Search results for "PRIMERS"
showing 10 items of 332 documents
Probing suggested catalytic domains of glycosyltransferases by site-directed mutagenesis.
2003
The plant enzyme arbutin synthase isolated from cell suspension cultures of Rauvolfia serpentina and heterologously expressed in Escherichia coli is a member of the NRD1beta family of glycosyltransferases. This enzyme was used to prove, by site-directed mutagenesis, suggested catalytic domains and reaction mechanisms proposed for enzyme-catalyzed glycosylation. Replacement of amino acids far from the NRD domain do not significantly affect arbutin synthase activity. Exchange of amino acids at the NRD site leads to a decrease of enzymatic activity, e.g. substitution of Glu368 by Asp. Glu368, which is a conserved amino acid in glycosyltransferases located at position 2 and is important for enz…
Transfection analysis of expression of mRNA isoforms encoding the nuclear autoantigen La/SS-B
1997
Transcription of the gene encoding for the nuclear autoantigen La resulted in La mRNA isoforms. A promoter switching combined with an alternative splicing pathway replaced the exon 1 with the exon 1'. The exon 1' contained GC-rich regions and an oligo(U) tail of 23 uridine residues. Moreover, it encoded for three open reading frames upstream of the La protein reading frame. Despite this unusual structure, when exon 1' La mRNAs were expressed in transfected cells, both exon 1 and 1' La mRNAs were translated to La protein, whereas the upstream open reading frames of the exon 1' were not translated. In addition to full-length exon 1' La mRNAs 5'-shortened exon 1' La mRNAs were detected. The ex…
Detection of Human Papillomavirus DNA in cervical samples: analysis of the new PGMY-PCR compared to Hybrid Capture II, MY-PCR and a Two-step nested P…
2004
The PGMY-PCR for human papillomavirus (HPV) was evaluated, in parallel with nested PCR (nPCR), in samples with noted Hybrid Capture II (HCII) and MY-PCR results. PGMY-PCR detected HPV DNA in 2.5% of HCII-negative-MY-PCR-negative samples and in 71.7% of HCII-positive-MY-PCR-negative samples; also, it detected the MY-PCR-negative-nPCR-negative types HPV-42, HPV-44, HPV-51, HPV-87, and HPV-89.
Molecular Identification and Mycotoxin Production by Alternaria Species Occurring on Durum Wheat, Showing Black Point Symptoms
2020
Black point is a fungal disease of wheat, mainly associated with mycotoxigenic Alternaria species. Affected wheat kernels are characterized by dark brown discolouration of the embryo region and reduction of grain quality. Potential risk is the possible accumulation of Alternaria mycotoxins, alternariol (AOH), alternariol-monomethyl ether (AME), tenuazonic acid (TA), and altenuene (ALT), provided by haemato-toxic, genotoxic, and mutagenic activities. One hundred and twenty durum wheat samples belonging to 30 different genotypes grown in Bologna and Modena areas, in Italy, showing black point symptoms, were analyzed for Alternaria species and their mycotoxin contamination. Alternariol was sel…
Mutation specific PCR and direct solid phase sequencing assay for the detection of hepatitis B virus pre-C/C mutants in anti-HBe-positive, chronic he…
1994
Sequence analysis of the HBV DNA from patients with anti-HBe+, chronic hepatitis B revealed that the lack of HBeAg is mostly due to a single GA transition at nucleotide position 1896, resulting in a translational stop codon. A point mutation-specific polymerase chain reaction (msPCR) for the detection of this genetic variant was established. Two serologically defined groups of patients with symptomatic chronic hepatitis B (HBeAg+ n = 14, anti-HBe+ n = 11) were included in this study. Viral DNA from 43 sera (26 eAg+/17 anti-HBe+) was amplified twice, using two different sets of PCR primers. Each set contained the same — strand primer, but the + strand primers differed at their 3′-end, thus b…
Identification of ELF3 as an early transcriptional regulator of human urothelium
2014
AbstractDespite major advances in high-throughput and computational modelling techniques, understanding of the mechanisms regulating tissue specification and differentiation in higher eukaryotes, particularly man, remains limited. Microarray technology has been explored exhaustively in recent years and several standard approaches have been established to analyse the resultant datasets on a genome-wide scale. Gene expression time series offer a valuable opportunity to define temporal hierarchies and gain insight into the regulatory relationships of biological processes. However, unless datasets are exactly synchronous, time points cannot be compared directly.Here we present a data-driven ana…
Characterization of Gibberella fujikuroi complex isolates by fumonisin B-1 and B-2 analysis and by RAPD and restriction analysis of PCR-amplified int…
2000
Summary Twenty nine isolates of Fusarium spp. (twenty four of them belonging to the Gibberella fujikuroi complex) isolated from banana and corn from different geographical regions were analyzed for their ability to produce fumonisins B 1 and B 2 and for genetic relatedness using random amplified polymorphic DNA (RAPD) and restriction analysis of PCR amplification products of the 5.8s ribosomal DNA-intervening internal transcribed spacer regions (ITS I-5.8S-ITS II). For RAPD analysis, six of twenty oligonucleotide primers were selected after testing with five Fusarium spp. isolates and used to characterize 24 additional isolates. DNA fragments from the 29 isolates of Fusarium spp., which wer…
Influence of DNA Repair on Nonlinear Dose-Responses for Mutation
2013
Recent evidence has challenged the default assumption that all DNA-reactive alkylating agents exhibit a linear dose-response. Emerging evidence suggests that the model alkylating agents methyl- and ethylmethanesulfonate and methylnitrosourea (MNU) and ethylnitrosourea observe a nonlinear dose-response with a no observed genotoxic effect level (NOGEL). Follow-up mechanistic studies are essential to understand the mechanism of cellular tolerance and biological relevance of such NOGELs. MNU is one of the most mutagenic simple alkylators. Therefore, understanding the mechanism of mutation induction, following low-dose MNU treatment, sets precedence for weaker mutagenic alkylating agents. Here, …
The evolution of the heat-shock protein GroEL from Buchnera, the primary endosymbiont of aphids, is governed by positive selection
2002
The heat-shock protein GroEL is a double-ring-structured chaperonin that assists the folding of many newly synthesized proteins in Escherichia coli and the refolding in vitro, with the cochaperonin GroES, of conformationally damaged proteins. This protein is constitutively overexpressed in the primary symbiotic bacteria of many insects, constituting approximately 10% of the total protein in Buchnera, the primary endosymbiont of aphids. In the present study, we perform a maximum likelihood (ML) analysis to unveil the selective constraints in GroEL. In addition, we apply a new statistical approach to determine the patterns of evolution in this highly interesting protein. The main conclusion d…
Cyclic adenosine monophosphate is a key component of regulatory T cell–mediated suppression
2007
Naturally occurring regulatory T cells (T reg cells) are a thymus-derived subset of T cells, which are crucial for the maintenance of peripheral tolerance by controlling potentially autoreactive T cells. However, the underlying molecular mechanisms of this strictly cell contact–dependent process are still elusive. Here we show that naturally occurring T reg cells harbor high levels of cyclic adenosine monophosphate (cAMP). This second messenger is known to be a potent inhibitor of proliferation and interleukin 2 synthesis in T cells. Upon coactivation with naturally occurring T reg cells the cAMP content of responder T cells is also strongly increased. Furthermore, we demonstrate that natur…