Intercellular signaling is essential for complex microbial events such as development, pathogenesis and biofilm formation. Myxococcus xanthus is an excellent model bacterium for studying intercellular signaling because of its complex life cycle and coordinated social behaviors. This study focuses on M. xanthus social gliding motility and chemotaxis, a multi-cellular function involved in vegetative swarming and fruiting body formation. Previous studies show that social gliding motility/chemotaxis of M. xanthus involves the complex interactions of three major cellular components: type IV pili (TFP), exopolysacchrides (EPS), and a chemotaxis-like Frz sensory system (Frz). This study aims to understand the genetic and biochemical basis of M. xanthus social gliding motility/chemotaxis.
Three specific aims are proposed in this application.
Aim 1 is to analyze the genetic and biochemical properties of PilA to further understand the role of TFP in S-motility.
Aim 2 is to study the molecular mechanisms associated with temporal and spatial control of EPS production and distribution to further understand the role of EPS in S-motility.
Aim 3 is to explore the interaction between TFP & EPS and its associated biological events. The successful execution of these proposed studies will provide a molecular understanding of the TFP-EPS-Frz-associated social gliding motility and chemotaxis. The findings will reveal insightful biological knowledge about intercellular signaling events during the complex development of M. xanthus. Furthermore, these studies could discover the possible evolutionary connections between flagella based swimming motility and TFP dependent gliding motility. Since TFP, EPS and chemosensory proteins are also the key virulent factors for a variety of pathogenic bacteria during biofilm formation and tissue adherence and invasion, the knowledge gained from this study could also lead to new ways to combat microbial pathogenesis. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM054666-10A1
Application #
7259178
Study Section
Prokaryotic Cell and Molecular Biology Study Section (PCMB)
Program Officer
Rodewald, Richard D
Project Start
1996-08-01
Project End
2011-04-30
Budget Start
2007-05-01
Budget End
2008-04-30
Support Year
10
Fiscal Year
2007
Total Cost
$343,855
Indirect Cost
Name
University of California Los Angeles
Department
Dentistry
Type
Schools of Dentistry
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Hu, Wei; Gibiansky, Maxsim L; Wang, Jing et al. (2016) Interplay between type IV pili activity and exopolysaccharides secretion controls motility patterns in single cells of Myxococcus xanthus. Sci Rep 6:17790
Gibiansky, Maxsim L; Hu, Wei; Dahmen, Karin A et al. (2013) Earthquake-like dynamics in Myxococcus xanthus social motility. Proc Natl Acad Sci U S A 110:2330-5
Pan, Hongwei; He, Xuesong; Lux, Renate et al. (2013) Killing of Escherichia coli by Myxococcus xanthus in aqueous environments requires exopolysaccharide-dependent physical contact. Microb Ecol 66:630-8
Hu, Wei; Lux, Renate; Shi, Wenyuan (2013) Analysis of exopolysaccharides in Myxococcus xanthus using confocal laser scanning microscopy. Methods Mol Biol 966:121-31
Hu, Wei; Li, Lina; Sharma, Shivani et al. (2012) DNA builds and strengthens the extracellular matrix in Myxococcus xanthus biofilms by interacting with exopolysaccharides. PLoS One 7:e51905
Pan, Hongwei; Luan, Jia; He, Xuesong et al. (2012) The clpB gene is involved in the stress response of Myxococcus xanthus during vegetative growth and development. Microbiology 158:2336-43
Hu, Wei; Yang, Zhe; Lux, Renate et al. (2012) Direct visualization of the interaction between pilin and exopolysaccharides of Myxococcus xanthus with eGFP-fused PilA protein. FEMS Microbiol Lett 326:23-30
Hu, Wei; Wang, Jing; McHardy, Ian et al. (2012) Effects of exopolysaccharide production on liquid vegetative growth, stress survival, and stationary phase recovery in Myxococcus xanthus. J Microbiol 50:241-8
Yang, Zhe; Hu, Wei; Chen, Kevin et al. (2011) Alanine 32 in PilA is important for PilA stability and type IV pili function in Myxococcus xanthus. Microbiology 157:1920-8
Hu, Wei; Hossain, Muhaiminu; Lux, Renate et al. (2011) Exopolysaccharide-independent social motility of Myxococcus xanthus. PLoS One 6:e16102

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