Dissertation
The role of the multifunctional RNA binding protein OsTudor-SN in rice storage protein mRNAs transport and localization
Doctor of Philosophy (PhD), Washington State University
01/2017
Handle:
https://hdl.handle.net/2376/111400
Abstract
The packaging of the rice storage proteins, prolamines and glutelins, within the ER lumen and in the storage vacuole, respectively, is facilitated by the localization of their mRNAs to distinct ER subdomains. Specifically, prolamine mRNAs are sorted and translated on the ER membrane (PB-ER) that delimit the prolamine intracisternal inclusion, whereas glutelin mRNAs are localized and translated on adjoining cisternal-ER. A prominent player in mRNA localization in rice is Tudor-SN, which is well documented to play multiple roles in the nucleus and cytoplasm in metazoans. In plants, it is involved in stress tolerance and as a major component of stress granules and P-bodies. Tudor-SN has a modular protein structure consisting of four staphylococcus nuclease (4SN) domains, a Tudor domain and a partial SN domain (Tsn). In this dissertation, we demonstrate the role of the rice OsTudor-SN in regulating mRNA localization and linking its multiple roles in the nucleus and cytoplasm. Biochemical evidence is provided showing that, in addition to intact OsTudor-SN, two natural cleavage products, 4SN and Tsn modules, are present in developing endosperm. The 4SN module binds RNA in vitro and interacts with proteins associated with transcription, plant growth and stress. By contrast, the Tsn module interacts specifically with 8 RBPs. In addition to the distinct biological functions conferred by the modular peptide regions of OsTudor-SN and its influences on storage protein mRNAs localization, we also demonstrate the role of this RBP in storage protein expression, seed development and protein body formation via analysis of OsTudor-SN mutants and a transgenic complemented rice line. In general, OsTudor-SN mutant lines exhibit considerable differences in storage protein accumulation, grain weight and seed appearance. Mutations in both the 4SN and Tsn modules also perturb the packaging of prolamines and glutelins in protein bodies. Genetic complementation transgenic plant exhibits increased grain weight and healthier seed phenotype as compared to the mutant parent. Overall, these results indicate that OsTudor-SN is involved in a myriad of transcriptional and post-transcriptional regulatory steps in the nucleus and cytoplasm, processes linked by it essential role in mRNA transport and localization between these two cellular compartments.
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Details
- Title
- The role of the multifunctional RNA binding protein OsTudor-SN in rice storage protein mRNAs transport and localization
- Creators
- HONG-LI CHOU
- Contributors
- Thomas Okita (Advisor)John Wyrick (Committee Member)Helmut Kirchhoff (Committee Member)Michael Knoblauch (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Program in Molecular Plant Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 156
- Identifiers
- 99900581629601842
- Language
- English
- Resource Type
- Dissertation