title: The Cell Biology of Fission Yeast Septation.
abstract: In animal cells, cytokinesis requires the formation of a cleavage furrow that divides the cell into two daughter cells. Furrow formation is achieved by constriction of an actomyosin ring that invaginates the plasma membrane. However, fungal cells contain a rigid extracellular cell wall surrounding the plasma membrane; thus, fungal cytokinesis also requires the formation of a special septum wall structure between the dividing cells. The septum biosynthesis must be strictly coordinated with the deposition of new plasma membrane material and actomyosin ring closure and must occur in such a way that no breach in the cell wall occurs at any time. Because of the high turgor pressure in the fungal cell, even a minor local defect might lead to cell lysis and death. Here we review our knowledge of the septum structure in the fission yeast Schizosaccharomyces pombe and of the recent advances in our understanding of the relationship between septum biosynthesis and actomyosin ring constriction and how the two collaborate to build a cross-walled septum able to support the high turgor pressure of the cell. In addition, we discuss the importance of the septum biosynthesis for the steady ingression of the cleavage furrow.
authors.affiliation: Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain cortes@usal.es.
authors.forename: Juan C
authors.initials: JC
authors.lastname: García Cortés
authors.affiliation: Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
authors.forename: Mariona
authors.initials: M
authors.lastname: Ramos
authors.affiliation: Laboratory of Electron Microscopy, Faculty of Science, Japan Women's University, Tokyo, and NPO: Integrated Imaging Research Support, Tokyo, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Osumi
authors.affiliation: Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Pérez
authors.affiliation: Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Ribas
mesh_terms: D000595:Amino Acid Sequence; D002473:Cell Wall / Q000378:metabolism* / Q000648:ultrastructure; D048749:Cytokinesis / Q000502:physiology*; D062610:Fungal Polysaccharides / Q000378:metabolism*; D005964:Glucosyltransferases / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000254:growth & development*
chemical_list: D062610:Fungal Polysaccharides; D005964:Glucosyltransferases; C020570:1,3-beta-glucan synthase