1. Genetics and Genomics
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Differing isoforms of the cobalamin binding photoreceptor AerR oppositely regulate photosystem expression

  1. Haruki Yamamoto
  2. Mingxu Fang
  3. Vladimira Dragnia
  4. Carl E Bauer  Is a corresponding author
  1. Indiana University, United States
Research Article
  • Cited 4
  • Views 684
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Cite this article as: eLife 2018;7:e39028 doi: 10.7554/eLife.39028

Abstract

Phototrophic microorganisms adjust photosystem synthesis in response to changes in light intensity and wavelength. A variety of different photoreceptors regulate this process. Purple photosynthetic bacteria synthesize a novel photoreceptor AerR that uses cobalamin (B12) as a blue-light absorbing chromophore to control photosystem synthesis. AerR directly interacts with the redox responding transcription factor CrtJ, affecting CrtJ's interaction with photosystem promoters. In this study, we show that AerR is translated as two isoforms that differ by 41 amino acids at the amino terminus. The ratio of these isoforms was affected by light and cell growth phase with the long variant predominating during photosynthetic exponential growth and the short variant predominating in dark conditions and/or stationary phase. Pigmentation and transcriptomic analyses show that the short AerR variant represses, while long variant activates, photosynthesis genes. The long form of AerR also activates many genes involved in cellular metabolism and motility.

Article and author information

Author details

  1. Haruki Yamamoto

    Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Mingxu Fang

    Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1595-8046
  3. Vladimira Dragnia

    Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Carl E Bauer

    Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, United States
    For correspondence
    bauer@indiana.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1432-0756

Funding

National Institutes of Health (GM040941)

  • Carl E Bauer

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Gisela Storz, National Institute of Child Health and Human Development, United States

Publication history

  1. Received: June 8, 2018
  2. Accepted: October 2, 2018
  3. Accepted Manuscript published: October 3, 2018 (version 1)
  4. Version of Record published: October 23, 2018 (version 2)

Copyright

© 2018, Yamamoto et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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