Disease relevance of ureB

• The objective of this study was to determine (i) if complementation of ureB-negative Helicobacter pylori restores colonization and (ii) if urease is a useful reporter for promoter activity in vivo [1].
• These results establish that poliovirus replicons encoding H. pylori ureB are immunogenic and induce primarily a T helper 1 associated immune response [2].
• In biopsy samples of 110 patients with clinical symptoms of active gastritis, H. pylori was detected by means of the polymerase chain reaction (PCR), using species-specific primers defining a 858 bp DNA fragment of H. pylori urease beta-subunit [3].

High impact information on ureB

• With one exception, each isolate not distinguished from the others by RFLPs in ureA-ureB was distinguished by Mbol digestion of the neighboring 1.7 kb ureC-ureD segment [4].
• Gastric tissues obtained from infected and uninfected cats were evaluated for H. pylori ureB, cagPAI, vacA allele, and oipA and colonization density (urease, histology, and real-time PCR) [5].
• These in vivo and in vitro alpha-chemokine levels showed no significant association with the presence of cagA gene and CagA protein, ureB genotype, or binding capacity to MKN45 or KATO III cells in individual H. pylori isolates [6].
• PCR-RFLP confirmed that there was genetic diversity within the ureB gene with three distinct types, one being well conserved and the other two being variations [7].
• Analysis of the restriction fragment length polymorphism of the ureB-amplified product suggested the presence of different individual "H. heilmannii" strains in the cats and of three distinct strains in the human subject [8].

Biological context of ureB

• Plasmid-free mutagenesis was used to replace ureA and ureB with chloramphenicol acetyltransferase in Hp Strains 11637 and 11916. ureAB null Hp lacked detectable urease activity and did not express UreA or UreB as judged by immunoblotting [9].
• A probe to the putative coding sequence for the active site of the H. pylori ureB subunit hybridized at low intensity to a 2.8-kb fragment of BamHI-HindIII-digested H. felis DNA, suggesting that the sequences were homologous but not identical, a result confirmed from the recently published sequences of ureA and ureB from H. felis [10].
• All isolates were tested for antibiotic resistance and characterised by a novel scheme combining polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the ureA + ureB and 23S rRNA genes, vacA signal and midregion genotypes, and PCR detection of cagA [11].
• Kmr transformants obtained showed the Ure- phenotype, and one transformant, HPT73, was established as a knock-out mutant of the ureB gene by Southern analysis [12].
• Further genetic heterogeneity was assessed with ureA-ureB RFLP [13].

Anatomical context of ureB

• METHODS: DNA was extracted from gastric juice samples collected from 45 subjects and was used to amplify urease B gene (ureB) for H. pylori [14].

Analytical, diagnostic and therapeutic context of ureB

• Mice given three doses of replicons did not develop substantial antibodies to ureB as determined by Western blot analysis using lysates from H. pylori [2].
• Expression of ureB in cells from the replicon was demonstrated by metabolic labeling followed by immunoprecipitation with anti-urease antibodies [2].
• Expression of ureB gene in rice plants was verified by RT-PCR and Western blot analysis using polyclonal human antiserum for transcription and translation levels respectively [15].

References