Molecular understanding of cell morphogenesis and cytokinesis in the fission yeast schizosaccharomyces pombe

Abstract

The fission yeast Schizosaccharomyces pombe cell grows in a polarized manner by tip elongation and divides by fission to generate two daughter cells of equal size. In recent years, many mutants defective in polarized growth and cell division have been isolated; however, the underlying molecular mechanisms remain not fully understood. In the first part of this study, I have identified a novel protein Pal1p and its interacting partner Sla2p and shown that they are required for the maintenance of cylindrical cell morphology. By monitoring the growth pattern in cells with various cell shapes, I have further elucidated that the cylindrical cell shape is important for the coordination between the mitotic spindle and the actomyosin ring. In the second part, I have identified a Paxillin-related protein Pxl1p and found it is a novel component of the actomyosin ring. Further studies suggest that Pxl1p plays a significant role in modulating the function of type II myosin and Rng2p during cytokinesis. In addition, Pxl1p also ensures the integrity of the actomyosin ring during contraction.