Sensing environmental cues is critical for bacteria to survive under different environmental conditions. ThisMERIT extension application proposes continued analyses ofsignal transduction components that are used bybacteria to sense alterations of oxygen tension and light intensity. One crytical oxygen and light regulatedmetaboUc pathway that we study is the tetrapyrrole biosynthetic pathway that synthesizes important endproducts heme, vitamin 312 and chlorophyll. We are actively studying how oxygen and light responding signaltransduction components control synthesis ofthese tetrapyrroles with a long-term goal ofunderstanding howcells coordinate their synthesis.Our laboratory studies several oxygen and light responding receptors that are present in a wide variety ofbacteria including several important pathogens where they are Implicated in controlling virulence. This proposaluses a combination of genetics, biochemistry and structural biology methodologies to obtain detailedunderstandings of underlying molecular mechanisms used to sense changes in oxygen tension and lightintensity. We also study how this information is transmitted to transcription factors that regulate tetrapyrrolegene expression in response to oxygen and light. During the past funding period, the Pi's laboratory successfullytransitioned Into the field of structural biology resulting in published crystal structures ofseveral lightresponding transcription factors that we study. These structural approaches are providing the first detailedunderstanding of how blue Ught absorption drives alteration in gene expression in bacteria. We are takingsimilar approaches to obtain a detailed molecular understanding of how a change in oxygen tension is sensedand how this information is used to alter cellular physiology.
This study provides molecular details of how bacteria sense changes in oxygen tension and light intensitythat can affect the behaviour, survival and pathogenicity of a broad number of bacterial species.
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|Fang, Mingxu; Bauer, Carl E (2017) The Vitamin B12-Dependent Photoreceptor AerR Relieves Photosystem Gene Repression by Extending the Interaction of CrtJ with Photosystem Promoters. MBio 8:|
|Shimizu, Takayuki; Shen, Jiangchuan; Fang, Mingxu et al. (2017) Sulfide-responsive transcriptional repressor SqrR functions as a master regulator of sulfide-dependent photosynthesis. Proc Natl Acad Sci U S A 114:2355-2360|
|Cheng, Zhuo; Yamamoto, Haruki; Bauer, Carl E (2016) Cobalamin's (Vitamin B12) Surprising Function as a Photoreceptor. Trends Biochem Sci 41:647-650|
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|Kumka, Joseph E; Bauer, Carl E (2015) Analysis of the FnrL regulon in Rhodobacter capsulatus reveals limited regulon overlap with orthologues from Rhodobacter sphaeroides and Escherichia coli. BMC Genomics 16:895|
|Vermeulen, Arjan J; Bauer, Carl E (2015) Members of the PpaA/AerR Antirepressor Family Bind Cobalamin. J Bacteriol 197:2694-703|
|Cheng, Zhuo; Li, Keran; Hammad, Loubna A et al. (2014) Vitamin B12 regulates photosystem gene expression via the CrtJ antirepressor AerR in Rhodobacter capsulatus. Mol Microbiol 91:649-64|
|Wu, Jiang; Cheng, Zhuo; Reddie, Khalilah et al. (2013) RegB kinase activity is repressed by oxidative formation of cysteine sulfenic acid. J Biol Chem 288:4755-62|
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