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dc.identifier.urihttp://hdl.handle.net/11401/76587
dc.description.sponsorshipThis work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.en_US
dc.formatMonograph
dc.format.mediumElectronic Resourceen_US
dc.language.isoen_US
dc.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.
dc.typeDissertation
dcterms.abstractAbstract The local translation of trafficked mRNAs temporally and spatially regulates protein expression. In neurons, mRNAs are trafficked to both axons and dendrites and the local translation of these mRNAs is important for axon guidance as well as synaptic plasticity. The active trafficking of mRNAs involves the interaction between cis¬¬-acting localization elements, known as `zipcodes,' and trans-acting factors, including RNA-binding proteins. However, the exact molecular mechanism of mRNA localization in the mammalian nervous system remains unknown. To better understand this process, the zipcode element of  -actin (Actb) mRNA was used to identify putative  -actin zipcode binding proteins from the rodent brain (bZBPs). Hnrnpab was confirmed as a bZBP and was found to have an unexpected isoform dependent specificity. The larger isoform, Hnrnpab1, is specific for Actb mRNA and the zipcode localization element. The alternatively spliced isoform, Hnrnpab2, interacts with the zipcode element and the 5' UTR of Actb mRNA as well as  -actin (Actg) mRNA. Analysis using a novel fluorescent in situ hybridization method demonstrated a decrease in Actb mRNA in the periphery of cells in the absence of Hnrnpab. This effect can be rescued only with the Hnrnpab1 isoform, suggesting a distinct function in Actb mRNA localization. Mice lacking Hnrnpab show a number of changes in protein expression which suggest a role in nervous system development and glutamate signaling. Hnrnpab-/- neural stem and progenitor cells undergo altered differentiation patterns in culture, and mature Hnrnpab-/- neurons demonstrate increased sensitivity to glutamate-induced excitotoxicity. These studies represent an important step in understanding the underlying molecular mechanism of mRNA trafficking by identifying several putative localization factors using the localization element of Actb mRNA and establishing Hnrnpab1 as a zipcode binding protein, which mediates Actb mRNA localization. They also explore the role of Hnrnpab in the nervous system and provide evidence for isoform dependent functions.
dcterms.abstractAbstract The local translation of trafficked mRNAs temporally and spatially regulates protein expression. In neurons, mRNAs are trafficked to both axons and dendrites and the local translation of these mRNAs is important for axon guidance as well as synaptic plasticity. The active trafficking of mRNAs involves the interaction between cis¬¬-acting localization elements, known as `zipcodes,' and trans-acting factors, including RNA-binding proteins. However, the exact molecular mechanism of mRNA localization in the mammalian nervous system remains unknown. To better understand this process, the zipcode element of  -actin (Actb) mRNA was used to identify putative  -actin zipcode binding proteins from the rodent brain (bZBPs). Hnrnpab was confirmed as a bZBP and was found to have an unexpected isoform dependent specificity. The larger isoform, Hnrnpab1, is specific for Actb mRNA and the zipcode localization element. The alternatively spliced isoform, Hnrnpab2, interacts with the zipcode element and the 5' UTR of Actb mRNA as well as  -actin (Actg) mRNA. Analysis using a novel fluorescent in situ hybridization method demonstrated a decrease in Actb mRNA in the periphery of cells in the absence of Hnrnpab. This effect can be rescued only with the Hnrnpab1 isoform, suggesting a distinct function in Actb mRNA localization. Mice lacking Hnrnpab show a number of changes in protein expression which suggest a role in nervous system development and glutamate signaling. Hnrnpab-/- neural stem and progenitor cells undergo altered differentiation patterns in culture, and mature Hnrnpab-/- neurons demonstrate increased sensitivity to glutamate-induced excitotoxicity. These studies represent an important step in understanding the underlying molecular mechanism of mRNA trafficking by identifying several putative localization factors using the localization element of Actb mRNA and establishing Hnrnpab1 as a zipcode binding protein, which mediates Actb mRNA localization. They also explore the role of Hnrnpab in the nervous system and provide evidence for isoform dependent functions.
dcterms.available2017-09-20T16:50:42Z
dcterms.contributorHalegoua, Simonen_US
dcterms.contributorCzaplinski, Kevinen_US
dcterms.contributorTwiss, Jeffery.en_US
dcterms.contributorTalmage, Daviden_US
dcterms.creatorSinnamon, John Richard
dcterms.dateAccepted2017-09-20T16:50:42Z
dcterms.dateSubmitted2017-09-20T16:50:42Z
dcterms.descriptionDepartment of Neuroscience.en_US
dcterms.extent135 pg.en_US
dcterms.formatApplication/PDFen_US
dcterms.formatMonograph
dcterms.identifierhttp://hdl.handle.net/11401/76587
dcterms.issued2015-08-01
dcterms.languageen_US
dcterms.provenanceMade available in DSpace on 2017-09-20T16:50:42Z (GMT). No. of bitstreams: 1 Sinnamon_grad.sunysb_0771E_11622.pdf: 7411037 bytes, checksum: cab2007faa22bd8082185e3515d41e8b (MD5) Previous issue date: 2013en
dcterms.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.
dcterms.subjectBiology
dcterms.titleIdentification and characterization of Actb mRNA localization factors in the nervous system
dcterms.typeDissertation


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