1
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Assmann SM, Chou HL, Bevilacqua PC. Rock, scissors, paper: How RNA structure informs function. Plant Cell 2023; 35:1671-1707. [PMID: 36747354 DOI: 10.1093/plcell/koad026] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/05/2023] [Accepted: 01/30/2023] [Indexed: 05/30/2023]
Abstract
RNA can fold back on itself to adopt a wide range of structures. These range from relatively simple hairpins to intricate 3D folds and can be accompanied by regulatory interactions with both metabolites and macromolecules. The last 50 yr have witnessed elucidation of an astonishing array of RNA structures including transfer RNAs, ribozymes, riboswitches, the ribosome, the spliceosome, and most recently entire RNA structuromes. These advances in RNA structural biology have deepened insight into fundamental biological processes including gene editing, transcription, translation, and structure-based detection and response to temperature and other environmental signals. These discoveries reveal that RNA can be relatively static, like a rock; that it can have catalytic functions of cutting bonds, like scissors; and that it can adopt myriad functional shapes, like paper. We relate these extraordinary discoveries in the biology of RNA structure to the plant way of life. We trace plant-specific discovery of ribozymes and riboswitches, alternative splicing, organellar ribosomes, thermometers, whole-transcriptome structuromes and pan-structuromes, and conclude that plants have a special set of RNA structures that confer unique types of gene regulation. We finish with a consideration of future directions for the RNA structure-function field.
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Affiliation(s)
- Sarah M Assmann
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Hong-Li Chou
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Philip C Bevilacqua
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
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2
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Abstract
RNA interactions are exceptionally strong and highly redundant. As such, nearly any two RNAs have the potential to interact with one another over relatively short stretches, especially at high RNA concentrations. This is especially true for pairs of RNAs that do not form strong self-structure. Such phenomena can drive liquid-liquid phase separation, either solely from RNA-RNA interactions in the presence of divalent or organic cations, or in concert with proteins. RNA interactions can drive multimerization of RNA strands via both base-pairing and tertiary interactions. In this article, we explore the tendency of RNA to form stable monomers, dimers, and higher order structures as a function of RNA length and sequence through a focus on the intrinsic thermodynamic, kinetic, and structural properties of RNA. The principles we discuss are independent of any specific type of biomolecular condensate, and thus widely applicable. We also speculate how external conditions experienced by living organisms can influence the formation of nonmembranous compartments, again focusing on the physical and structural properties of RNA. Plants, in particular, are subject to diverse abiotic stresses including extreme temperatures, drought, and salinity. These stresses and the cellular responses to them, including changes in the concentrations of small molecules such as polyamines, salts, and compatible solutes, have the potential to regulate condensate formation by melting or strengthening base-pairing. Reversible condensate formation, perhaps including regulation by circadian rhythms, could impact biological processes in plants, and other organisms.
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Affiliation(s)
- Philip C Bevilacqua
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Biochemistry, Microbiology, and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Allison M Williams
- Department of Biochemistry, Microbiology, and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Hong-Li Chou
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Sarah M Assmann
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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3
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Abstract
Localization of mRNAs at the subcellular level is an essential mechanism for specific protein targeting and local control of protein synthesis in both eukaryotes and bacteria. While mRNA localization is well documented in metazoans, somatic cells, and microorganisms, only a handful of well-defined mRNA localization examples have been reported in vascular plants and algae. This review summarizes the function and mechanism of mRNA localization and highlights recent studies of mRNA localization in vascular plants. While the emphasis focuses on storage protein mRNA localization in rice endosperm cells, information on targeting of RNAs to organelles (chloroplasts and mitochondria) and plasmodesmata is also discussed.
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Affiliation(s)
- Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Hong-Li Chou
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Masako Fukuda
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Toshihiro Kumamaru
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
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4
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Chou HL, Tian L, Fukuda M, Kumamaru T, Okita TW. The Role of RNA-Binding Protein OsTudor-SN in Post-Transcriptional Regulation of Seed Storage Proteins and Endosperm Development. Plant Cell Physiol 2019; 60:2193-2205. [PMID: 31198964 DOI: 10.1093/pcp/pcz113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 05/28/2019] [Indexed: 05/28/2023]
Abstract
Tudor-SN is involved in a myriad of transcriptional and post-transcriptional processes due to its modular structure consisting of 4 tandem SN domains (4SN module) and C-terminal Tsn module consisting of Tudor-partial SN domains. We had previously demonstrated that OsTudor-SN is a key player for transporting storage protein mRNAs to specific ER subdomains in developing rice endosperm. Here, we provide genetic evidence that this multifunctional RBP is required for storage protein expression, seed development and protein body formation. The rice EM1084 line, possessing a nonsynonymous mutation in the 4SN module (SN3 domain), exhibited a strong reduction in grain weight and storage protein accumulation, while a mutation in the Tudor domain (47M) or the loss of the Tsn module (43M) had much smaller effects. Immunoelectron microscopic analysis showed the presence of a new protein body type containing glutelin and prolamine inclusions in EM1084, while 43M and 47M exhibited structurally modified prolamine and glutelin protein bodies. Transcriptome analysis indicates that OsTudor-SN also functions in regulating gene expression of transcriptional factors and genes involved in developmental processes and stress responses as well as for storage proteins. Normal protein body formation, grain weight and expression of many genes were partially restored in EM1084 transgenic line complemented with wild-type OsTudor-SN gene. Overall, our study showed that OsTudor-SN possesses multiple functional properties in rice storage protein expression and seed development and that the 4SN and Tsn modules have unique roles in these processes.
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Affiliation(s)
- Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
| | - Masako Fukuda
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, 744 Motooka Nishi-ku, Fukuoka, Japan
| | - Toshihiro Kumamaru
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, 744 Motooka Nishi-ku, Fukuoka, Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
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5
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Chou HL, Tian L, Washida H, Fukuda M, Kumamaru T, Okita TW. The rice storage protein mRNAs as a model system for RNA localization in higher plants. Plant Sci 2019; 284:203-211. [PMID: 31084873 DOI: 10.1016/j.plantsci.2019.04.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 04/09/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
The transport and targeting of mRNAs to specific intracellular locations is a ubiquitous process in prokaryotic and eukaryotic organisms. Despite the prevalent nature of RNA localization in guiding development, differentiation, cellular movement and intracellular organization of biochemical activities, only a few examples exist in higher plants. Here, we summarize past studies on mRNA-based protein targeting to specific subdomains of the cortical endoplasmic reticulum (ER) using the rice storage protein mRNAs as a model. Such studies have demonstrated that there are multiple pathways of RNA localization to the cortical ER that are controlled by cis-determinants (zipcodes) on the mRNA. These zipcode sequences are recognized by specific RNA binding proteins organized into multi-protein complexes. The available evidence suggests mRNAs are transported to their destination sites by co-opting membrane trafficking factors. Lastly, we discuss the major gaps in our knowledge on RNA localization and how information on the targeting of storage protein mRNAs can be used to further our understanding on how plant mRNAs are organized into regulons to facilitate protein localization and formation of multi-protein complexes.
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Affiliation(s)
- Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164-6340, United States
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164-6340, United States
| | - Haruhiko Washida
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164-6340, United States
| | - Masako Fukuda
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164-6340, United States; Faculty of Agriculture, Kyushu University, 744 Motooka Nishi-ku, Fukuoka, 819-0395, Japan
| | - Toshihiro Kumamaru
- Faculty of Agriculture, Kyushu University, 744 Motooka Nishi-ku, Fukuoka, 819-0395, Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164-6340, United States.
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6
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Cakir B, Tian L, Crofts N, Chou HL, Koper K, Ng CY, Tuncel A, Gargouri M, Hwang SK, Fujita N, Okita TW. Re-programming of gene expression in the CS8 rice line over-expressing ADPglucose pyrophosphorylase induces a suppressor of starch biosynthesis. Plant J 2019; 97:1073-1088. [PMID: 30523657 DOI: 10.1111/tpj.14180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/23/2018] [Accepted: 11/27/2018] [Indexed: 05/02/2023]
Abstract
The CS8 transgenic rice (Oryza sativa L.) lines expressing an up-regulated glgC gene produced higher levels of ADPglucose (ADPglc), the substrate for starch synthases. However, the increase in grain weight was much less than the increase in ADPglc levels suggesting one or more downstream rate-limiting steps. Endosperm starch levels were not further enhanced in double transgenic plants expressing both glgC and the maize brittle-1 gene, the latter responsible for transport of ADPglc into the amyloplast. These studies demonstrate that critical processes within the amyloplast stroma restrict maximum carbon flow into starch. RNA-seq analysis showed extensive re-programming of gene expression in the CS8 with 2073 genes up-regulated and 140 down-regulated. One conspicuous gene, up-regulated ~15-fold, coded for a biochemically uncharacterized starch binding domain-containing protein (SBDCP1) possessing a plastid transit peptide. Confocal microscopy and transmission electron microscopy analysis confirmed that SBDCP1 was located in the amyloplasts. Reciprocal immunoprecipitation and pull-down assays indicated an interaction between SBDCP1 and starch synthase IIIa (SSIIIa), which was down-regulated at the protein level in the CS8 line. Furthermore, binding by SBDCP1 inhibited SSIIIa starch polymerization activity in a non-competitive manner. Surprisingly, artificial microRNA gene suppression of SBDCP1 restored protein expression levels of SSIIIa in the CS8 line resulting in starch with lower amylose content and increased amylopectin chains with a higher degree of polymerization. Collectively, our results support the involvement of additional non-enzymatic factors such as SBDCP in starch biosynthesis.
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Affiliation(s)
- Bilal Cakir
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Naoko Crofts
- Faculty of Bioresource Science, Akita Prefectural University, Shimoshinjo-Nakano, Akita-City, 010-0195, Japan
| | - Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Kaan Koper
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Chun-Yeung Ng
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Aytug Tuncel
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Mahmoud Gargouri
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Seon-Kap Hwang
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Naoko Fujita
- Faculty of Bioresource Science, Akita Prefectural University, Shimoshinjo-Nakano, Akita-City, 010-0195, Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA, 99164, USA
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7
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Tian L, Chou HL, Zhang L, Okita TW. Targeted Endoplasmic Reticulum Localization of Storage Protein mRNAs Requires the RNA-Binding Protein RBP-L. Plant Physiol 2019; 179:1111-1131. [PMID: 30659066 PMCID: PMC6393789 DOI: 10.1104/pp.18.01434] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/11/2019] [Indexed: 05/18/2023]
Abstract
The transport and targeting of glutelin and prolamine mRNAs to distinct subdomains of the cortical endoplasmic reticulum is a model for mRNA localization in plants. This process requires a number of RNA-binding proteins (RBPs) that recognize and bind to mRNA cis-localization (zipcode) elements to form messenger ribonucleoprotein complexes, which then transport the RNAs to their destination sites at the cortical endoplasmic reticulum. Here, we present evidence that the rice (Oryza sativa) RNA-binding protein, RBP-L, like its interacting RBP-P partner, specifically binds to glutelin and prolamine zipcode RNA sequences and is required for proper mRNA localization in rice endosperm cells. A transfer DNA insertion in the 3' untranslated region resulted in reduced expression of the RBP-L gene to 10% to 25% of that in the wild-type. Reduced amounts of RBP-L caused partial mislocalization of glutelin and prolamine RNAs and conferred other general growth defects, including dwarfism, late flowering, and smaller seeds. Transcriptome analysis showed that RBP-L knockdown greatly affected the expression of prolamine family genes and several classes of transcription factors. Collectively, these results indicate that RBP-L, like RBP-P, is a key RBP involved in mRNA localization in rice endosperm cells. Moreover, distinct from RBP-P, RBP-L exhibits additional regulatory roles in development, either directly through its binding to corresponding RNAs or indirectly through its effect on transcription factors.
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Affiliation(s)
- Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Laining Zhang
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
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8
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Yang Y, Chou HL, Crofts AJ, Zhang L, Tian L, Washida H, Fukuda M, Kumamaru T, Oviedo OJ, Starkenburg SR, Okita TW. Selective sets of mRNAs localize to extracellular paramural bodies in a rice glup6 mutant. J Exp Bot 2018; 69:5045-5058. [PMID: 30102323 PMCID: PMC6189835 DOI: 10.1093/jxb/ery297] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/07/2018] [Indexed: 05/18/2023]
Abstract
The transport of rice glutelin storage proteins to the storage vacuoles requires the Rab5 GTPase and its related guanine nucleotide exchange factor (Rab5-GEF). Loss of function of these membrane vesicular trafficking factors results in the initial secretion of storage proteins and later their partial engulfment by the plasma membrane to form an extracellular paramural body (PMB), an aborted endosome complex. Here, we show that in the rice Rab5-GEF mutant glup6, glutelin RNAs are specifically mislocalized from their normal location on the cisternal endoplasmic reticulum (ER) to the protein body-ER, and are also apparently translocated to the PMBs. We substantiated the association of mRNAs with this aborted endosome complex by RNA-seq of PMBs purified by flow cytometry. Two PMB-associated groups of RNA were readily resolved: those that were specifically enriched in this aborted complex and those that were highly expressed in the cytoplasm. Examination of the PMB-enriched RNAs indicated that they were not a random sampling of the glup6 transcriptome but, instead, encompassed only a few functional mRNA classes. Although specific autophagy is also an alternative mechanism, our results support the view that RNA localization may co-opt membrane vesicular trafficking, and that many RNAs that share function or intracellular location are co-transported in developing rice seeds.
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Affiliation(s)
- Yongil Yang
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Present address: Institute of Agriculture, The University of Tennessee, Knoxville, TN 37996, USA
| | - Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Present address: The Huck Institutes of the Life Sciences, Pennsylvania State University, PA 16802, USA
| | - Andrew J Crofts
- International Liberal Arts Program, Akita International University, Akita, Japan
| | - Laining Zhang
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Haruhiko Washida
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Present Address: Organic Nico Co., Ltd, North #205, Kyodai Katsura Venture Plaza, 1–36, Goryo-Ohara, Nishikyo-ku, Kyoto 615–8245, Japan
| | - Masako Fukuda
- Faculty of Agriculture, Kyushu University, Motooka Nishi-ku, Fukuoka, Japan
| | - Toshihiro Kumamaru
- Faculty of Agriculture, Kyushu University, Motooka Nishi-ku, Fukuoka, Japan
| | | | | | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
- Correspondence:
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9
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Tian L, Chou HL, Zhang L, Hwang SK, Starkenburg SR, Doroshenk KA, Kumamaru T, Okita TW. RNA-Binding Protein RBP-P Is Required for Glutelin and Prolamine mRNA Localization in Rice Endosperm Cells. Plant Cell 2018; 30:2529-2552. [PMID: 30190374 PMCID: PMC6241268 DOI: 10.1105/tpc.18.00321] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 08/08/2018] [Accepted: 08/31/2018] [Indexed: 05/18/2023]
Abstract
In developing rice (Oryza sativa) endosperm, mRNAs of the major storage proteins, glutelin and prolamine, are transported and anchored to distinct subdomains of the cortical endoplasmic reticulum. RNA binding protein RBP-P binds to both glutelin and prolamine mRNAs, suggesting a role in some aspect of their RNA metabolism. Here, we show that rice lines expressing mutant RBP-P mislocalize both glutelin and prolamine mRNAs. Different mutant RBP-P proteins exhibited varying degrees of reduced RNA binding and/or protein-protein interaction properties, which may account for the mislocalization of storage protein RNAs. In addition, partial loss of RBP-P function conferred a broad phenotypic variation ranging from dwarfism, chlorophyll deficiency, and sterility to late flowering and low spikelet fertility. Transcriptome analysis highlighted the essential role of RBP-P in regulating storage protein genes and several essential biological processes during grain development. Overall, our data demonstrate the significant roles of RBP-P in glutelin and prolamine mRNA localization and in the regulation of genes important for plant growth and development through its RNA binding activity and cooperative regulation with interacting proteins.
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Affiliation(s)
- Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Laining Zhang
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Seon-Kap Hwang
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | | | - Kelly A Doroshenk
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | | | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
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10
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Chou HL, Tian L, Kumamaru T, Hamada S, Okita TW. Multifunctional RNA Binding Protein OsTudor-SN in Storage Protein mRNA Transport and Localization. Plant Physiol 2017; 175:1608-1623. [PMID: 29084903 PMCID: PMC5717745 DOI: 10.1104/pp.17.01388] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 10/26/2017] [Indexed: 05/04/2023]
Abstract
The multifunctional RNA-binding protein Tudor-SN plays multiple roles in transcriptional and posttranscriptional processes due to its modular domain structure, consisting of four tandem Staphylococcus nuclease (SN)-like domains (4SN), followed by a carboxyl-terminal Tudor domain, followed by a fifth partial SN sequence (Tsn). In plants, it confers stress tolerance, is a component of stress granules and P-bodies, and may participate in stabilizing and localizing RNAs to specific subdomains of the cortical-endoplasmic reticulum in developing rice (Oryza sativa) endosperm. Here, we show that, in addition to the intact rice OsTudor-SN protein, the 4SN and Tsn modules exist as independent polypeptides, which collectively may coassemble to form a complex population of homodimer and heteroduplex species. The 4SN and Tsn modules exhibit different roles in RNA binding and as a protein scaffold for stress-associated proteins and RNA-binding proteins. Despite their distinct individual properties, mutations in both the 4SN and Tsn modules mislocalize storage protein mRNAs to the cortical endoplasmic reticulum. These results indicate that the two modular peptide regions of OsTudor-SN confer different cellular properties but cooperate in mRNA localization, a process linking its multiple functions in the nucleus and cytoplasm.
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Affiliation(s)
- Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Toshihiro Kumamaru
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Shigeki Hamada
- Institute of Agriculture and Life Science, Hirosaki University, Hirosaki, Aomori 036-8561, Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
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11
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Kuo CY, Wang JY, Yeh CJ, Chen MC, Kuo CW, Chiang CY, Chou HL. Metal exposure for residents near diesel transport routes. J Environ Sci Health C Environ Carcinog Ecotoxicol Rev 2010; 28:22-38. [PMID: 20390966 DOI: 10.1080/10590500903585374] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
For the past few years, a large number of diesel vehicles carrying gravel and sand have shuttled back and forth every day on the main route (Tai-16 and Tai-21 highways) from Shuili to Shinyi in Nantou County, Taiwan, in support of a river-dredging project. Five stations along Tai-16 and three stations along Tai-21 were selected as the exposure sites. Two very small villages located about 9 and 12 kilometers, respectively, away from the diesel transport routes were selected as the control sites. In this study, five exposure pathways, i.e., ingestion from drinking water, household dust, rice, non-rice dishes, and inhalation from airborne particles, were considered. The daily intake doses of metals varied significantly among the five exposure pathways. There was a significant difference between the exposure and control sites regarding the doses of metals obtained from the exposure pathways of household dust and aerosols. However, regarding the exposure pathways of rice, non-rice dishes, and drinking water, no significant difference between the exposure and the control sites was observed for most metals. Residents who lived within 30 meters of diesel transport roads at the exposure sites were selected as the exposure groups for urine sampling, while residents of the control sites were selected as the control groups. The metal concentrations in the urine of the exposure groups were all higher than those of the control groups. With regards to the urinary metals Fe, Pb, Cu, Ni, and Mo, the levels of urinary metals in residents and the daily intakes of metals from the five exposure pathways showed that the exposure pathways from environmental media (i.e., drinking water, aerosols, and household dust) were a greater factor than food pathways (i.e., rice and non-rice dishes) in the resulting comparative differences between urinary concentration levels of Fe, Pb, Cu, and Mo in exposure groups and control groups. However, the food exposure pathways, rather than the environmental pathways, led to greater comparative differences between the urinary concentration levels of Mn within the two groups.
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Affiliation(s)
- Chung-Yih Kuo
- Department of Public Health, College of Health Care and Management, Chung Shan Medical University, Taichung, Taiwan, ROC.
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12
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Tseng YK, Tu WC, Lee HH, Chen KM, Chou HL, Lai SC. Ultrastructural localization of matrix metalloproteinase-9 in eosinophils from the cerebrospinal fluid of mice with eosinophilic meningitis caused by Angiostrongylus cantonensis. Ann Trop Med Parasitol 2005; 98:831-41. [PMID: 15667715 DOI: 10.1179/000349804x3199] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of eosinophilic meningitis caused by Angiostrongylus cantonensis. In the present study, such meningitis in mice was found to be associated with elevated expression of MMP-9 mRNA, elevated MMP-9 concentrations and enhanced MMP-9 activity in the cerebrospinal fluid (CSF). Immunocytochemistry showed that an anti-MMP-9 antibody reacted with macrophages, neutrophils and eosinophils from the CSF. As eosinophils are generally considered to be effector cells in host defence against A. cantonensis infection, high-resolution immuno-electron microscopy was then used to confirm the localization of MMP-9 in the eosinophils from the CSF. The method used, which was based on immunogold, indicated that the eosinophilic MMP-9 was mostly localized in the 'small' granules in the cytoplasm and along the cell membrane, and not in the crystalloid-containing secretory granules observed. It therefore appears that MMP-9 is synthesised and/or stored in the small granules of the eosinophils, and is released into the subarachnoid space of the host's brain by secretion or cell rupture.
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Affiliation(s)
- Y K Tseng
- Department of Entomology, National Chung-Hsing University, 250, Kuo-Kwang Road, Taichung 402, Taiwan
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13
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Hsu LS, Lee HH, Chen KM, Chou HL, Lai SC. Matrix metalloproteinase-2 and -9 in the granulomatous fibrosis of rats infected with Angiostrongylus cantonensis. Ann Trop Med Parasitol 2005; 99:61-70. [PMID: 15701257 DOI: 10.1179/136485905x19919] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The histomorphology of granuloma formation and gelatinase production were investigated in the brains, hearts, lungs and livers of Sprague-Dawley rats infected with Angiostrongylus cantonensis. The relationships between two gelatinases and granulomatous fibrosis were explored, following infection of each rat with 60 infective larvae of the nematode. Worm recovery from the brain was maximal on day 15 post-inoculation whereas peak recovery from the lungs was maximal 75 days later, on day 90. The granulomatous reactions and fibrosis were marked in the lungs but only mild, if present at all, in the brain, heart and liver. Gelatin zymography revealed that matrix metalloproteinase2 (MMP-2) was present, at all time-points, in the heart and lungs, although only in the lungs was there partial conversion of the 72-kDa pro-enzyme to the 64-kDa active form during granulomatous fibrosis. The activity of the MMP-9 pro-enzyme was significantly higher at the time-points when granuloma formation was observed than at other times. Immuno-histochemistry revealed MMP-2 and MMP-9 within the lung granulomas, around infiltrating leucocytes and the epithelial cells of the alveoli. As the granulomatous fibrosis appeared to be strongly associated with MMP-2 and MMP-9, these enzymes may be useful markers in the lungs of rats infected with A. cantonensis.
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Affiliation(s)
- L S Hsu
- Institute of Biochemistry, Chung Shan Medical University, 110, Section 1, Chien-Kuo North Road, Taichung 402, Taiwan
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Lee HH, Chou HL, Chen KM, Lai SC. Association of matrix metalloproteinase-9 in eosinophilic meningitis of BALB/c mice caused by Angiostrongylus cantonensis. Parasitol Res 2004; 94:321-8. [PMID: 15449178 DOI: 10.1007/s00436-004-1196-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Accepted: 07/15/2004] [Indexed: 11/26/2022]
Abstract
Induction of gelatinase in eosinophilic meningitis of BALB/c-strain mice was caused by Angiostrongylus cantonensis. Time-course studies showed that the molecular weight of 94-kDa gelatinase was detected at day 10 post-inoculation (PI), and reached a high intensity from days 15 to 25 PI. The 94-kDa gelatinase activity was clearly inhibited by EDTA and 1,10-phenanthroline, but not by leupeptin and phenylmethanesulphonyl fluoride. When immunoblots were performed using specific antiserums against the 94-kDa gelatinase B (matrix metalloproteinase-9; MMP-9) with cerebrospinal fluid (CSF), the 94-kDa immunopositive band was MMP-9. Immunohistochemistry studies demonstrated MMP-9 localisation within eosinophils and macrophages. The increased MMP-9 activity was closely associated with the rapid rise of CSF eosinophils, and the inflammatory reaction of the subarachnoid space. In contrast to changes in MMP-9, MMP-2 activity was constitutive and unaffected in this parasitic meningitis. These results show that MMP-9 was associated with eosinophilic meningitis, and that the enzyme may be a useful marker for angiostrongyliasis meningitis.
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Affiliation(s)
- H H Lee
- Department of Parasitology, Chung Shan Medical University, 402 Taichung, Taiwan
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Abstract
The authors tested the hypothesis in a rat model that hypervolemic hemodilution during heatstroke affected the mean arterial pressure (MAP), striatal dopamine (DA) release, and local cerebral blood flow and neuronal damage score in different brain structures. The heatstroke was induced by exposing the urethane-anesthetized rats to an ambient temperature of 42 degrees C. Hypervolemic hemodilution was produced by intravenous administration of 10% human albumin. Relative and absolute blood flow in the corpus striatum were determined using the laser Doppler flowmetry and the autoradiography diffusible tracer technique, respectively. The DA release in the striatum was estimated using the in vivo microdialysis technique. After onset of heatstroke, animals with hypervolemic state alone, produced by saline or heparinized blood injection, displayed higher values of DA release, as well as neuronal damage score in the striatum, hypothalamus, or cortex, but lower values of MAP and blood flow in the striatum, hypothalamus, or cortex compared to normothermic controls. However, the heatstroke-induced arterial hypotension, cerebral ischemia, increased striatal DA overload, and increased neuronal damage score were attenuated by induction of both hypervolemic and hemodilution state with 10% albumin either before or after the onset of heatstroke. In addition, constant infusions of a vasopressor agent phenylephrine (2 microg kg(-1) min(-1)) after the onset of heatstroke failed to maintain appropriate levels of MAP and resulted in no protection against heatstroke. Thus, it appears that the observed benefit of the 10% albumin is secondary to hemodilution and/or maintenance of MAP.
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Affiliation(s)
- C K Chang
- Department of Surgery, Mackay Memorial Hospital, Taipei, Taiwan
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Nishiya T, Chou HL. The study of lipid-protein interactions: effect of melittin on phase transition of phosphatidylethanolamine and sensitivity of phospholipases to phase state. J Biochem 1991; 110:732-6. [PMID: 1783603 DOI: 10.1093/oxfordjournals.jbchem.a123649] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The effects of melittin on the bilayer-to-inverted hexagonal (HII) phase transition of egg phosphatidylethanolamine (EPE) and the influence of the phase state of membrane matrix on hydrolysis of EPE by phospholipases have been studied. The phase transitions were measured using the fluorescent probe N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine (N-NBD-PE) and differential scanning calorimetry. In the presence of melittin at a lipid-to-melittin molar ratio (R1) of 200, 100, and 20, the phase transition of EPE disappeared, indicating that melittin stabilizes the bilayer structure. In the presence of 10 mol% of cholesterol, the phase transition temperature (TH) decreased and TH was observed even in the presence of melittin at R1 of 200 and 100. The fluorescence intensity of the tryptophan residue of melittin is sensitive to the phase transition and the wavelength of emission maxima shift from 352 to 337 nm upon addition of EPE and EPE-cholesterol (10 mol%) at R1 of 200. Kinetic parameters for phospholipase-catalyzed hydrolysis of EPE in bilayer and HII phases showed that HII phase of EPE is a poorer substrate for phospholipases and that cholesterol decreases the susceptibility of EPE to phospholipases.
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Affiliation(s)
- T Nishiya
- Artificial Cells and Organs Research Centre, McGill University, Montreal, PQ, Canada
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Chou HC, Huangfu M, Chou HL, Wei MH. Clinical evaluation of F30066 in long-course treatment of schistosomiasis japonica. Chin Med J 1965; 84:591-8. [PMID: 5325079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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