RHO GTPases in the control of cell morphology, cell polarity, and actin localization in fission yeast

The fission yeast Schizosaccharomyces pombe undergoes morphogenetic changes during both vegetative and sexual cell cycles that require asymmetric cell growth and actin cytoskeleton reorganisations. Different complex signal tr ansduction pathways participate in S. pombe morphogenesis. The Rho family o f GTPases are present in all eukaryotic cells, from yeast to mammals, and t heir role as key regulators in the signalling pathways that control actin o rganisation and morphogenetic processes is well known. In this review, we w ill briefly summarize the role of the Rho GTPases in the establishment and maintenance of cell polarity and growth of S. pombe. As in other fungi, S. pombe morphogenesis is closely related to cell wall biosynthesis, and Rho G TPases are critical modulators of this process. They provide the coordinate d regulation of cell wall biosynthetic enzymes and actin organisation requi red to maintain cell integrity and polarised growth. (C) 1999 Wiley-Liss, I nc.