Cell division is a fundamental cellular process about which is still poorly understood. Cytokinesis involves an actin-based contractile ring that squeezes the cell into two. We are interested in the questions of how the ring is assembled and how cell division plane are placed in the cell. In animal cells, microtubules of the mitotic spindle seem to instruct the cell where to divide. In S. pombe, the cell division site appears to be determined by the position of the medial nucleus.

Genetic screens for cytokinesis-defective mutants have identified many factors required for assembly of this contractile ring and its placement. Remarkably, many of these gene products are conserved from yeast to mammals. To learn about ring assembly and positioning, our lab has focused efforts on understanding the formin cdc12p and the PCH protein cdc15p, which are involved in ring construction, and mid1p, a putative signal protein that positions the cell division plane.

Current projects in the lab include: looking at characterizing protein complexes involved in contractile actin ring assembly, targeting of contractile ring components to the middle of the cell, role of the nucleus and mid1 in ring placement, formation of lipid raft domains at the cell division site, and mechanism of ring contraction.