Disentangling information flow in the Ras-cAMP signaling network

  1. Gregory W. Carter1,4,
  2. Steffen Rupp2,
  3. Gerald R. Fink3, and
  4. Timothy Galitski1
  1. 1 Institute for Systems Biology, Seattle, Washington 98103, USA;
  2. 2 Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart, Germany;
  3. 3 Whitehead Institute, Cambridge, Massachusetts 02142, USA

Abstract

The perturbation of signal-transduction molecules elicits genomic-expression effects that are typically neither restricted to a small set of genes nor uniform. Instead there are broad, varied, and complex changes in expression across the genome. These observations suggest that signal transduction is not mediated by isolated pathways of information flow to distinct groups of genes in the genome. Rather, multiple entangled paths of information flow influence overlapping sets of genes. Using the Ras-cAMP pathway in Saccharomyces cerevisiae as a model system, we perturbed key pathway elements and collected genomic-expression data. Singular value decomposition was applied to separate the genome-wide transcriptional response into weighted expression components exhibited by overlapping groups of genes. Molecular interaction data were integrated to connect gene groups to perturbed signaling elements. The resulting series of linked subnetworks maps multiple putative pathways of information flow through a dense signaling network, and provides a set of testable hypotheses for complex gene-expression effects across the genome.

Footnotes

  • 4

    4 Corresponding author.

    4 E-mail gcarter{at}systemsbiology.org; fax (206) 732-1299.

  • [Supplemental material is available online at www.genome.org. Genomic-expression data have been deposited in the Gene Expression Omnibus database under accession no. GSE2927.]

  • Article published online ahead of print. Article and publication date are at http://www.genome.org/cgi/doi/10.1101/gr.4473506

    • Received July 21, 2005.
    • Accepted January 17, 2006.
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