|BS||Williams College||Williamstown, Mass.||Biology|
|MS||Case Western Reserve University||Cleveland, Ohio||Biology|
|PhD||University of Wisconsin||Madison, Wis.||Genetics|
The aim of our research is to elucidate molecular mechanisms of transmembrane receptors and sensory transduction. For more than 35 years our research group has provided important information about the transmembrane chemoreceptors and signaling complexes that mediate chemotaxis in Escherichia coli. We have helped make bacterial chemotaxis the best understood signaling system in biology and a favored subject for systems biology. Our experimental approaches combine biochemistry, biophysics and molecular genetics to investigate the “neurobiology” of bacteria.
We investigate processes by which receptors recognize ligand, signal across the membrane, produce intracellular signals, make supramolecular complexes, generate high sensitivity and wide dynamic range, integrate multiple signals, and mediate sensory adaptation. Elucidation of components and mechanisms involved in E. coli chemotaxis has wide impact because this sensory system is a paradigm for those systems that direct motility in the vast taxonomic range of microorganisms, many of which are biologically, medically and commercially important. In addition bacterial chemotaxis is one of the best understood members of the superfamily of “two-component” signaling systems. Such two-component systems contain histidine kinases and phosphorylated response regulators which mediate responses to many environmental signals. They occur across much of the diversity of living things: most prokaryotes, many plants and some single-celled eukaryotes.
Recent projects in the laboratory include structural probing of receptor conformational changes in vivo and in vitro, characterization of receptor arrays in isolated membrane, determination of the relationship between supramolecular interactions and receptor function, definition of the core unit of chemotaxis signaling complexes and isolation of those core units as active complexes. Many of these projects have utilized Nanodiscs, an emerging technology for manipulation of membrane proteins in a water-soluble state. Our work often involves collaboration with leading laboratories in the application of biophysical, structural and modeling approaches to understanding complex biological systems. We will continue this multifaceted strategy of combining different approaches and disciplines. Members of our research group have the opportunity for training and experience in the entire range of these scientific areas.
Current areas of investigation include characterization of functional interactions among transmembrane receptors in supramelecular signaling complexes, identification of the conformational changes of transmembrane signaling by biophysical approaches including single-molecule Fluorescence Resonance Energy Transfer (FRET) and electron paramagnetic resonance (EPR) spectroscopy, determination of the three-dimensional structure of transmembrane chemoreceptors and their signaling complexes by structural electron microscopy, and crystallization of membrane bilayer-embedded chemoreceptors.
Amin, D. N. and Hazelbauer, G.L. Influence of lipid composition on a transmembrane bacterial chemoreceptor. J. Biol. Chem. 287:41697–41705 (2012).
Hazelbauer, G. L. Bacterial chemotaxis: the early years of molecular studies. Ann. Rev. Microbiol. 66:285-303 (2012).
Hazelbauer, G.L. Adaptation by target remodeling. Nature. 484: 173-175 (2012).
Bartelli, N.L. and Hazelbauer, G.L. Direct evidence that the carboxyl terminal sequence of a bacterial chemoreceptor is an unstructured linker and enzyme tether. Protein Sci. 20:1856-66 (2011).
Li, M. and Hazelbauer, G.L. Core unit of chemotaxis signaling complexes. Proc. Natl. Acad. Sci. USA. 108:9390-9395 (2011).
Li, M., Khursigara, C.M., Subramaniam, S. and Hazelbauer, G.L. Chemotaxis Kinase CheA is Activated by Three Neighboring Chemoreceptor Dimers as Effectively as by Receptor Clusters. Mol. Microbiol. 79, 677–685 (2011).
Amin, D. N. and Hazelbauer, G.L. Chemoreceptors in Signaling Complexes: Shifted Conformation and Asymmetric Coupling. Mol. Microbiol. 78:1313–1323 (2010).
Hazelbauer, G.L. and Lai, W.-C. Bacterial chemoreceptors: providing enhanced features to two-component signaling. Curr. Opinion Microbiol. 13:124-132 (2010).
Amin, D. N. and Hazelbauer, G.L. The chemoreceptor dimer is the unit of conformational coupling and transmembrane signaling. J. Bacteriol. 192, 1193-1200 (2010).
Research areas: Transmembrane receptors and sensory transduction in bacterial chemotaxis.
How to apply:
Electronic submission is encouraged, e-mail to email@example.com
Applicants should send CV and names of two references to:
Dr. Gerald Hazelbauer
117 Schweitzer Hall
University of Missouri
Columbia, MO 65211