TY  - JOUR
A1  - Morschhäuser, J.
A1  - Uhlin, B. E.
A1  - Hacker, Jörg
T1  - Transcriptional analysis and regulation of the sfa determinant coding for S fimbria of pathogenic E. coli strains
N2  - The sfa determinant codes for S fimbrial adhesins which constitute adherence factors of pathogenic Escherichia coli strains. Wehave recently shown that the sfa determinant is transcribed from three prömoters, pA, pB, and pC. In comparison with the promoters pB and pC, promoter pA, which is located in front of the structural gene sfaA, showed very weak activity. Herewe have determined the exact positions ofthe mRNA start points by primer extension studies. We have also shown that mRNAs of 500, 700 and 1400 bases can be detected using oligonucleotide probes specific for the genes sfaB, sfaC and sfaA. SfaB and SfaC arepositive regulators infiuencing fimbriation and the production of the S-specific adhesin which is encoded by the gene sfaS Iocated in the distal half of the determinant. In addition, it is demonstrated that SfaB and SfaC interfere with the regulatory effect of the histone-like protein H-NS, encoded by a locus termed drdX or osmZ. In a drdx+ strain the regulators are necessary for transcription of the sfa determinant. In contrast, sfa expression is activator-independent in a drdx- strain. In this latter genetic background, a substantial fraction of the sfa transcripts is initiated from promoter pA. On the basis of these data we discuss a model for the regulation of this adhesin-specific determinant.
KW  - Infektionsbiologie
KW  - Gene regulation
KW  - Fimbriae
KW  - Adhesion
KW  - Transcription
KW  - trans-activation
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59844
ER  - 
TY  - JOUR
A1  - Wohlfarth, Carolin
A1  - Schmitteckert, Stefanie
A1  - Härtle, Janina D.
A1  - Houghton, Lesley A.
A1  - Dweep, Harsh
A1  - Fortea, Marina
A1  - Assadi, Ghazaleh
A1  - Braun, Alexander
A1  - Mederer, Tanja
A1  - Pöhner, Sarina
A1  - Becker, Philip P.
A1  - Fischer, Christine
A1  - Granzow, Martin
A1  - Mönnikes, Hubert
A1  - Mayer, Emeran A.
A1  - Sayuk, Gregory
A1  - Boeckxstaens, Guy
A1  - Wouters, Mira M.
A1  - Simrén, Magnus
A1  - Lindberg, Greger
A1  - Ohlsson, Bodil
A1  - Schmidt, Peter Thelin
A1  - Dlugosz, Aldona
A1  - Agreus, Lars
A1  - Andreasson, Anna
A1  - D'Amato, Mauro
A1  - Burwinkel, Barbara
A1  - Bermejo, Justo Lorenzo
A1  - Röth, Ralph
A1  - Lasitschka, Felix
A1  - Vicario, Maria
A1  - Metzger, Marco
A1  - Santos, Javier
A1  - Rappold, Gudrun A.
A1  - Martinez, Cristina
A1  - Niesler, Beate
T1  - miR-16 and miR-103 impact 5-HT4 receptor signalling and correlate with symptom profile in irritable bowel syndrome
JF  - Scientific Reports
N2  - Irritable bowel syndrome (IBS) is a gut-brain disorder involving alterations in intestinal sensitivity and motility. Serotonin 5-HT4 receptors are promising candidates in IBS pathophysiology since they regulate gut motor function and stool consistency, and targeted 5-HT4R selective drug intervention has been proven beneficial in subgroups of patients. We identified a single nucleotide polymorphism (SNP) (rs201253747) c.*61 T > C within the 5-HT4 receptor gene \(HTR4\) to be predominantly present in diarrhoea-IBS patients (IBS-D). It affects a binding site for the miR-16 family and miR-103/miR-107 within the isoforms \({HTR4b/i}\) and putatively impairs \(HTR4\) expression. Subsequent miRNA profiling revealed downregulation of miR-16 and miR-103 in the jejunum of IBS-D patients correlating with symptoms. \(In\) \(vitro\) assays confirmed expression regulation via three 3′UTR binding sites. The novel isoform \(HTR4b\_2\) lacking two of the three miRNA binding sites escapes miR-16/103/107 regulationin SNP carriers. We provide the first evidence that \(HTR4\) expression is fine-tuned by miRNAs, and that this regulation is impaired either by the SNP c.*61 T > C or bydiminished levels of miR-16 and miR-103 suggesting that \(HTR4\) might be involved in the development of IBS-D.
KW  - Medicine
KW  - Gene regulation
KW  - Irritable bowel syndrome
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173478
VL  - 7
ER  -