Systems Approach Depicts How Halobacterium Responds to Metal Fluxes
Global transcriptional fluxes and other system-wide analyses of Halobacterium NRC-1 provide a holistic picture of how this archaeon responds to changes of six transition metals, paving the way to devel- opment of a systems-scale model, according to Nitin Baliga of the Institute for Systems Biology in Seattle, Wash., and collaborators. They studied messenger RNA changes in some 66 steady-state and time- series microarray experiments, while also monitoring 2,187 functional proteins and about 6,000 protein-DNA interactions in the wild type and in 17 gene knockout strains of this microorganism. Their analysis led the researchers to develop a systems-level model, indicating that all or some of at least 13 metal-binding regulators “directly sense changes in metal ion concentrations to differentially regulate up to 43 transcrip- tion regulators and five GTFs [general transcription factors].” Further- more, they add, “The complex interplay among these transcription factors and regulators elicits a concerted response to minimize metal toxicity and oxidative stress, repair damaged proteins and DNA, and modulate cell physiology, including processes requiring metallo- enzymes.” Details appear in the July issue of Genome Research and are available online (DOI: 10.1101/gr.5189606).