. Furthermore, their HLA restriction characteristics were detected accordingly by NGS. Finally, the relationship between immunodominant responses and appearance of gastric symptoms after H. pylori infection was conducted.Results
UreB-specific CD8+ T-cell responses were detected in H. pylori-infected individuals. Three of UreB dominant epitopes (A-2 (UreB443–451: GVKPNMIIK), B-4 (UreB420–428: SEYVGSVEV), and C-1 (UreB5–13: SRKEYVSMY)) were firstly identified and mainly presented by HLA-A*1101, HLA-B*4001 and HLA-C*0702 alleles, respectively. C-1 responses were mostly occurred in H. pylori-infected subjects without gastric symptoms and may alleviate the degree of gastric inflammation.Conclusions
The UreB dominant epitope-specific CD8+ T-cell response was closely related to the gastric symptoms after H. pylori infection, and the C-1 (UreB5-13) dominant peptides may be protective epitopes. 相似文献16.
A. Nur K. Hirota H. Yumoto K. Hirao D. Liu K. Takahashi K. Murakami T. Matsuo R. Shu Y. Miyake 《Journal of applied microbiology》2013,115(1):260-270
Aims
The aim of this study was to clarify the effects of homologous and heterologous extracellular DNAs (eDNAs) and histone‐like DNA‐binding protein (HLP) on Streptococcus intermedius biofilm development and rigidity.Methods and Results
Formed biofilm mass was measured with 0·1% crystal violet staining method and observed with a scanning electron microscope. The localizations of eDNA and extracellular HLP (eHLP) in formed biofilm were detected by staining with 7‐hydoxyl‐9H‐(1,3‐dichloro‐9,9‐dimethylacridin‐2‐one) and anti‐HLP antibody without fixation, respectively. DNase I treatment (200 U ml?1) markedly decreased biofilm formation and cell density in biofilms. Colocalization of eHLP and eDNA in biofilm was confirmed. The addition of eDNA (up to 1 μg ml?1) purified from Strep. intermedius, other Gram‐positive bacteria, Gram‐negative bacteria, or human KB cells into the Strep. intermedius culture increased the biofilm mass of all tested strains of Strep. intermedius, wild‐type, HLP‐downregulated strain and control strains. In contrast, the addition of eDNA (>1 μg ml?1) decreased the biofilm mass of all Strep. intermedius strains.Conclusions
These findings demonstrated that eDNA and eHLP play crucial roles in biofilm development and its rigidity.Significance and Impact of the Study
eDNA‐ and HLP‐targeting strategies may be applicable to novel treatments for bacterial biofilm‐related infectious diseases. 相似文献17.
Superoxide dismutase from Helicobacter pylori suppresses the production of pro‐inflammatory cytokines during in vivo infection
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Background
Helicobacter pylori has undergone considerable adaptation to allow chronic persistence within the gastric environment. While H. pylori‐associated diseases are driven by an excessive inflammation, severe gastritis is detrimental to colonization by this pathogen. Hence, H. pylori has developed strategies to minimize the severity of gastritis it triggers in its host. Superoxide dismutase (SOD) is well known for its role in protecting against oxidative attack; less recognized is its ability to inhibit immunity, shown for SOD from mammalian sources and those of some bacterial species. This study examined whether H. pylori SOD (HpSOD) has the ability to inhibit the host immune response to these bacteria.Materials and Methods
The ability of recombinant HpSOD to modify the response to LPS was measured using mouse macrophages. A monoclonal antibody against HpSOD was generated and injected into H. pylori‐infected mice.Results
Addition of HpSOD to cultures of mouse macrophages significantly inhibited the pro‐inflammatory cytokine response to LPS stimulation. A monoclonal antibody was generated that was specific for SOD from H. pylori. When injected into mice infected with H. pylori for 3 months, this antibody was readily detected in both sera and gastric tissues 5 days later. While treatment with anti‐HpSOD had no effect on H. pylori colonization at this time point, it significantly increased the levels of a range of pro‐inflammatory cytokines in the gastric tissues. This did not occur with antibodies against other antioxidant enzymes.Conclusions
SOD from H. pylori can inhibit the production of pro‐inflammatory cytokine during in vivo infection. 相似文献18.
Daridon C Blassfeld D Reiter K Mei HE Giesecke C Goldenberg DM Hansen A Hostmann A Frölich D Dörner T 《Arthritis research & therapy》2010,12(6):R204
Introduction
Epratuzumab, a humanized anti-CD22 monoclonal antibody, is under investigation as a therapeutic antibody in non-Hodgkin's lymphoma and systemic lupus erythematosus (SLE), but its mechanism of action on B-cells remains elusive. Treatment of SLE patients with epratuzumab leads to a reduction of circulating CD27negative B-cells, although epratuzumab is weakly cytotoxic to B-cells in vitro. Therefore, potential effects of epratuzumab on adhesion molecule expression and the migration of B-cells have been evaluated. 相似文献19.
Background
Various forms of the so-called loop closure problem are crucial to protein structure prediction methods. Given an N- and a C-terminal end, the problem consists of finding a suitable segment of a certain length that bridges the ends seamlessly. 相似文献20.
Saevarsdottir S Ding B Steinsson K Grondal G Valdimarsson H Alfredsson L Klareskog L Padyukov L 《Arthritis research & therapy》2011,13(2):R65