title: The transmission of nuclear pore complexes to daughter cells requires a cytoplasmic pool of Nsp1.
abstract: Nuclear pore complexes (NPCs) are essential protein assemblies that span the nuclear envelope and establish nuclear-cytoplasmic compartmentalization. We have investigated mechanisms that control NPC number in mother and daughter cells during the asymmetric division of budding yeast. By simultaneously tracking existing NPCs and newly synthesized NPC protomers (nups) through anaphase, we uncovered a pool of the central channel nup Nsp1 that is actively targeted to the bud in association with endoplasmic reticulum. Bud targeting required an intact actin cytoskeleton and the class V myosin, Myo2. Selective inhibition of cytoplasmic Nsp1 or inactivation of Myo2 reduced the inheritance of NPCs in daughter cells, leading to a daughter-specific loss of viability. Our data are consistent with a model in which Nsp1 releases a barrier that otherwise prevents NPC passage through the bud neck. It further supports the finding that NPC inheritance, not de novo NPC assembly, is primarily responsible for controlling NPC number in daughter cells.
authors.affiliation: Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520.
authors.forename: Paolo
authors.initials: P
authors.lastname: Colombi
authors.forename: Brant M
authors.initials: BM
authors.lastname: Webster
authors.forename: Florian
authors.initials: F
authors.lastname: Fröhlich
authors.forename: C Patrick
authors.initials: CP
authors.lastname: Lusk
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000705:Anaphase; D003593:Cytoplasm / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D040941:Heredity; D050296:Microbial Viability; D008856:Microscopy, Fluorescence; D008938:Mitosis; D018995:Myosin Heavy Chains / Q000378:metabolism; D024701:Myosin Type V / Q000378:metabolism; D022022:Nuclear Pore / Q000235:genetics / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014741:Video Recording
chemical_list: C077512:MYO2 protein, S cerevisiae; C062748:NSP1 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D024701:Myosin Type V; D018995:Myosin Heavy Chains