Cell Biology

Miho Iijima

Miho Iijima

Mechanisms of gradient sensing and chemotaxis are conserved in mammalian leukocytes and Dictyostelium amoebae. Both cells use G protein linked signaling pathways. PH domains specific for PtdIns(3,4)P2 and PtdIns(3,4,5)P3 bind to the membrane at the leading edge of the chemotaxing cell. This suggests that the local production of these phosphoinositides are regulated by PI3Ks and PTEN phosphatases and are a key component of directional sensing. The translocation of specific PH domain containing proteins at the leading edge likely regulates actin polymerization and pseudopud formation.

Andrew Ewald

Andrew Ewald

Background and Summary: Epithelial cells in a tissue live a crowded life connected to, and interacting with, other cell types, the extracellular matrix, and diverse signaling molecules. A fundamental question in biology is: how do the constituent cells of an epithelium collaborate to build and remodel its structure? This seemingly simple question also has great relevance to human disease. Cancer is a disease of disregulated proliferation, but also of disregulated tissue growth and invasion.

Peter Espenshade

Peter Espenshade

Regulation of Sterol Homeostasis Elevated serum cholesterol is a primary risk factor for heart disease. A negative feedback mechanism prevents excessive cellular cholesterol accumulation by regulating SREBP, a membrane-bound transcription factor that activates genes required for cholesterol biosynthesis and uptake of cholesterol-rich lipoproteins. We use the genetics of fission yeast as a discovery tool to identify new components of this sterol-sensing pathway in mammalian cells.

Peter Devreotes

Peter Devreotes

Chemotaxis plays a key role in immune response, wound healing, angiogenesis, and embryogenesis as well as mediating cancer metastasis. Research in Dictyostelium discoideum has shown that chemoattractants are sensed by GPCRs and rapidly trigger a complex network of signaling pathways. Our strategy is to use the genetics of Dictyostelium to discover mechanisms by which cells sense chemical gradients and to apply this information to other eukaryotic cells such as human neutrophils and epithelial cells.

Pages