PROKARYOTIC GENE REGULATION BY LIGHT AND OXYGEN

Summary

Principal Investigator: CARL EUGENE BAUER
Affiliation: Indiana University
Country: USA
Abstract: Alteration in oxygen tension affects gene expression in all cell types. In bacterial systems, oxygen regulates a variety of genes involved in aerobic versus anaerobic energy metabolism. Metabolic processes such as carbon fixation, nitrogen fixation, respiration and photosynthesis are regulated in response to the presence or absence of oxygen. In yeast and algal cells, oxygen is known to affect transcription of oxidative defense genes as well as metabolic enzymes. In mammalian cells, a growing number of genes are known to be oxygen regulated such as vascular growth factors that are key regulators for the synthesis of new capillary sprouts from preexisting vessels. Besides physiological roles, these growth factors are involved in disease processes such as the stimulation of capillary formation during tumor growth. This proposal is centered on elucidating molecular details of how bacteria Rhodobacter capsulatus and Rhodobacter sphaeroides are able to sense changes in oxygen tension, and in response, alter gene expression. These related species are capable of growth in a variety of energy generating modes including aerobic respiration, anaerobic fermentation and photosynthesis. The expression of genes involved in each of these processes are affected by alterations in oxygen tension, as well as by variations in light intensity. Regulation of cell physiology by light is also known to occur in a number of organisms ranging from bacterial to mammals and is a second process that is studied by this proposal. Indeed, one of the key oxygen regulated transcription factors studied in this proposal is also regulated by light intensity. As a model system for studying both oxygen and light regulation of gene expression, we have focused on the process of tetrapyrrole biosynthesis. This pathway is highly regulated by oxygen and light intensity and is responsible for the production of such important metabolites as B12, heme and chlorophylls.
Funding Period: 1989-12-01 - 2011-03-31
more information: NIH RePORT

Top Publications

  1. pmc Crystal structures of the Synechocystis photoreceptor Slr1694 reveal distinct structural states related to signaling
    Hua Yuan
    Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
    Biochemistry 45:12687-94. 2006
  2. pmc Spectroscopic studies of the AppA BLUF domain from Rhodobacter sphaeroides: addressing movement of tryptophan 104 in the signaling state
    Vladimira Dragnea
    Departments of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
    Biochemistry 48:9969-79. 2009

Detail Information

Publications2

  1. pmc Crystal structures of the Synechocystis photoreceptor Slr1694 reveal distinct structural states related to signaling
    Hua Yuan
    Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
    Biochemistry 45:12687-94. 2006
    ..These different tertiary structures may be associated with absorption changes in the blue region of the spectrum...
  2. pmc Spectroscopic studies of the AppA BLUF domain from Rhodobacter sphaeroides: addressing movement of tryptophan 104 in the signaling state
    Vladimira Dragnea
    Departments of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
    Biochemistry 48:9969-79. 2009
    ..These results do not support a model of Trp104 movement as a key output signal...