Function and assembly of DNA looping, clustering, and microtubule attachment complexes within a eukaryotic kinetochore.
The kinetochore is a complex protein-DNA assembly that provides the mechanical linkage between microtubules and the centromere DNA of each chromosome. Centromere DNA in all eukaryotes is wrapped around a unique nucleosome that contains the histone H3 variant CENP-A (Cse4p in Saccharomyces cerevisiae). Here, we report that the inner kinetochore complex (CBF3) is required for pericentric DNA looping at the Cse4p-containing nucleosome. DNA within the pericentric loop occupies a spatially confined area that is radially displaced from the interpolar central spindle. Microtubule-binding kinetochore complexes are not involved in pericentric DNA looping but are required for the geometric organization of DNA loops around the spindle microtubules in metaphase. Thus, the mitotic segregation apparatus is a composite structure composed of kinetochore and interpolar microtubules, the kinetochore, and organized pericentric DNA loops. The linkage of microtubule-binding to centromere DNA-looping complexes positions the pericentric chromatin loops and stabilizes the dynamic properties of individual kinetochore complexes in mitosis.
Anderson
Marybeth
M
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280, USA.
Haase
Julian
J
Yeh
Elaine
E
Bloom
Kerry
K
D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005057:Eukaryotic Cells / Q000378:metabolism; D036681:Fluorescence Recovery After Photobleaching; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism
C081071:CBF2 protein, S cerevisiae; C092746:CSE4 protein, S cerevisiae; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C120362:MTW1 protein, S cerevisiae; C112472:NDC80 protein, S cerevisiae; C087340:NUF2 protein, S cerevisiae; D009687:Nuclear Proteins; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins