Matthew Chapman's research is aimed at understanding how bacteria integrate into their environment by forming sessile communities called biofilms. To protect themselves, bacteria produce an extracellular matrix that consists of a polysaccharide (in the case of the bacteria that we study, cellulose) and a protein polymer called curli. Curli are structurally and biochemically an amyloid fiber. Amyloid fibers or plaques are insoluble protein aggregations that underlie many neurodegenerative disorders such as Alzheimer's, Huntington's, and the prion diseases. Very little is known about amyloid fiber polymerization. Our lab seeks to understand amyloid formation by studying the biogenesis of an amyloid fiber produced by bacteria called curli. Curli fibers produced by E. coli and other enterobacteriaceae members are important determinants of biofilm formation and are proposed to be virulence factors. Our lab uses a variety of biochemical, microscopic, and genetic techniques to elucidate how E. coli assembles these biologically fascinating fibers. We are also interested in the native function of curli fibers. Curli have been shown to be an integral part of a complex stationary phase developmental pathway in E. coli and Salmonella. This pathway has clear implications for the ability of these bacteria to both survive in nature and to cause disease in humans. Therefore, we are investing the role of curli in coordinating distinct developmental pathways using in vitro and in vivo methods.