title: Cytokinetic nodes in fission yeast arise from two distinct types of nodes that merge during interphase.
abstract: We investigated the assembly of cortical nodes that generate the cytokinetic contractile ring in fission yeast. Observations of cells expressing fluorescent fusion proteins revealed two types of interphase nodes. Type 1 nodes containing kinase Cdr1p, kinase Cdr2p, and anillin Mid1p form in the cortex around the nucleus early in G2. Type 2 nodes with protein Blt1p, guanosine triphosphate exchange factor Gef2p, and kinesin Klp8p emerge from contractile ring remnants. Quantitative measurements and computer simulations showed that these two types of nodes come together by a diffuse-and-capture mechanism: type 2 nodes diffuse to the equator and are captured by stationary type 1 nodes. During mitosis, cytokinetic nodes with Mid1p and all of the type 2 node markers incorporate into the contractile ring, whereas type 1 nodes with Cdr1p and Cdr2p follow the separating nuclei before dispersing into the cytoplasm, dependent on septation initiation network signaling. The two types of interphase nodes follow parallel branches of the pathway to prepare nodes for cytokinesis.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, 2 Department of Molecular Biophysics and Biochemistry, 3 Nanobiology Institute, and 4 Department of Cell Biology, Yale University, New Haven, CT 06520.
authors.forename: Matthew
authors.initials: M
authors.lastname: Akamatsu
authors.forename: Julien
authors.initials: J
authors.lastname: Berro
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Pu
authors.forename: Irene R
authors.initials: IR
authors.lastname: Tebbs
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Pollard
mesh_terms: D003198:Computer Simulation; D048749:Cytokinesis; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D007399:Interphase; D016547:Kinesins / Q000378:metabolism; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008938:Mitosis; D008954:Models, Biological; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012568:Schizosaccharomyces / Q000502:physiology* / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D059008:Time-Lapse Imaging
chemical_list: C582271:Gef2 protein, S pombe; D020662:Guanine Nucleotide Exchange Factors; C489694:Mid1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D011494:Protein Kinases; C113816:Sid2 protein, S pombe; C080364:cdr1 protein, S pombe; D011505:Protein-Tyrosine Kinases; C542567:Cdr2 protein, S pombe; D017346:Protein Serine-Threonine Kinases; D016547:Kinesins