Sensing environmental cues is critical for bacteria to survive under different environmental conditions. This MERIT extension application proposes continued analyses ofsignal transduction components that are used by bacteria to sense alterations of oxygen tension and light intensity. One crytical oxygen and light regulated metaboUc pathway that we study is the tetrapyrrole biosynthetic pathway that synthesizes important end products heme, vitamin 312 and chlorophyll. We are actively studying how oxygen and light responding signal transduction components control synthesis ofthese tetrapyrroles with a long-term goal ofunderstanding how cells coordinate their synthesis. Our laboratory studies several oxygen and light responding receptors that are present in a wide variety of bacteria including several important pathogens where they are Implicated in controlling virulence. This proposal uses a combination of genetics, biochemistry and structural biology methodologies to obtain detailed understandings of underlying molecular mechanisms used to sense changes in oxygen tension and light intensity. We also study how this information is transmitted to transcription factors that regulate tetrapyrrole gene expression in response to oxygen and light. During the past funding period, the Pi's laboratory successfully transitioned Into the field of structural biology resulting in published crystal structures ofseveral light responding transcription factors that we study. These structural approaches are providing the first detailed understanding of how blue Ught absorption drives alteration in gene expression in bacteria. We are taking similar approaches to obtain a detailed molecular understanding of how a change in oxygen tension is sensed and how this information is used to alter cellular physiology.
This study provides molecular details of how bacteria sense changes in oxygen tension and light intensity that can affect the behaviour, survival and pathogenicity of a broad number of bacterial species.
|Yamamoto, Haruki; Fang, Mingxu; Dragnea, Vladimira et al. (2018) Differing isoforms of the cobalamin binding photoreceptor AerR oppositely regulate photosystem expression. Elife 7:|
|Kumka, Joseph E; Schindel, Heidi; Fang, Mingxu et al. (2017) Transcriptomic analysis of aerobic respiratory and anaerobic photosynthetic states in Rhodobacter capsulatus and their modulation by global redox regulators RegA, FnrL and CrtJ. Microb Genom 3:e000125|
|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|
|Schindel, Heidi S; Bauer, Carl E (2016) The RegA regulon exhibits variability in response to altered growth conditions and differs markedly between Rhodobacter species. Microb Genom 2:e000081|
|Shimizu, Takayuki; Cheng, Zhuo; Matsuura, Katsumi et al. (2015) Evidence that Altered Cis Element Spacing Affects PpsR Mediated Redox Control of Photosynthesis Gene Expression in Rubrivivax gelatinosus. PLoS One 10:e0128446|
|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|
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