Cell wall function during fission yeast cytokinesis

Abstract

Cytokinesis is the final process of the cell cycle, which gives rise to two independent daughter cells once mitosis is completed. In fungi, as in animal cells, cytokinesis requires the formation of a cleavage furrow that is achieved by constriction of an actomyosin ring and invagination of the plasma membrane. Additionally, since fungal cells have a polysaccharide cell wall outside the plasma membrane, cytokinesis requires the formation of a septum coincident with the membrane ingression. The septum biosynthesis must be strictly coordinated with the deposition of new plasma membrane material and closure of the actomyosin ring, in such a way that no cell lysis occurs during the whole process. Fission yeast Schizosaccharomyces pombe is a unicellular, rod-shaped fungus that has become a popular model organism for the study of actomyosin ring formation and constriction during cell division. We will present recent advances about the reciprocal collaboration between the enzymes responsible for the cell wall synthesis and some components of the actomyosin ring. Our recent studies unveiled the importance of this collaboration in the formation of the cleavage furrow and the construction of a cross-walled septum able to support the high turgor pressure of the cell. In addition, we will discuss the importance of the cell wall in the steady progression of the cleavage furrow.