The Devreotes Laboratory is engaged in genetic analysis of chemotaxis in eukaryotic cells. Our long-term goal is a complete description of the network controlling chemotactic behavior. We are analyzing combinations of deficiencies to understand interactions among network components and carrying out additional genetic screens to identify new pathways involved in chemotaxis. A comprehensive understanding of this fascinating process should lead to control of pathological conditions such as inflammation and cancer metastasis.

Complexity in signaling networks is often derived from co-opting one set of molecules for multiple operations. Understanding how cells achieve such sophisticated processing using a finite set of molecules within a confined space--what we call the ""signaling paradox""--is critical to biology and engineering as well as the emerging field of synthetic biology. In the Inoue Lab, we have recently developed a series of chemical-molecular tools that allow for inducible, quick-onset and specific perturbation of various signaling molecules. Using this novel technique in conjunction with fluorescence imaging, microfabricated devices, quantitative analysis and computational modeling, we are dissecting intricate signaling networks. In particular, we investigate positive-feedback mechanisms underlying the initiation of neutrophil chemotaxis (known as symmetry breaking), as well as spatio-temporally compartmentalized signaling of Ras and membrane lipids such as phosphoinositides. In parallel, we also try to understand how cell morphology affects biochemical pathways inside cells. Ultimately, we will generate completely orthogonal machinery in cells to achieve existing, as well as novel, cellular functions. Our synthetic, multidisciplinary approach will elucidate the signaling paradox created by nature.

The Miho Iijima Laboratory works to make a further connection between cells' signaling events and directional movement. Our researchers have identified 17 new PH domain-containing proteins in addition to 10 previously known genes in the Dictyostelium cDNA and genome database. Five of these genes contain both the Dbl and the PH domains, suggesting these proteins are involved in actin polymerization. A PTEN homologue has also been identified in Dictyostelium that is highly conserved with the human gene. We are disrupting all of these genes and studying their roles in chemotaxis.

Investigators in the Pablo Iglesias Lab use analytic tools from control systems and dynamical systems to study cell biology, including biological signal transduction pathways. Our research interests include the ways cells interpret directional cues to guide their motion, regulatory mechanisms that control cell division, and the sensing and actuation that enable cells to maintain lipid homeostasis.