title: Ingression Progression Complexes Control Extracellular Matrix Remodelling during Cytokinesis in Budding Yeast.
abstract: Eukaryotic cells must coordinate contraction of the actomyosin ring at the division site together with ingression of the plasma membrane and remodelling of the extracellular matrix (ECM) to support cytokinesis, but the underlying mechanisms are still poorly understood. In eukaryotes, glycosyltransferases that synthesise ECM polysaccharides are emerging as key factors during cytokinesis. The budding yeast chitin synthase Chs2 makes the primary septum, a special layer of the ECM, which is an essential process during cell division. Here we isolated a group of actomyosin ring components that form complexes together with Chs2 at the cleavage site at the end of the cell cycle, which we named 'ingression progression complexes' (IPCs). In addition to type II myosin, the IQGAP protein Iqg1 and Chs2, IPCs contain the F-BAR protein Hof1, and the cytokinesis regulators Inn1 and Cyk3. We describe the molecular mechanism by which chitin synthase is activated by direct association of the C2 domain of Inn1, and the transglutaminase-like domain of Cyk3, with the catalytic domain of Chs2. We used an experimental system to find a previously unanticipated role for the C-terminus of Inn1 in preventing the untimely activation of Chs2 at the cleavage site until Cyk3 releases the block on Chs2 activity during late mitosis. These findings support a model for the co-ordinated regulation of cell division in budding yeast, in which IPCs play a central role.
authors.affiliation: Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.|Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Foltman
authors.affiliation: Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.|Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain.
authors.forename: Iago
authors.initials: I
authors.lastname: Molist
authors.affiliation: Instituto de Biología Funcional y Genómica, Departamento de Microbiología y Genética, CSIC, Universidad de Salamanca, Salamanca, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Arcones
authors.affiliation: Instituto de Biología Funcional y Genómica, Departamento de Microbiología y Genética, CSIC, Universidad de Salamanca, Salamanca, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sacristan
authors.affiliation: Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.|Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain.
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Filali-Mouncef
authors.affiliation: Instituto de Biología Funcional y Genómica, Departamento de Microbiología y Genética, CSIC, Universidad de Salamanca, Salamanca, Spain.
authors.forename: Cesar
authors.initials: C
authors.lastname: Roncero
authors.affiliation: Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.|Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Sanchez-Diaz
mesh_terms: D000205:Actomyosin / Q000378:metabolism; D055162:Biocatalysis; D020134:Catalytic Domain; D002455:Cell Division; D002686:Chitin / Q000096:biosynthesis; D048749:Cytokinesis; D005109:Extracellular Matrix / Q000378:metabolism*; D008954:Models, Biological; D011485:Protein Binding; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism; D004718:Saccharomycetales / Q000166:cytology* / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D002686:Chitin; D000205:Actomyosin