Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A study of enteroaggregative Escherichia coli (EAggEC) which was recently reported as a causative agent of diarrhea was attempted, by isolating these organisms from the fecal samples collected from sporadic diarrhea patients in Miyazaki Prefecture during the period from January 1993 to April 1998, and by investigating several characteristics of the isolates. By using the PCR method targetting aggR gene which was a transcriptional activator of aggregative adherence fimbria I expression, thirty four strains of aggR(+)-Escherichia coli (E. coli) were detected from 2,652 fecal samples. Twenty nine of these 34 isolates were confirmed as EAggEC by demonstration of aggregative adherence to HEp-2 cells, and the other 5 isolates were not EAggEC because they showed negative adherence to HEp-2 cells. The above mentioned, aggR-PCR method revealed that there were a few non-EAggEC strains with aggR gene. It has been reported that aggregative adherence fimbriae are encoded by the plasmid of about 60 Md. All of the 29 EAggEC isolates possessed plasmids of about 50 Md or more, and these plasmids were suggested to relate to aggregative adherence fimbriae. Sixteen (55%) of the 29 isolates were classified serologically into two serotypes, O111:H21 and O126:H27, and the other 13 isolates were classified into ten groups or more which included a few strains in a group. EAggEC heat-stable enterotoxin 1 (EAST1) gene was demonstrated in nineteen of 29 isolates. In drug susceptibility test, 72%, 59% and 21% of the 29 isolates showed resistance to Ampicillin, Cefazolin, and Streptomycin, respectively.
 ...
PMID:[Detection of enteroaggregative Escherichia coli from sporadic diarrhea patients]. 991 13

Post-translational modification plays crucial roles in signal transduction in eukaryotic cells. To elucidate the biological function of a protein with a specific post-translational modification, it is necessary to isolate the modified protein. However, it is difficult to incorporate a modified amino acid into a specific position of a protein, in particular, in a large-scale preparation. In order to prepare post-translationally modified proteins in Escherichia coli (E. coli), we have constructed co-expression vectors that contain protein and corresponding enzyme genes. The protein and enzyme are co-expressed in the same E. coli cells and the protein is post-translationally modified in vivo. By using this system, the transcriptional activator cyclic-AMP-response-element-binding protein (CREB) was phosphorylated at Ser-133 and the hypoxia-inducible factor-1alpha (HIF-1alpha) was hydroxylated at Asn-803 in E. coli. Although the constructs of the proteins we used are very flexible and susceptible to degradation by proteases in E. coli when they are expressed alone, the B1 domain of streptococcal protein G (GB1) fused to the N-terminus of the proteins increased the yields dramatically. Site-specific phosphorylation of CREB and hydroxylation of HIF-1alpha were confirmed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and NMR. Our GB1-fusion co-expression system can be used in the same way as conventional protein expression in E. coli, making it a flexible and economical method to produce a large amount of a post-translationally modified protein.
 ...
PMID:Overexpression of post-translationally modified peptides in Escherichia coli by co-expression with modifying enzymes. 1805

The delivery of plasmid DNA to target cells using a simple, defined, non-viral system is an area of intense research in gene therapy. Here, we describe a novel DNA carrier protein termed TG, consisting of the DNA-binding domain of the yeast transcriptional activator GAL4 and human immunodeficiency virus type 1 Tat protein, which can transfer modified naked plasmid DNA into target cells to express foreign genes of interest. The TG protein was expressed in Escherichia coli (E. coli), refolded and purified on an immobilized Ni(2+) affinity chromatography column. SDS-PAGE and Western blotting revealed that the fusion protein was highly expressed with a yield of approximately 275 mg/L. We also constructed the pIRES-UAS-EGFP DNA vector, consisting of upstream activating sequences (UASs) for the specific binding of the DNA-binding protein and the enhanced green fluorescent protein (EGFP) gene. The TG protein could bind specifically to pIRES-UAS-EGFP, forming a complex which could efficiently transfect target cells and result in detectable EGFP protein expression. Thus, these results provide a basis for development of efficient non-viral DNA transfer vectors for further improvements of gene therapy strategies.
 ...
PMID:Construction, expression and characterization of a chimeric multi-domain protein mediating specific DNA transfer. 2060 Sep 38

In response to environmental phosphate limitation, the transcriptional activator PhoB of Escherichia coli (E. coli) activates transcription of the phosphate regulon (pho regulon) genes that are involved in phosphate utilization. At least 31 of pho regulon genes have been identified and well characterized in E. coli by numerous studies using non-pathogenic K-12 derivative strains. In this study, we searched for PhoB-regulated promoters from a lacZ-fused genomic library of the E. coli O157:H7 Sakai in an attempt to find novel pho regulon genes in the strain. A promoter region located upstream of a gene cluster (ecs0540-ecs0544) that mapped within one of the strain-specific chromosomal regions of the E. coli O157:H7 was identified. By further in vivo analysis with various subclones of the 5'-flanking region, it was suggested that the ecs0540 transcription was regulated by at least two promoters, an upstream PhoB-regulated promoter and a downstream constitutive promoter. S1 mapping and footprinting experiments revealed two transcription start sites and a sequence similar to the consensus sequence of PhoB binding, respectively. Bioinformatic analysis of the ecs0540-ecs0544 genes showed that these genes were highly homologous to the Escherichia fergusonii (E. fergusonii) siiCA-DA operon encoding a 718 kDa giant protein (SiiEA) and its cognate type I secretion system. In addition, a highly repetitive region and motifs that are shared among RTX (repeats in toxin) toxin family were found in the amino acid sequence of these giant proteins. Our finding is the first example of a member of the pho regulon identified in the O157:H7 strain-specific chromosomal region.
 ...
PMID:Identification and characterization of novel phosphate regulon genes, ecs0540-ecs0544, in Escherichia coli O157:H7. 2064 May 80