A NOVEL NORSPERMIDINE RESPONSIVE SIGNALING PATHWAY IN VIBRIO CHOLERAE AFFECTING BIOFILM FORMATION A Thesis by STEVEN RANDOLPH COCKERELL
نویسندگان
چکیده
............................................................................................................................ iv Acknowledgments ............................................................................................................. vi List of Tables ................................................................................................................... viii List of Figures .................................................................................................................... ix Introduction..........................................................................................................................1 Materials and Methods.........................................................................................................9 Results................................................................................................................................22 Discussion .........................................................................................................................38 Discussion .........................................................................................................................38 References Cited ...............................................................................................................45 Biographical Sketch ..........................................................................................................49
منابع مشابه
Elevated levels of the norspermidine synthesis enzyme NspC enhance Vibrio cholerae biofilm formation without affecting intracellular norspermidine concentrations.
Biofilm formation in Vibrio cholerae is in part regulated by norspermidine, a polyamine synthesized by the enzyme carboxynorspermidine decarboxylase (NspC). The absence of norspermidine in the cell leads to a marked reduction in V. cholerae biofilm formation by an unknown mechanism. In this work, we show that overexpression of nspC results in large increases in biofilm formation and vps gene ex...
متن کاملNspS, a predicted polyamine sensor, mediates activation of Vibrio cholerae biofilm formation by norspermidine.
Vibrio cholerae is both an environmental bacterium and a human intestinal pathogen. The attachment of bacteria to surfaces in biofilms is thought to be an important feature of the survival of this bacterium both in the environment and within the human host. Biofilm formation occurs when cell-surface and cell-cell contacts are formed to make a three-dimensional structure characterized by pillars...
متن کاملNorspermidine Is Not a Self-Produced Trigger for Biofilm Disassembly
Formation of Bacillus subtilis biofilms, consisting of cells encapsulated within an extracellular matrix of exopolysaccharide and protein, requires the polyamine spermidine. A recent study reported that (1) related polyamine norspermidine is synthesized by B. subtilis using the equivalent of the Vibrio cholerae biosynthetic pathway, (2) exogenous norspermidine at 25 μM prevents B. subtilis biof...
متن کاملRelative contributions of norspermidine synthesis and signaling pathways to the regulation of Vibrio cholerae biofilm formation
The polyamine norspermidine is one of the major polyamines synthesized by Vibrionales and has also been found in various aquatic organisms. Norspermidine is among the environmental signals that positively regulate Vibrio cholerae biofilm formation. The NspS/MbaA signaling complex detects extracellular norspermidine and mediates the response to this polyamine. Norspermidine binding to the NspS p...
متن کاملVibrio cholerae NspS, a homologue of ABC-type periplasmic solute binding proteins, facilitates transduction of polyamine signals independent of their transport.
The polyamines norspermidine and spermidine are among the environmental signals that regulate Vibrio cholerae biofilm formation. The effects of these polyamines are mediated by NspS, a member of the bacterial periplasmic solute binding protein superfamily. Almost all members of this superfamily characterized to date are components of ATP-binding cassette-type transporters involved in nutrient u...
متن کامل