Nup132 modulates meiotic spindle attachment in fission yeast by regulating kinetochore assembly.
During meiosis, the kinetochore undergoes substantial reorganization to establish monopolar spindle attachment. In the fission yeast Schizosaccharomyces pombe, the KNL1-Spc7-Mis12-Nuf2 (KMN) complex, which constitutes the outer kinetochore, is disassembled during meiotic prophase and is reassembled before meiosis I. Here, we show that the nucleoporin Nup132 is required for timely assembly of the KMN proteins: In the absence of Nup132, Mis12 and Spc7 are precociously assembled at the centromeres during meiotic prophase. In contrast, Nuf2 shows timely dissociation and reappearance at the meiotic centromeres. We further demonstrate that depletion of Nup132 activates the spindle assembly checkpoint in meiosis I, possibly because of the increased incidence of erroneous spindle attachment at sister chromatids. These results suggest that precocious assembly of the kinetochores leads to the meiosis I defects observed in the nup132-disrupted mutant. Thus, we propose that Nup132 plays an important role in establishing monopolar spindle attachment at meiosis I through outer kinetochore reorganization at meiotic prophase.
Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan.
Hui-Ju
HJ
Yang
Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan.
Haruhiko
H
Asakawa
Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Iwaoka-cho, Nishi-ku, Kobe 651-2492, Japan.
Tokuko
T
Haraguchi
Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Iwaoka-cho, Nishi-ku, Kobe 651-2492, Japan hiraoka@fbs.osaka-u.ac.jp.
Yasushi
Y
Hiraoka
D018797:Cell Cycle Proteins / Q000378:metabolism; D002842:Chromatids / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D020090:Chromosome Segregation / Q000235:genetics; D017353:Gene Deletion; D018386:Kinetochores / Q000378:metabolism*; D008540:Meiosis / Q000235:genetics; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism*
D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D008869:Microtubule-Associated Proteins; D046912:Multiprotein Complexes; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; C000604969:Nup132 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; C500242:Spc7 protein, S pombe; C492315:mis12 protein, S pombe; C490196:nuf2 protein, S pombe; C495594:Bub1 protein, S pombe; D017346:Protein Serine-Threonine Kinases