Our laboratory is interested in the structural biochemistry
of two systems - the cytoskeleton and the extracellular
matrix. Our work on cytoskeleton is now focused on
FtsZ, the major bacterial cytoskeletal protein that
powers division in all bacteria. FtsZ is a homolog
of tubulin, so what we learn has implications for
the eukaryotic cytoskeleton. We are trying to determine
how FtsZ assembles into the contractile ring and generates
the force to divide bacteria. We are using in vitro
assembly studies and site directed mutagenesis. Recently
we have developed fluorescence techniques, which demonstrate
extremely fast assembly dynamics in vitro and in vivo.
We are now working to develop single molecule (TIRF)
fluorescence microscopy to follow the assembly dynamics
of single FtsZ protofilaments. Our ultimate goal is
to be able to recreate a contractile band based on
FtsZ.
Our work on the extracellular matrix focuses primarily
on fibronectin. We have made a GFP-fibronectin construct
that permits us to follow the assembly of the fibronectin
matrix in real time. We have found that the matrix
fibrils are highly elastic, and are now seeking the
mechanism for stretching. Again, fluorescence techniques
are proving powerful tools to probe stretching at
the molecular level.
