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dc.identifier.urihttp://hdl.handle.net/11401/78301
dcterms.abstractMeiotic recombination promotes the formation of crossovers between homologous chromosomes to ensure their proper segregation in Meiosis I. Crossovers are formed by the repair of programmed double strand breaks (DSBs) during meiotic prophase. In budding yeast, the meiotic recombination checkpoint delays meiotic progression until all DSBs have been repaired and is under the control of the meiosis-specific Mek1 kinase. The meiosis-specific transcription factor Ndt80 activates the transcription of hundreds of genes, including those required for prophase exit and the meiotic divisions. Transcription of NDT80 occurs in two stages, mediated first by Ime1 and then by Ndt80 itself. Ime1-transcribed Ndt80 is negatively regulated by the checkpoint, preventing the expression of NDT80 and its downstream targets. Mutated strains which arrest due to unresolved DSBs accumulate inactive Ndt80 in the cytoplasm. Ndt80 contains six putative Mek1 consensus sequences within its DNA-binding domain. While preventing phosphorylation at these sites using alanine substitutions (ndt80-6A) does not affect Ndt80 activity, aspartic acid substitutions (ndt80-6D), which may mimic the negative charge of phosphorylation, make Ndt80 constitutively inactive. Immunoblot analyses showed that ndt80-6D prevents accumulation of Ndt80-dependent gene products, including Ndt80 itself. When the NDT80 gene was put under the control of an inducible promoter, Ndt80-6D protein levels were equivalent to wild-type, although no downstream targets were detected. This result shows that negative charges do not affect Ndt80 protein stability, but instead prevent the accumulation in Ndt80 protein that results from Ndt80-mediated transcription of NDT80. In addition, a fluorescence-based system was developed to allow for the visualization of Ndt80 localization in live cells.
dcterms.available2018-08-13
dcterms.contributorAdvisors: Hollingsworth, Nancy M.; Futcher, Bruce
dcterms.creatorGaglione, Robert
dcterms.date2017
dcterms.dateAccepted2018-07-03T17:22:59Z
dcterms.dateSubmitted2018-07-03T17:22:59Z
dcterms.descriptionDepartment of Biochemistry and Cell Biology
dcterms.descriptionThesis
dcterms.extent73 pages
dcterms.formatapplication/pdf
dcterms.identifierGaglione_grad.sunysb_0771M_13553.pdf
dcterms.identifierhttp://hdl.handle.net/11401/78301
dcterms.issued2017-12-01
dcterms.languageen
dcterms.provenanceSubmitted by Jason Torre (fjason.torre@stonybrook.edu) on 2018-07-03T17:22:59Z No. of bitstreams: 1 Gaglione_grad.sunysb_0771M_13553.pdf: 13969771 bytes, checksum: d860e578e3843f7a6f91b423fe51ff0d (MD5)
dcterms.provenanceMade available in DSpace on 2018-07-03T17:22:59Z (GMT). No. of bitstreams: 1 Gaglione_grad.sunysb_0771M_13553.pdf: 13969771 bytes, checksum: d860e578e3843f7a6f91b423fe51ff0d (MD5) Previous issue date: 2017-12-01
dcterms.publisherStony Brook University
dcterms.subjectMolecular biology
dcterms.titleNegative charges at Mek1 kinase consensus sites downregulate Ndt80 activity during budding yeast meiotic prophase without affecting protein stability
dcterms.typeText


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