title: Extracellular cell wall β(1,3)glucan is required to couple septation to actomyosin ring contraction.
abstract: Cytokinesis has been extensively studied in different models, but the role of the extracellular cell wall is less understood. Here we studied this process in fission yeast. The essential protein Bgs4 synthesizes the main cell wall β(1,3)glucan. We show that Bgs4-derived β(1,3)glucan is required for correct and stable actomyosin ring positioning in the cell middle, before the start of septum formation and anchorage to the cell wall. Consequently, β(1,3)glucan loss generated ring sliding, oblique positioned rings and septa, misdirected septum synthesis indicative of relaxed rings, and uncoupling between a fast ring and membrane ingression and slow septum synthesis, suggesting that cytokinesis can progress with defective septum pushing and/or ring pulling forces. Moreover, Bgs4-derived β(1,3)glucan is essential for secondary septum formation and correct primary septum completion. Therefore, our results show that extracellular β(1,3)glucan is required for cytokinesis to connect the cell wall with the plasma membrane and for contractile ring function, as proposed for the equivalent extracellular matrix in animal cells.
authors.affiliation: Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, 37007 Salamanca, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Muñoz
authors.forename: Juan Carlos G
authors.initials: JC
authors.lastname: Cortés
authors.forename: Matthias
authors.initials: M
authors.lastname: Sipiczki
authors.forename: Mariona
authors.initials: M
authors.lastname: Ramos
authors.forename: José Angel
authors.initials: JA
authors.lastname: Clemente-Ramos
authors.forename: M Belén
authors.initials: MB
authors.lastname: Moreno
authors.forename: Ivone M
authors.initials: IM
authors.lastname: Martins
authors.forename: Pilar
authors.initials: P
authors.lastname: Pérez
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Ribas
mesh_terms: D000205:Actomyosin / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism*; D048749:Cytokinesis; D005838:Genotype; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D050296:Microbial Viability; D008856:Microscopy, Fluorescence; D010641:Phenotype; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D059008:Time-Lapse Imaging; D014741:Video Recording; D047071:beta-Glucans / Q000378:metabolism*
chemical_list: D029702:Schizosaccharomyces pombe Proteins; D047071:beta-Glucans; D000205:Actomyosin; C033363:beta-1,3-glucan; D005964:Glucosyltransferases; C511266:Bgs4 protein, S pombe