title: Assembly and architecture of precursor nodes during fission yeast cytokinesis.
abstract: The contractile ring is essential for cytokinesis in most fungal and animal cells. In fission yeast, cytokinesis nodes are precursors of the contractile ring and mark the future cleavage site. However, their assembly and architecture have not been well described. We found that nodes are assembled stoichiometrically in a hierarchical order with two modules linked by the positional marker anillin Mid1. Mid1 first recruits Cdc4 and IQGAP Rng2 to form module I. Rng2 subsequently recruits the myosin-II subunits Myo2 and Rlc1. Mid1 then independently recruits the F-BAR protein Cdc15 to form module II. Mid1, Rng2, Cdc4, and Cdc15 are stable node components that accumulate close to the plasma membrane. Both modules recruit the formin Cdc12 to nucleate actin filaments. Myo2 heads point into the cell interior, where they efficiently capture actin filaments to condense nodes into the contractile ring. Collectively, our work characterizing the assembly and architecture of precursor nodes defines important steps and molecular players for contractile ring assembly.
authors.affiliation: Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Damien
authors.initials: D
authors.lastname: Laporte
authors.forename: Valerie C
authors.initials: VC
authors.lastname: Coffman
authors.forename: I-Ju
authors.initials: IJ
authors.lastname: Lee
authors.forename: Jian-Qiu
authors.initials: JQ
authors.lastname: Wu
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D003285:Contractile Proteins / Q000378:metabolism; D048749:Cytokinesis / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D024462:Myosin Type II / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology* / Q000502:physiology; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: C082279:CDC15 protein; D018797:Cell Cycle Proteins; D003285:Contractile Proteins; D003598:Cytoskeletal Proteins; D020690:GTPase-Activating Proteins; C489694:Mid1 protein, S pombe; D011993:Recombinant Fusion Proteins; C114172:Rng2 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; C095886:anillin; C513274:cdc4 protein, S pombe; C490463:rlc1 protein, S pombe; D019204:GTP-Binding Proteins; D024462:Myosin Type II