Studies on the global regulator BipA
Studies on the global regulator BipA
This dissertation concerns a novel type of regulatory protein, termed BipA, which is found in many bacteria. BipA regulates a range of cellular processes that influence both the survival and virulence of microorganisms.
It has previously been proposed that BipA directly regulates the translation of another global regulatory protein known as Fis. However, a phenotypic comparison bipA and fis null mutants of E. coli revealed that, while flagella-mediated cell motility was impaired in both mutants, the fis mutant successfully formed colonies at temperatures below 30°C whereas the bipA null mutant did not. These observations indicate the involvement of BipA in processes that are not mediated through Fis. They also suggest that BipA is positioned higher up in the regulatory hierarch than Fis. In addition to comparing bipA and fis phenotypes, the effects of ectopic expression of Fis were studied. Aberrant Fis expression was shown to be deleterious to cell growth, blocking cell division and hence causing filamentation in E. coli.
During the course of this study results were obtained that were inconsistent with the findings presented for the control of Fis expression by BipA. Re-examination of some previously reported data indicates it is unsafe to conclude that BipA directly controls the expression of Fis. In view of these circumstances, a search for additional protein targets that are directly or indirectly regulated by BipA was initiated. Proteomic analysis of lag phase cells from a bipA null mutant of Salmonella enterica serovar Typhimurium and its parent strain uncovered candidate proteins whose expression appears to be influenced by BipA, including SipC, a component associated with the SPI-1 type three secretion system, which is important for virulence in this pathogen.
University of Southampton
Hodey, Michelle Louise
99d5bce7-a6e2-42f9-bfd1-3144beeddd84
2007
Hodey, Michelle Louise
99d5bce7-a6e2-42f9-bfd1-3144beeddd84
Hodey, Michelle Louise
(2007)
Studies on the global regulator BipA.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
This dissertation concerns a novel type of regulatory protein, termed BipA, which is found in many bacteria. BipA regulates a range of cellular processes that influence both the survival and virulence of microorganisms.
It has previously been proposed that BipA directly regulates the translation of another global regulatory protein known as Fis. However, a phenotypic comparison bipA and fis null mutants of E. coli revealed that, while flagella-mediated cell motility was impaired in both mutants, the fis mutant successfully formed colonies at temperatures below 30°C whereas the bipA null mutant did not. These observations indicate the involvement of BipA in processes that are not mediated through Fis. They also suggest that BipA is positioned higher up in the regulatory hierarch than Fis. In addition to comparing bipA and fis phenotypes, the effects of ectopic expression of Fis were studied. Aberrant Fis expression was shown to be deleterious to cell growth, blocking cell division and hence causing filamentation in E. coli.
During the course of this study results were obtained that were inconsistent with the findings presented for the control of Fis expression by BipA. Re-examination of some previously reported data indicates it is unsafe to conclude that BipA directly controls the expression of Fis. In view of these circumstances, a search for additional protein targets that are directly or indirectly regulated by BipA was initiated. Proteomic analysis of lag phase cells from a bipA null mutant of Salmonella enterica serovar Typhimurium and its parent strain uncovered candidate proteins whose expression appears to be influenced by BipA, including SipC, a component associated with the SPI-1 type three secretion system, which is important for virulence in this pathogen.
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Published date: 2007
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Local EPrints ID: 466326
URI: http://eprints.soton.ac.uk/id/eprint/466326
PURE UUID: 9d7261ed-895e-4e4b-bbb2-8e2a93f270ed
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Date deposited: 05 Jul 2022 05:10
Last modified: 16 Mar 2024 20:38
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Author:
Michelle Louise Hodey
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