Wu Lab

Research Description

The Fission Yeast S. pombe as a Model System to Study Cytokinesis

The fission yeast S. pombe has emerged as a favorite model system for the analysis of cytokinesis. Not only is it genetically tractable and favorable for microscopic analysis, but it also has highly efficient homologous recombination for gene targeting, a small (13.8 Mb) and fully sequenced eukaryotic genome, and perhaps most importantly, it carries out cytokinesis much like animal cells. Cytokinesis begins with the formation of nodes at the cell equator (Figs. 1 and 2). We discovered how cytokinesis nodes condense into a contractile ring by a “search, capture, pull, and release” (SCPR) mechanism (Vavylonis et al., Science 2008). Constriction of the ring is coupled with invagination of the plasma membrane and formation of a trilaminar septum, but the mechanisms coordinating these processes are unknown. Digestion of the primary septum leads to cell separation (Fig. 1). We are studying cytokinesis in S. pombe using complementary genetic, microscopic (confocal, EM, & super-resolution), biochemical, and mathematical approaches. The concepts learned from fission yeast are applicable to the coordination of actomyosin contractile structures, plasma-membrane dynamics, and extracellular matrix remodeling in animal-cell cytokinesis, cell motility, cell morphogenesis, and wound healing since most proteins are conserved.


Fig. 2. Model for cytokinesis node assembly and architecture. Protein distances, stoichiometries
(except Cdc12), and timings of appearance are depicted (Laporte et al., J. Cell Biol. 2011).