Control of expression of the ICE R391 encoded UV-inducible cell-sensitising function

Hdl Handle:
http://hdl.handle.net/10147/302718
Title:
Control of expression of the ICE R391 encoded UV-inducible cell-sensitising function
Authors:
Armshaw, Patricia; Pembroke, J T
Citation:
BMC Microbiology. 2013 Aug 29;13(1):195
Issue Date:
29-Aug-2013
URI:
http://dx.doi.org/10.1186/1471-2180-13-195; http://hdl.handle.net/10147/302718
Abstract:
Abstract Background Many SXT/R391-like enterobacterial Integrative Conjugative Elements (ICEs) have been found to express an atypical, recA-dependent, UV-inducible, cell-sensitising phenotype observed as a reduction in post-irradiation cell survival rates in host cells. Characterisation of a complete deletion library of the prototype ICE R391 identified the involvement of three core ICE genes, orfs90/91 encoding a putative transcriptional enhancer complex, and orf43, encoding a putative type IV secretion system, outer membrane-associated, conjugative transfer protein. Results In this study, expression analysis of orf43 indicated that it was up-regulated as a result of UV irradiation in an orfs90/91-dependent manner. Induced expression was found to be controlled from a site preceding the gene which required functional orfs90/91. Expression of orfs90/91 was in turn found to be regulated by orf96, a λ cI-like regulator. Targeted construction of ICE R391 deletions, RT-PCR and qRT-PCR analysis confirmed a regulatory link between orfs90/91 and orf43 while site-directed mutagenesis of orf43 suggested an association with the cell membrane was a prerequisite for the cytotoxic effect. Conclusions Because of the recA-dependence of the effect, we hypothesise that UV induction of RecA results in cleavage of the cI-like ICE-encoded repressor protein, the product of orf96. This in turn allows expression of the transcriptional enhancer complex encoded by orfs90/91, which we conclude stimulates transcription of orf43, whose product is directly responsible for the effect.
Language:
en
Keywords:
GENETICS
Local subject classification:
CELL BIOLOGY

Full metadata record

DC FieldValue Language
dc.contributor.authorArmshaw, Patriciaen_GB
dc.contributor.authorPembroke, J Ten_GB
dc.date.accessioned2013-10-04T14:31:31Z-
dc.date.available2013-10-04T14:31:31Z-
dc.date.issued2013-08-29-
dc.identifier.citationBMC Microbiology. 2013 Aug 29;13(1):195en_GB
dc.identifier.urihttp://dx.doi.org/10.1186/1471-2180-13-195-
dc.identifier.urihttp://hdl.handle.net/10147/302718-
dc.description.abstractAbstract Background Many SXT/R391-like enterobacterial Integrative Conjugative Elements (ICEs) have been found to express an atypical, recA-dependent, UV-inducible, cell-sensitising phenotype observed as a reduction in post-irradiation cell survival rates in host cells. Characterisation of a complete deletion library of the prototype ICE R391 identified the involvement of three core ICE genes, orfs90/91 encoding a putative transcriptional enhancer complex, and orf43, encoding a putative type IV secretion system, outer membrane-associated, conjugative transfer protein. Results In this study, expression analysis of orf43 indicated that it was up-regulated as a result of UV irradiation in an orfs90/91-dependent manner. Induced expression was found to be controlled from a site preceding the gene which required functional orfs90/91. Expression of orfs90/91 was in turn found to be regulated by orf96, a λ cI-like regulator. Targeted construction of ICE R391 deletions, RT-PCR and qRT-PCR analysis confirmed a regulatory link between orfs90/91 and orf43 while site-directed mutagenesis of orf43 suggested an association with the cell membrane was a prerequisite for the cytotoxic effect. Conclusions Because of the recA-dependence of the effect, we hypothesise that UV induction of RecA results in cleavage of the cI-like ICE-encoded repressor protein, the product of orf96. This in turn allows expression of the transcriptional enhancer complex encoded by orfs90/91, which we conclude stimulates transcription of orf43, whose product is directly responsible for the effect.-
dc.language.isoenen
dc.subjectGENETICSen_GB
dc.subject.otherCELL BIOLOGYen_GB
dc.titleControl of expression of the ICE R391 encoded UV-inducible cell-sensitising functionen_GB
dc.language.rfc3066en-
dc.rights.holderPatricia Armshaw et al.; licensee BioMed Central Ltd.-
dc.description.statusPeer Reviewed-
dc.date.updated2013-10-01T19:30:25Z-
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