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dc.contributor.advisorMoazed, Danesh
dc.contributor.authorMorris, Corey
dc.date.accessioned2013-02-25T14:54:05Z
dc.date.issued2013-02-25
dc.date.submitted2011
dc.identifier.citationMorris, Corey. 2011. A Role for Nucleoporin Nup211 in Centromere Structure and Function in Schizosaccharomyces Pombe. Doctoral dissertation, Harvard University.en_US
dc.identifier.otherhttp://dissertations.umi.com/gsas.harvard:10053en
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:10336919
dc.description.abstractEukaryotic centromeres are the region upon which kinetochores assemble, directing attachment of spindle microtubules and faithful segregation of chromosomes during mitosis and meiosis. Except for a transient disruption in mitosis when chromosomes are segregated, centromeres of fission yeast Schizosaccharomyces pombe remain closely associated with the nuclear periphery. Similar to multicellular eukaryotic centromeres, they also maintain unique chromatin architecture, with a central core defined by the presence of the conserved centromeric histone H3 variant CENP-A, designated Cnp1 in S. pombe, that is flanked by histone H3 containing heterochromatin. While much progress has been made in understanding chromatin-associated factors important for proper centromere function, many questions remain. In order to gain a better understanding of the factors involved in centromeric chromatin structure, we affinity purified and defined by mass spectrometry interactions among select proteins that had been implicated in proper Cnp1 localization and centromere function. These biochemical purifications revealed several proteins that may be involved in Cnp1 localization. Purification and analyses of Cnp1 also led us to the identification of the Mlp1/Tpr nucleoporin homolog Nup211. We have found that Nup211 interacts with components of the inner nuclear basket of the nuclear pore, and co-purifies with centromeric chromatin proteins. Cells lacking Nup211 have substantial chromosome segregation defects, as observed by synthetic growth assay, flow cytometric analysis, and fluorescent microscopy. A series of immunoprecipitation experiments have revealed that Nup211 associates with centromeric DNA, and that, surprisingly, cells lacking Nup211 have increased histone H3 lysine 9 methylation, a marker of heterochromatin, and a reduction in Cnp1 levels at the central core. Moreover, cells lacking Nup211 have decreased transcription at centromeric loci, disruption of the stereotypical nucleosome structure found at the central core of S. pombe, and show striking changes in the distribution of heterochromatic foci in the nucleus. By demonstrating that Nup211 is essential for the maintenance of normal central core chromatin state, these studies have shed light on a novel role for Nup211 in proper centromere structure and function in S. pombe, and suggest that Nup211 may play a role in preventing the invasion of flanking pericentric heterochromatin into the central core of centromeres.en_US
dc.language.isoen_USen_US
dash.licenseMETA_ONLY
dc.subjectCENP-Aen_US
dc.subjectcentromereen_US
dc.subjectchromatinen_US
dc.subjectfission yeasten_US
dc.subjectNup211en_US
dc.subjectSchizosaccharomyces pombeen_US
dc.subjectcellular biologyen_US
dc.subjectbiochemistryen_US
dc.subjectgeneticsen_US
dc.titleA Role for Nucleoporin Nup211 in Centromere Structure and Function in Schizosaccharomyces Pombeen_US
dc.typeThesis or Dissertationen_US
dash.embargo.until10000-01-01
thesis.degree.date2011en_US
thesis.degree.disciplineCell and Developmental Biologyen_US
thesis.degree.grantorHarvard Universityen_US
thesis.degree.leveldoctoralen_US
thesis.degree.namePh.D.en_US
dc.contributor.committeeMemberAhmad, Kamien_US
dc.contributor.committeeMemberBuratowski, Stephenen_US
dc.contributor.committeeMemberAnnunziato, Anthonyen_US


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