The SskA and SrrA Response Regulators Are Implicated in Oxidative Stress Responses of Hyphae and Asexual Spores in the Phosphorelay Signaling Network of Aspergillus nidulans

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Author(s)

    • FURUKAWA Kentaro
    • Laboratory of Enzymology, Graduate School of Agriculture, Tohoku University
    • KANAMARU Kyoko
    • Laboratory of Gene Regulation, Graduate School of Bioagricultural Sciences, Nagoya University
    • KATO Masashi
    • Laboratory of Gene Regulation, Graduate School of Bioagricultural Sciences, Nagoya University
    • ABE Keietsu
    • Laboratory of Enzymology, Graduate School of Agriculture, Tohoku University
    • KOBAYASHI Tetsuo
    • Laboratory of Gene Regulation, Graduate School of Bioagricultural Sciences, Nagoya University
    • YAMASHINO Takafumi
    • Laboratory of Molecular Microbiology, Graduate School of Bioagricultural Sciences, Nagoya University
    • MIZUNO Takeshi
    • Laboratory of Molecular Microbiology, Graduate School of Bioagricultural Sciences, Nagoya University

Abstract

Histidine-to-Aspartate (His-Asp) phosphorelay (or two-component) systems are common signal transduction mechanisms implicated in a wide variety of cellular responses to environmental stimuli in both prokaryotes and eukaryotes. For a model filamentous fungi, <I>Aspergillus nidulans</I>, in this study we first compiled a complete list of His-Asp phosphorelay components, including 15 genes for His-kinase (HK), four genes for response regulator (RR), and only one for histidine-containing phosphotransfer intermediate (HPt). For these RR genes, a set of deletion mutants was constructed so as to create a null allele for each. When examined these mutant strains under various conditions stressful for hyphal growth and asexual spore development, two of them (designated Δ<I>sskA</I> and Δ<I>srrA</I>) showed a marked phenotype of hypersensitivity to oxidative stresses (particularly, to hydrogen peroxide). In this respect, expression of the vegetative-stage specific <I>catB</I> catalase gene was severely impaired in both mutants. Furthermore, conidia from Δ<I>sskA</I> were hypersensitive not only to treatment with H<SUB>2</SUB>O<SUB>2</SUB>, but also to treatment at aberrantly low (4 °C) and high (50 °C) temperatures, resulting in reduced germination efficiency. In this respect, not only the <I>catA</I> catalase gene specific for asexual development, but also a set of genes encoding the enzymes for synthesis of certain stress tolerant compatible solutes, such as trehalose and glycerol, were markedly downregulated in conidia from Δ<I>sskA</I>. These results together are indicative of the physiological importance of the His-Asp phosphorelay signaling network involving the SskA and SrrA response regulators.

Journal

  • Bioscience, Biotechnology, and Biochemistry

    Bioscience, Biotechnology, and Biochemistry 71(4), 1003-1014, 2007-04-23

    Japan Society for Bioscience, Biotechnology, and Agrochemistry

References:  51

Cited by:  10

Codes

  • NII Article ID (NAID)
    10027513743
  • NII NACSIS-CAT ID (NCID)
    AA10824164
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    09168451
  • NDL Article ID
    8715092
  • NDL Source Classification
    ZR7(科学技術--農林水産--農産) // ZR2(科学技術--生物学--生化学) // ZP1(科学技術--化学・化学工業)
  • NDL Call No.
    Z53-G223
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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