Global regulatory circuits & signal transduction

  • Klemm, Per (Project Manager)
  • Knudsen, Thomas Borch (Project Participant)
  • Christiansen, Gunnar Dan (Project Participant)
  • Brunak, Søren (Project Participant)

    Project Details

    Description

    Bacteria regulate gene transcription in response to a large number of environmental stimuli, not only to "simple signals" such as temperature, pH, osmolarity, and mineral and energy sources but also to more complex signals such as the presence of a suitable alternative niche for example the presence of a host organism (Ninfa, 1996). The expression of a given gene may be modulated by a number of different environmental signals. This is often the case in the regulation of bacterial virulence factors, the regulation of which are often not limited to one easily definable environmental signal. Simultaneous sensing of several signals may serve as a precise "environmental address" indicator to the microbe. Several virulence factors have been characterized which exhibit multiple response profiles to environmental signals. Among these are fimbriae, flagellae, enterobactin and various toxins (Mahan et al., 1996; Mekalanos, 1992; Ninfa, 1996; Ritter et al., 1995). Often the expression of such factors is finely orchestrated by coregulation (crosstalk). A classical example of coregulation is toxin and fimbrial expression in Vibrio cholera (Petersen & Mekalanos, 1988).
    The present proposal is focussed on the role of type 1 fimbriae in relation to global gene regulation and interaction with the environment. The expression of these adhesive surface organelles has been found to respond to a number of environmental signals and is influenced by an array of global regulators. However, interestingly, our recent observations indicate that the fimbriae, or rather the fimbrial adhesin itself, may indeed act as a sensory system and in turn control and modulate the expression of several global regulators which in turn influence numerous cellular parameters including expression of virulence factors.
    StatusFinished
    Effective start/end date01/03/199701/09/2000

    Fingerprint

    Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.