title: The alpha-glucanase Agn1p is required for cell separation in Schizosaccharomyces pombe.
abstract: BACKGROUND
  In animal cells, cytokinesis occurs by constriction of an actomyosin ring. In fission yeast, ring constriction is followed by deposition of a multilayered division septum that must be cleaved to release the two daughter cells. Although many studies have focused on the actomyosin ring and septum assembly, little is known about the later steps involving the cleavage of the cell wall.
  
  
  RESULTS
  We identified a novel gene in Schizosaccharomyces pombe, namely the agn1(+) gene that has homology to fungal 1,3-alpha-glucanases (mutanases). Disruption of the agn1(+) gene is not lethal to the cells, but does interfere with their separation, whereas overexpression of Agn1p is toxic and causes cell lysis. Agn1p levels reach a peak during septation and the protein localizes to the septum region before cell separation. Moreover, agn1(+) is responsible for the 1,3-alpha-glucanase activity, which shows a maximum at the end of septation.
  
  
  CONCLUSIONS
  Our results clearly suggest the existence of a relationship between agn1(+), 1,3-alpha-glucanase activity and the completion of septation in S. pombe. Agn1p could be involved in the cleavage of the cylinder of the old wall that surrounds the primary septum, a region rich in alpha-glucans.
authors.affiliation: Instituto de Microbiología Bioquímica, CSIC/Universidad de Salamanca and Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, 37007 Salamanca, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: García
authors.forename: David
authors.initials: D
authors.lastname: Jiménez
authors.forename: Victoria
authors.initials: V
authors.lastname: Martín
authors.forename: Angel
authors.initials: A
authors.lastname: Durán
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Sánchez
mesh_terms: D002455:Cell Division / Q000235:genetics*; D048749:Cytokinesis; D006026:Glycoside Hydrolases / Q000378:metabolism*; D008857:Microscopy, Interference; D009154:Mutation; D010641:Phenotype; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000502:physiology
chemical_list: D029702:Schizosaccharomyces pombe Proteins; D006026:Glycoside Hydrolases; C021780:exo-1,3-alpha-glucanase