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Lancaster CL, Yalamanchili PS, Goldy JN, Leung SW, Corbett AH, Moberg KH. The RNA-binding protein Nab2 regulates levels of the RhoGEF Trio to govern axon and dendrite morphology. Mol Biol Cell 2024; 35:ar109. [PMID: 38985523 DOI: 10.1091/mbc.e24-04-0150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2024] Open
Abstract
The Drosophila RNA-binding protein (RBP) Nab2 acts in neurons to regulate neurodevelopment and is orthologous to the human intellectual disability-linked RBP, ZC3H14. Nab2 governs axon projection in mushroom body neurons and limits dendritic arborization of class IV sensory neurons in part by regulating splicing events in ∼150 mRNAs. Analysis of the Sex-lethal (Sxl) mRNA revealed that Nab2 promotes an exon-skipping event and regulates m6A methylation on Sxl pre-mRNA by the Mettl3 methyltransferase. Mettl3 heterozygosity broadly rescues Nab2null phenotypes implying that Nab2 acts through similar mechanisms on other RNAs, including unidentified targets involved in neurodevelopment. Here, we show that Nab2 and Mettl3 regulate the removal of a 5'UTR (untranslated region) intron in the trio pre-mRNA. Trio utilizes two GEF domains to balance Rac and RhoGTPase activity. Intriguingly, an isoform of Trio containing only the RhoGEF domain, GEF2, is depleted in Nab2null nervous tissue. Expression of Trio-GEF2 rescues projection defects in Nab2null axons and dendrites, while the GEF1 Rac1-regulatory domain exacerbates these defects, suggesting Nab2-mediated regulation Trio-GEF activities. Collectively, these data indicate that Nab2-regulated processing of trio is critical for balancing Trio-GEF1 and -GEF2 activity and show that Nab2, Mettl3, and Trio function in a common pathway that shapes axon and dendrite morphology.
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Affiliation(s)
- Carly L Lancaster
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Pranav S Yalamanchili
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
| | - Jordan N Goldy
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Sara W Leung
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
| | - Anita H Corbett
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
| | - Kenneth H Moberg
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
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2
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Palazzo AF, Qiu Y, Kang YM. mRNA nuclear export: how mRNA identity features distinguish functional RNAs from junk transcripts. RNA Biol 2024; 21:1-12. [PMID: 38091265 PMCID: PMC10732640 DOI: 10.1080/15476286.2023.2293339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2023] [Indexed: 12/18/2023] Open
Abstract
The division of the cellular space into nucleoplasm and cytoplasm promotes quality control mechanisms that prevent misprocessed mRNAs and junk RNAs from gaining access to the translational machinery. Here, we explore how properly processed mRNAs are distinguished from both misprocessed mRNAs and junk RNAs by the presence or absence of various 'identity features'.
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Affiliation(s)
| | - Yi Qiu
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Yoon Mo Kang
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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3
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Asada R, Dominguez A, Montpetit B. Single-molecule quantitation of RNA-binding protein occupancy and stoichiometry defines a role for Yra1 (Aly/REF) in nuclear mRNP organization. Cell Rep 2023; 42:113415. [PMID: 37963019 PMCID: PMC10841842 DOI: 10.1016/j.celrep.2023.113415] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 10/09/2023] [Accepted: 10/25/2023] [Indexed: 11/16/2023] Open
Abstract
RNA-binding proteins (RBPs) interact with mRNA to form supramolecular complexes called messenger ribonucleoprotein (mRNP) particles. These dynamic assemblies direct and regulate individual steps of gene expression; however, their composition and functional importance remain largely unknown. Here, we develop a total internal reflection fluorescence-based single-molecule imaging assay to investigate stoichiometry and co-occupancy of 15 RBPs within mRNPs from Saccharomyces cerevisiae. We show compositional heterogeneity of single mRNPs and plasticity across different growth conditions, with major co-occupants of mRNPs containing the nuclear cap-binding complex identified as Yra1 (1-10 copies), Nab2 (1-6 copies), and Npl3 (1-6 copies). Multicopy Yra1-bound mRNPs are specifically co-occupied by the THO complex and assembled on mRNAs biased by transcript length and RNA secondary structure. Yra1 depletion results in decreased compaction of nuclear mRNPs demonstrating a packaging function. Together, we provide a quantitative framework for gene- and condition-dependent RBP occupancy and stoichiometry in individual nuclear mRNPs.
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Affiliation(s)
- Ryuta Asada
- Department of Viticulture and Enology, University of California, Davis, Davis, CA 95616, USA
| | - Andrew Dominguez
- Department of Viticulture and Enology, University of California, Davis, Davis, CA 95616, USA; Biochemistry, Molecular, Cellular, and Developmental Biology Graduate Group, University of California, Davis, Davis, CA 95616, USA
| | - Ben Montpetit
- Department of Viticulture and Enology, University of California, Davis, Davis, CA 95616, USA; Biochemistry, Molecular, Cellular, and Developmental Biology Graduate Group, University of California, Davis, Davis, CA 95616, USA.
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4
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Joshua IM, Lin M, Mardjuki A, Mazzola A, Höfken T. A Protein-Protein Interaction Analysis Suggests a Wide Range of New Functions for the p21-Activated Kinase (PAK) Ste20. Int J Mol Sci 2023; 24:15916. [PMID: 37958899 PMCID: PMC10647699 DOI: 10.3390/ijms242115916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/25/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
The p21-activated kinases (PAKs) are important signaling proteins. They contribute to a surprisingly wide range of cellular processes and play critical roles in a number of human diseases including cancer, neurological disorders and cardiac diseases. To get a better understanding of PAK functions, mechanisms and integration of various cellular activities, we screened for proteins that bind to the budding yeast PAK Ste20 as an example, using the split-ubiquitin technique. We identified 56 proteins, most of them not described previously as Ste20 interactors. The proteins fall into a small number of functional categories such as vesicle transport and translation. We analyzed the roles of Ste20 in glucose metabolism and gene expression further. Ste20 has a well-established role in the adaptation to changing environmental conditions through the stimulation of mitogen-activated protein kinase (MAPK) pathways which eventually leads to transcription factor activation. This includes filamentous growth, an adaptation to nutrient depletion. Here we show that Ste20 also induces filamentous growth through interaction with nuclear proteins such as Sac3, Ctk1 and Hmt1, key regulators of gene expression. Combining our observations and the data published by others, we suggest that Ste20 has several new and unexpected functions.
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Affiliation(s)
| | - Meng Lin
- Institute of Biochemistry, Kiel University, 24118 Kiel, Germany
| | - Ariestia Mardjuki
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK; (I.M.J.)
| | - Alessandra Mazzola
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK; (I.M.J.)
- Department of Biopathology and Medical and Forensic Biotechnologies, University of Palermo, 90133 Palermo, Italy
| | - Thomas Höfken
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK; (I.M.J.)
- Institute of Biochemistry, Kiel University, 24118 Kiel, Germany
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5
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Jia Y, Yu X, Liu R, Shi L, Jin H, Yang D, Zhang X, Shen Y, Feng Y, Zhang P, Yang Y, Zhang L, Zhang P, Li Z, He A, Kong G. PRMT1 methylation of WTAP promotes multiple myeloma tumorigenesis by activating oxidative phosphorylation via m6A modification of NDUFS6. Cell Death Dis 2023; 14:512. [PMID: 37558663 PMCID: PMC10412649 DOI: 10.1038/s41419-023-06036-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 07/27/2023] [Accepted: 08/02/2023] [Indexed: 08/11/2023]
Abstract
Epigenetic modifications play important roles during the pathogenesis of multiple myeloma (MM). Herein, we found that protein arginine methyltransferase 1 (PRMT1) was highly expressed in MM patients, which was positively correlated with MM stages. High PRMT1 expression was correlated with adverse prognosis in MM patients. We further showed that silencing PRMT1 inhibited MM proliferation and tumorigenesis in vitro and in vivo. Mechanistically, we revealed that the knockdown of PRMT1 reduced the oxidative phosphorylation (OXPHOS) of MM cells through NDUFS6 downregulation. Meanwhile, we identified that WTAP, a key component of the m6A methyltransferase complex, was methylated by PRMT1, and NDUFS6 was identified as a bona fide m6A target of WTAP. Finally, we found that the combination of PRMT1 inhibitor and bortezomib synergistically inhibited MM progression. Collectively, our results demonstrate that PRMT1 plays a crucial role during MM tumorigenesis and suggeste that PRMT1 could be a potential therapeutic target in MM.
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Affiliation(s)
- Yachun Jia
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Xiao Yu
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Rui Liu
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Luyi Shi
- Precision Medical Institute, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Hua Jin
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
- Precision Medical Institute, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Dan Yang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Xiaofeng Zhang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Ying Shen
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Yuandong Feng
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Peihua Zhang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Yi Yang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
- Precision Medical Institute, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Linlin Zhang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
- Precision Medical Institute, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Pengyu Zhang
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Zongfang Li
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
| | - Aili He
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
| | - Guangyao Kong
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
- Department of Hematology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
- Precision Medical Institute, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
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The Plasmodium falciparum CCCH Zinc Finger Protein ZNF4 Plays an Important Role in Gametocyte Exflagellation through the Regulation of Male Enriched Transcripts. Cells 2022; 11:cells11101666. [PMID: 35626703 PMCID: PMC9139750 DOI: 10.3390/cells11101666] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/28/2022] [Accepted: 05/13/2022] [Indexed: 11/26/2022] Open
Abstract
CCCH zinc finger proteins (ZFPs) function mainly as RNA-binding proteins (RBPs) and play a central role in the mRNA metabolism. Over twenty seven CCCH-ZFPs are encoded in the genome of the human malaria parasite Plasmodium falciparum, the causative agent of malaria tropica. However, little is known about their functions. In this study, we characterize one member of the PfCCCH-ZFP named ZNF4. We show that ZNF4 is highly expressed in mature gametocytes, where it predominantly localizes to the cytoplasm. Targeted gene disruption of ZNF4 showed no significant effect in asexual blood stage replication and gametocyte development while male gametocyte exflagellation was significantly impaired, leading to reduced malaria transmission in the mosquito. Comparative transcriptomics between wildtype (WT) and the ZNF4-deficient line (ZNF4-KO) demonstrated the deregulation of about 473 genes (274 upregulated and 199 downregulated) in mature gametocytes. Most of the downregulated genes show peak expression in mature gametocyte with male enriched genes associated to the axonemal dynein complex formation, and cell projection organization is highly affected, pointing to the phenotype in male gametocyte exflagellation. Upregulated genes are associated to ATP synthesis. Our combined data therefore indicate that ZNF4 is a CCCH zinc finger protein which plays an important role in male gametocyte exflagellation through the regulation of male gametocyte-enriched genes.
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7
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Nuclear mRNA Export and Aging. Int J Mol Sci 2022; 23:ijms23105451. [PMID: 35628261 PMCID: PMC9142925 DOI: 10.3390/ijms23105451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 02/04/2023] Open
Abstract
The relationship between transcription and aging is one that has been studied intensively and experimentally with diverse attempts. However, the impact of the nuclear mRNA export on the aging process following its transcription is still poorly understood, although the nuclear events after transcription are coupled closely with the transcription pathway because the essential factors required for mRNA transport, namely TREX, TREX-2, and nuclear pore complex (NPC), physically and functionally interact with various transcription factors, including the activator/repressor and pre-mRNA processing factors. Dysregulation of the mediating factors for mRNA export from the nucleus generally leads to the aberrant accumulation of nuclear mRNA and further impairment in the vegetative growth and normal lifespan and the pathogenesis of neurodegenerative diseases. The optimal stoichiometry and density of NPC are destroyed during the process of cellular aging, and their damage triggers a defect of function in the nuclear permeability barrier. This review describes recent findings regarding the role of the nuclear mRNA export in cellular aging and age-related neurodegenerative disorders.
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8
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Zhang L, Sun K, Li Y, Ma T, Zhang Y, Yin Y, Zhang S, Shao W. The Importin FgPse1 Is Required for Vegetative Development, Virulence, and Deoxynivalenol Production by Interacting with the Nuclear Polyadenylated RNA-Binding Protein FgNab2 in Fusarium graminearum. PHYTOPATHOLOGY 2022; 112:1072-1080. [PMID: 34784736 DOI: 10.1094/phyto-08-21-0357-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Karyopherins are involved in transport through nuclear pore complexes. Karyopherins are necessary for nuclear import and export pathways and bind to their cargos. Polyadenylation of messenger RNA (mRNA) is necessary for various biological processes, regulating gene expression in eukaryotes. Until now, the association of karyopherin with mRNA polyadenylation has been less understood in plant pathogenic fungi. In our study, we focused on the biological functions of the karyopherin FgPse1 in Fusarium graminearum. The results showed that FgPse1 is involved in mycelial growth, asexual reproduction, virulence, and deoxynivalenol (DON) production. Co-immunoprecipitation and bimolecular fluorescence complementation showed that FgPse1 interacts with the nuclear polyadenylated RNA-binding protein FgNab2. Moreover, a fluorescence localization assay indicated that FgPse1 is necessary for the nuclear import of FgNab2. The nuclear import of FgNab2 regulates the expression of FgTri4, FgTri5, and FgTri6, which are essential for DON production. Thus, ΔFgPse1 and ΔFgNab2 showed consistent defects in DON production. In summary, our data indicated that FgPse1 is necessary for mycelial growth, virulence, and DON production, interacting with FgNab2 in F. graminearum. These results contribute to our understanding of the functions of importins in phytopathogenic fungi.
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Affiliation(s)
- Lixin Zhang
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Kewei Sun
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yiqing Li
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Tianling Ma
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yu Zhang
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
| | - Yanni Yin
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Shuai Zhang
- National Agro-technology Extension and Service Center, Beijing 100125, China
| | - Wenyong Shao
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
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9
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Rounds JC, Corgiat EB, Ye C, Behnke JA, Kelly SM, Corbett AH, Moberg KH. The disease-associated proteins Drosophila Nab2 and Ataxin-2 interact with shared RNAs and coregulate neuronal morphology. Genetics 2022; 220:iyab175. [PMID: 34791182 PMCID: PMC8733473 DOI: 10.1093/genetics/iyab175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 09/27/2021] [Indexed: 01/05/2023] Open
Abstract
Nab2 encodes the Drosophila melanogaster member of a conserved family of zinc finger polyadenosine RNA-binding proteins (RBPs) linked to multiple steps in post-transcriptional regulation. Mutation of the Nab2 human ortholog ZC3H14 gives rise to an autosomal recessive intellectual disability but understanding of Nab2/ZC3H14 function in metazoan nervous systems is limited, in part because no comprehensive identification of metazoan Nab2/ZC3H14-associated RNA transcripts has yet been conducted. Moreover, many Nab2/ZC3H14 functional protein partnerships remain unidentified. Here, we present evidence that Nab2 genetically interacts with Ataxin-2 (Atx2), which encodes a neuronal translational regulator, and that these factors coordinately regulate neuronal morphology, circadian behavior, and adult viability. We then present the first high-throughput identifications of Nab2- and Atx2-associated RNAs in Drosophila brain neurons using RNA immunoprecipitation-sequencing (RIP-Seq). Critically, the RNA interactomes of each RBP overlap, and Nab2 exhibits high specificity in its RNA associations in neurons in vivo, associating with a small fraction of all polyadenylated RNAs. The identities of shared associated transcripts (e.g., drk, me31B, stai) and of transcripts specific to Nab2 or Atx2 (e.g., Arpc2 and tea) promise insight into neuronal functions of, and genetic interactions between, each RBP. Consistent with prior biochemical studies, Nab2-associated neuronal RNAs are overrepresented for internal A-rich motifs, suggesting these sequences may partially mediate Nab2 target selection. These data support a model where Nab2 functionally opposes Atx2 in neurons, demonstrate Nab2 shares associated neuronal RNAs with Atx2, and reveal Drosophila Nab2 associates with a more specific subset of polyadenylated mRNAs than its polyadenosine affinity alone may suggest.
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Affiliation(s)
- J Christopher Rounds
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Edwin B Corgiat
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Changtian Ye
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Joseph A Behnke
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Seth M Kelly
- Department of Biology, The College of Wooster, Wooster, OH 44691, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Kenneth H Moberg
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
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10
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De Magistris P. The Great Escape: mRNA Export through the Nuclear Pore Complex. Int J Mol Sci 2021; 22:ijms222111767. [PMID: 34769195 PMCID: PMC8583845 DOI: 10.3390/ijms222111767] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/18/2021] [Accepted: 10/21/2021] [Indexed: 12/30/2022] Open
Abstract
Nuclear export of messenger RNA (mRNA) through the nuclear pore complex (NPC) is an indispensable step to ensure protein translation in the cytoplasm of eukaryotic cells. mRNA is not translocated on its own, but it forms ribonuclear particles (mRNPs) in association with proteins that are crucial for its metabolism, some of which; like Mex67/MTR2-NXF1/NXT1; are key players for its translocation to the cytoplasm. In this review, I will summarize our current body of knowledge on the basic characteristics of mRNA export through the NPC. To be granted passage, the mRNP cargo needs to bind transport receptors, which facilitate the nuclear export. During NPC transport, mRNPs undergo compositional and conformational changes. The interactions between mRNP and the central channel of NPC are described; together with the multiple quality control steps that mRNPs undergo at the different rings of the NPC to ensure only proper export of mature transcripts to the cytoplasm. I conclude by mentioning new opportunities that arise from bottom up approaches for a mechanistic understanding of nuclear export.
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11
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Corgiat EB, List SM, Rounds JC, Corbett AH, Moberg KH. The RNA-binding protein Nab2 regulates the proteome of the developing Drosophila brain. J Biol Chem 2021; 297:100877. [PMID: 34139237 PMCID: PMC8260979 DOI: 10.1016/j.jbc.2021.100877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 06/07/2021] [Accepted: 06/13/2021] [Indexed: 12/14/2022] Open
Abstract
The human ZC3H14 gene, which encodes a ubiquitously expressed polyadenosine zinc finger RNA-binding protein, is mutated in an inherited form of autosomal recessive, nonsyndromic intellectual disability. To gain insight into neurological functions of ZC3H14, we previously developed a Drosophila melanogaster model of ZC3H14 loss by deleting the fly ortholog, Nab2. Studies in this invertebrate model revealed that Nab2 controls final patterns of neuron projection within fully developed adult brains, but the role of Nab2 during development of the Drosophila brain is not known. Here, we identify roles for Nab2 in controlling the dynamic growth of axons in the developing brain mushroom bodies, which support olfactory learning and memory, and regulating abundance of a small fraction of the total brain proteome. The group of Nab2-regulated brain proteins, identified by quantitative proteomic analysis, includes the microtubule-binding protein Futsch, the neuronal Ig-family transmembrane protein turtle, the glial:neuron adhesion protein contactin, the Rac GTPase-activating protein tumbleweed, and the planar cell polarity factor Van Gogh, which collectively link Nab2 to the processes of brain morphogenesis, neuroblast proliferation, circadian sleep/wake cycles, and synaptic development. Overall, these data indicate that Nab2 controls the abundance of a subset of brain proteins during the active process of wiring the pupal brain mushroom body and thus provide a window into potentially conserved functions of the Nab2/ZC3H14 RNA-binding proteins in neurodevelopment.
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Affiliation(s)
- Edwin B Corgiat
- Department of Cell Biology, Emory University School of Medicine, Emory University, Atlanta, Georgia, USA; Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, Georgia, USA; Department of Biology, Emory University, Atlanta, Georgia, USA
| | - Sara M List
- Graduate Program in Neuroscience, Emory University, Atlanta, Georgia, USA
| | - J Christopher Rounds
- Department of Cell Biology, Emory University School of Medicine, Emory University, Atlanta, Georgia, USA; Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, Georgia, USA; Department of Biology, Emory University, Atlanta, Georgia, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, Georgia, USA.
| | - Kenneth H Moberg
- Department of Cell Biology, Emory University School of Medicine, Emory University, Atlanta, Georgia, USA.
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12
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Parbin S, Damodharan S, Rajyaguru PI. Arginine methylation and cytoplasmic mRNA fate: An exciting new partnership. Yeast 2021; 38:441-452. [PMID: 34048611 DOI: 10.1002/yea.3653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 05/12/2021] [Accepted: 05/20/2021] [Indexed: 12/22/2022] Open
Abstract
Posttranslational modifications play a crucial role in regulating gene expression. Among these modifications, arginine methylation has recently attracted tremendous attention due to its role in multiple cellular functions. This review discusses the recent advances that have established arginine methylation as a major player in determining cytoplasmic messenger RNA (mRNA) fate. We specifically focus on research that implicates arginine methylation in regulating mRNA translation, decay, and RNA granule dynamics. Based on this research, we highlight a few emerging future avenues that will lead to exciting discoveries in this field.
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Affiliation(s)
- Sabnam Parbin
- Department of Biochemistry, Indian Institute of Science, Bangalore, India.,Integrative Genomics Core Unit, University Medical Centre, Göttingen, Göttingen, Germany
| | - Subha Damodharan
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
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13
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Aguilar LC, Paul B, Reiter T, Gendron L, Arul Nambi Rajan A, Montpetit R, Trahan C, Pechmann S, Oeffinger M, Montpetit B. Altered rRNA processing disrupts nuclear RNA homeostasis via competition for the poly(A)-binding protein Nab2. Nucleic Acids Res 2020; 48:11675-11694. [PMID: 33137177 PMCID: PMC7672433 DOI: 10.1093/nar/gkaa964] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/06/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022] Open
Abstract
RNA-binding proteins (RBPs) are key mediators of RNA metabolism. Whereas some RBPs exhibit narrow transcript specificity, others function broadly across both coding and non-coding RNAs. Here, in Saccharomyces cerevisiae, we demonstrate that changes in RBP availability caused by disruptions to distinct cellular processes promote a common global breakdown in RNA metabolism and nuclear RNA homeostasis. Our data shows that stabilization of aberrant ribosomal RNA (rRNA) precursors in an enp1-1 mutant causes phenotypes similar to RNA exosome mutants due to nucleolar sequestration of the poly(A)-binding protein (PABP) Nab2. Decreased nuclear PABP availability is accompanied by genome-wide changes in RNA metabolism, including increased pervasive transcripts levels and snoRNA processing defects. These phenotypes are mitigated by overexpression of PABPs, inhibition of rDNA transcription, or alterations in TRAMP activity. Our results highlight the need for cells to maintain poly(A)-RNA levels in balance with PABPs and other RBPs with mutable substrate specificity across nucleoplasmic and nucleolar RNA processes.
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Affiliation(s)
- Lisbeth-Carolina Aguilar
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
| | - Biplab Paul
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Taylor Reiter
- Food Science Graduate Group, University of California Davis, Davis, CA, USA
| | - Louis Gendron
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Arvind Arul Nambi Rajan
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, CA, USA
| | - Rachel Montpetit
- Department of Viticulture and Enology, University of California Davis, Davis, CA, USA
| | - Christian Trahan
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
| | - Sebastian Pechmann
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Marlene Oeffinger
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
- Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Canada
- Food Science Graduate Group, University of California Davis, Davis, CA, USA
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, CA, USA
- Department of Viticulture and Enology, University of California Davis, Davis, CA, USA
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14
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Adams RL, Wente SR. Dbp5 associates with RNA-bound Mex67 and Nab2 and its localization at the nuclear pore complex is sufficient for mRNP export and cell viability. PLoS Genet 2020; 16:e1009033. [PMID: 33002012 PMCID: PMC7553267 DOI: 10.1371/journal.pgen.1009033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 10/13/2020] [Accepted: 08/06/2020] [Indexed: 01/04/2023] Open
Abstract
In Saccharomyces cerevisiae, the mRNA export receptor Mex67 is recruited to mature nuclear transcripts to mediate mRNA export through the nuclear pore complex (NPC) to the cytoplasm. Mex67 binds transcripts through adaptor proteins such as the poly(A) binding protein Nab2. When a transcript reaches the cytoplasmic face of the NPC, the DEAD-box protein Dbp5 acts to induce a local structural change to release Nab2 and Mex67 in an essential process termed mRNP remodeling. It is unknown how certain proteins (Nab2, Mex67) are released during Dbp5-mediated mRNP remodeling, whereas others remain associated. Here, we demonstrate that Dbp5 associates in close proximity with Mex67 and Nab2 in a cellular complex. Further, fusion of Dbp5 to Nup159 anchors Dbp5 at the cytoplasmic face of the NPC and is sufficient for cell viability. Thus, we speculate that the essential role of Dbp5 in remodeling exporting mRNPs requires its localization to the NPC and is separable from other subcellular functions of Dbp5. This work supports a model where the diverse nuclear, cytoplasmic and NPC functions of Dbp5 in the mRNA lifecycle are not interdependent and that Dbp5 is locally recruited through complex protein-protein interactions to select regions of transcripts for specific removal of transport proteins at the NPC.
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Affiliation(s)
- Rebecca L. Adams
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Susan R. Wente
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
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15
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Alpert T, Straube K, Carrillo Oesterreich F, Herzel L, Neugebauer KM. Widespread Transcriptional Readthrough Caused by Nab2 Depletion Leads to Chimeric Transcripts with Retained Introns. Cell Rep 2020; 33:108324. [PMID: 33113357 DOI: 10.1016/j.celrep.2020.108324] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 09/15/2020] [Accepted: 10/07/2020] [Indexed: 01/26/2023] Open
Abstract
Nascent RNA sequencing has revealed that pre-mRNA splicing can occur shortly after introns emerge from RNA polymerase II (RNA Pol II). Differences in co-transcriptional splicing profiles suggest regulation by cis- and/or trans-acting factors. Here, we use single-molecule intron tracking (SMIT) to identify a cohort of regulators by machine learning in budding yeast. Of these, Nab2 displays reduced co-transcriptional splicing when depleted. Unexpectedly, these splicing defects are attributable to aberrant "intrusive" transcriptional readthrough from upstream genes, as revealed by long-read sequencing. Transcripts that originate from the intron-containing gene's own transcription start site (TSS) are efficiently spliced, indicating no direct role of Nab2 in splicing per se. This work highlights the coupling between transcription, splicing, and 3' end formation in the context of gene organization along chromosomes. We conclude that Nab2 is required for proper 3' end processing, which ensures gene-specific control of co-transcriptional RNA processing.
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Affiliation(s)
- Tara Alpert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Korinna Straube
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | | | - Lydia Herzel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
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16
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Zarnack K, Balasubramanian S, Gantier MP, Kunetsky V, Kracht M, Schmitz ML, Sträßer K. Dynamic mRNP Remodeling in Response to Internal and External Stimuli. Biomolecules 2020; 10:biom10091310. [PMID: 32932892 PMCID: PMC7565591 DOI: 10.3390/biom10091310] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/02/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023] Open
Abstract
Signal transduction and the regulation of gene expression are fundamental processes in every cell. RNA-binding proteins (RBPs) play a key role in the post-transcriptional modulation of gene expression in response to both internal and external stimuli. However, how signaling pathways regulate the assembly of RBPs with mRNAs remains largely unknown. Here, we summarize observations showing that the formation and composition of messenger ribonucleoprotein particles (mRNPs) is dynamically remodeled in space and time by specific signaling cascades and the resulting post-translational modifications. The integration of signaling events with gene expression is key to the rapid adaptation of cells to environmental changes and stress. Only a combined approach analyzing the signal transduction pathways and the changes in post-transcriptional gene expression they cause will unravel the mechanisms coordinating these important cellular processes.
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Affiliation(s)
- Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, 60438 Frankfurt a.M., Germany;
| | | | - Michael P. Gantier
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia;
- Department of Molecular and Translational Science, Monash University, Clayton, VIC 3800, Australia
| | - Vladislav Kunetsky
- Institute of Biochemistry, FB08, Justus Liebig University, 35392 Giessen, Germany;
| | - Michael Kracht
- Rudolf Buchheim Institute of Pharmacology, FB11, Justus Liebig University, 35392 Giessen, Germany;
| | - M. Lienhard Schmitz
- Institute of Biochemistry, FB11, Justus Liebig University, 35392 Giessen, Germany;
| | - Katja Sträßer
- Institute of Biochemistry, FB08, Justus Liebig University, 35392 Giessen, Germany;
- Correspondence:
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17
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You ST, Jhou YT, Kao CF, Leu JY. Experimental evolution reveals a general role for the methyltransferase Hmt1 in noise buffering. PLoS Biol 2019; 17:e3000433. [PMID: 31613873 PMCID: PMC6814240 DOI: 10.1371/journal.pbio.3000433] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/25/2019] [Accepted: 09/27/2019] [Indexed: 11/19/2022] Open
Abstract
Cell-to-cell heterogeneity within an isogenic population has been observed in prokaryotic and eukaryotic cells. Such heterogeneity often manifests at the level of individual protein abundance and may have evolutionary benefits, especially for organisms in fluctuating environments. Although general features and the origins of cellular noise have been revealed, details of the molecular pathways underlying noise regulation remain elusive. Here, we used experimental evolution of Saccharomyces cerevisiae to select for mutations that increase reporter protein noise. By combining bulk segregant analysis and CRISPR/Cas9-based reconstitution, we identified the methyltransferase Hmt1 as a general regulator of noise buffering. Hmt1 methylation activity is critical for the evolved phenotype, and we also show that two of the Hmt1 methylation targets can suppress noise. Hmt1 functions as an environmental sensor to adjust noise levels in response to environmental cues. Moreover, Hmt1-mediated noise buffering is conserved in an evolutionarily distant yeast species, suggesting broad significance of noise regulation. Experimental evolution in yeast reveals that the methyltransferase Hmt1 functions as a mediator connecting environmental stimuli to cellular noise; Hmt1-mediated noise buffering is conserved in an evolutionarily distant yeast.
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Affiliation(s)
- Shu-Ting You
- Molecular and Cell Biology, Taiwan International Graduate Program, Graduate Institute of Life Sciences, National Defense Medical Center and Academia Sinica, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Ting Jhou
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Fu Kao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Jun-Yi Leu
- Molecular and Cell Biology, Taiwan International Graduate Program, Graduate Institute of Life Sciences, National Defense Medical Center and Academia Sinica, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- * E-mail:
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18
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Soheilypour M, Mofrad MRK. Quality control of mRNAs at the entry of the nuclear pore: Cooperation in a complex molecular system. Nucleus 2019; 9:202-211. [PMID: 29431587 PMCID: PMC5973141 DOI: 10.1080/19491034.2018.1439304] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Despite extensive research on how mRNAs are quality controlled prior to export into the cytoplasm, the exact underlying mechanisms are still under debate. Specifically, it is unclear how quality control proteins at the entry of the nuclear pore complex (NPC) distinguish normal and aberrant mRNAs. While some of the involved components are suggested to act as switches and recruit different factors to normal versus aberrant mRNAs, some experimental and computational evidence suggests that the combined effect of the regulated stochastic interactions between the involved components could potentially achieve an efficient quality control of mRNAs. In this review, we present a state-of-the-art portrait of the mRNA quality control research and discuss the current hypotheses proposed for dynamics of the cooperation between the involved components and how it leads to their shared goal: mRNA quality control prior to export into the cytoplasm.
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Affiliation(s)
- Mohammad Soheilypour
- a Molecular Cell Biomechanics Laboratory , Departments of Bioengineering and Mechanical Engineering, University of California , Berkeley
| | - Mohammad R K Mofrad
- a Molecular Cell Biomechanics Laboratory , Departments of Bioengineering and Mechanical Engineering, University of California , Berkeley
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19
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Xie Y, Ren Y. Mechanisms of nuclear mRNA export: A structural perspective. Traffic 2019; 20:829-840. [PMID: 31513326 DOI: 10.1111/tra.12691] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 08/26/2019] [Indexed: 12/28/2022]
Abstract
Export of mRNA from the nucleus to the cytoplasm is a critical process for all eukaryotic gene expression. As mRNA is synthesized, it is packaged with a myriad of RNA-binding proteins to form ribonucleoprotein particles (mRNPs). For each step in the processes of maturation and export, mRNPs must have the correct complement of proteins. Much of the mRNA export pathway revolves around the heterodimeric export receptor yeast Mex67•Mtr2/human NXF1•NXT1, which is recruited to signal the completion of nuclear mRNP assembly, mediates mRNP targeting/translocation through the nuclear pore complex (NPC), and is displaced at the cytoplasmic side of the NPC to release the mRNP into the cytoplasm. Directionality of the transport is governed by at least two DEAD-box ATPases, yeast Sub2/human UAP56 in the nucleus and yeast Dbp5/human DDX19 at the cytoplasmic side of the NPC, which respectively mediate the association and dissociation of Mex67•Mtr2/NXF1•NXT1 onto the mRNP. Here we review recent progress from structural studies of key constituents in different steps of nuclear mRNA export. These findings have laid the foundation for further studies to obtain a comprehensive mechanistic view of the mRNA export pathway.
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Affiliation(s)
- Yihu Xie
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Yi Ren
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee
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20
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Morris KJ, Corbett AH. The polyadenosine RNA-binding protein ZC3H14 interacts with the THO complex and coordinately regulates the processing of neuronal transcripts. Nucleic Acids Res 2019; 46:6561-6575. [PMID: 29912477 PMCID: PMC6061872 DOI: 10.1093/nar/gky446] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 06/13/2018] [Indexed: 12/14/2022] Open
Abstract
The polyadenosine RNA-binding protein ZC3H14 is important in RNA processing. Although ZC3H14 is ubiquitously expressed, mutation of the ZC3H14 gene causes a non-syndromic form of intellectual disability. Here, we examine the function of ZC3H14 in the brain by identifying ZC3H14-interacting proteins using unbiased mass spectrometry. Through this analysis, we identified physical interactions between ZC3H14 and multiple RNA processing factors. Notably, proteins that comprise the THO complex were amongst the most enriched proteins. We demonstrate that ZC3H14 physically interacts with THO components and that these proteins are required for proper RNA processing, as loss of ZC3H14 or THO components leads to extended bulk poly(A) tail length. Furthermore, we identified the transcripts Atp5g1 and Psd95 as shared RNA targets of ZC3H14 and the THO complex. Our data suggest that ZC3H14 and the THO complex are important for proper processing of Atp5g1 and Psd95 RNA, as depletion of ZC3H14 or THO components leads to decreased steady-state levels of each mature transcript accompanied by accumulation of Atp5g1 and Psd95 pre-mRNA in the cytoplasm. Taken together, this work provides the first unbiased identification of nuclear ZC3H14-interacting proteins from the brain and links the functions of ZC3H14 and the THO complex in the processing of RNA.
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Affiliation(s)
- Kevin J Morris
- Department of Biology, Emory University, Atlanta, GA 30322, USA.,Graduate Program in Biochemistry, Cell and Developmental Biology, James T. Laney Graduate School, Emory University, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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21
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Bauer I, Lechner L, Pidroni A, Petrone AM, Merschak P, Lindner H, Kremser L, Graessle S, Golderer G, Allipour S, Brosch G. Type I and II PRMTs regulate catabolic as well as detoxifying processes in Aspergillus nidulans. Fungal Genet Biol 2019; 129:86-100. [PMID: 31145992 DOI: 10.1016/j.fgb.2019.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 05/03/2019] [Accepted: 05/24/2019] [Indexed: 11/28/2022]
Abstract
In filamentous fungi, arginine methylation has been implicated in morphogenesis, mycotoxin biosynthesis, pathogenicity, and stress response although the exact role of this posttranslational modification in these processes remains obscure. Here, we present the first genome-wide transcriptome analysis in filamentous fungi that compared expression levels of genes regulated by type I and type II protein arginine methyltransferases (PRMTs). In Aspergillus nidulans, three conserved type I and II PRMTs are present that catalyze asymmetric or symmetric dimethylation of arginines. We generated a double type I mutant (ΔrmtA/rmtB) and a combined type I and type II mutant (ΔrmtB/rmtC) to perform genome-wide comparison of their effects on gene expression, but also to monitor putative overlapping activities and reciprocal regulations of type I and type II PRMTs in Aspergillus. Our study demonstrates, that rmtA and rmtC as type I and type II representatives act together as repressors of proteins that are secreted into the extracellular region as the majority of up-regulated genes are mainly involved in catabolic pathways that constitute the secretome of Aspergillus. In addition to a strong up-regulation of secretory genes we found a significant enrichment of down-regulated genes involved in processes related to oxidation-reduction, transmembrane transport and secondary metabolite biosynthesis. Strikingly, nearly 50% of down-regulated genes in both double mutants correspond to redox reaction/oxidoreductase processes, a remarkable finding in light of our recently observed oxidative stress phenotypes of ΔrmtA and ΔrmtC. Finally, analysis of nuclear and cytoplasmic extracts for mono-methylated proteins revealed the presence of both, common and specific substrates of RmtA and RmtC. Thus, our data indicate that type I and II PRMTs in Aspergillus seem to co-regulate the same biological processes but also specifically affect other pathways in a non-redundant fashion.
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Affiliation(s)
- Ingo Bauer
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Lukas Lechner
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Angelo Pidroni
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Anna-Maria Petrone
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Petra Merschak
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Herbert Lindner
- Division of Clinical Biochemistry, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Leopold Kremser
- Division of Clinical Biochemistry, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Stefan Graessle
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Georg Golderer
- Division of Biological Chemistry, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Shadab Allipour
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Gerald Brosch
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
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22
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Fasken MB, Corbett AH, Stewart M. Structure-function relationships in the Nab2 polyadenosine-RNA binding Zn finger protein family. Protein Sci 2019; 28:513-523. [PMID: 30578643 PMCID: PMC6371209 DOI: 10.1002/pro.3565] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/15/2018] [Accepted: 12/17/2018] [Indexed: 12/12/2022]
Abstract
The poly(A) RNA binding Zn finger ribonucleoprotein Nab2 functions to control the length of 3' poly(A) tails in Saccharomyces cerevisiae as well as contributing to the integration of the nuclear export of mature mRNA with preceding steps in the nuclear phase of the gene expression pathway. Nab2 is constructed from an N-terminal PWI-fold domain, followed by QQQP and RGG motifs and then seven CCCH Zn fingers. The nuclear pore-associated proteins Gfd1 and Mlp1 bind to opposite sides of the Nab2 N-terminal domain and function in the nuclear export of mRNA, whereas the Zn fingers, especially fingers 5-7, bind to A-rich regions of mature transcripts and function to regulate poly(A) tail length as well as mRNA compaction prior to nuclear export. Nab2 Zn fingers 5-7 have a defined spatial arrangement, with fingers 5 and 7 arranged on one side of the cluster and finger 6 on the other side. This spatial arrangement facilitates the dimerization of Nab2 when bound to adenine-rich RNAs and regulates both the termination of 3' polyadenylation and transcript compaction. Nab2 also functions to coordinate steps in the nuclear phase of the gene expression pathway, such as splicing and polyadenylation, with the generation of mature mRNA and its nuclear export. Nab2 orthologues in higher Eukaryotes have similar domain structures and play roles associated with the regulation of splicing and polyadenylation. Importantly, mutations in the gene encoding the human Nab2 orthologue ZC3H14 and cause intellectual disability.
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Affiliation(s)
- Milo B Fasken
- Department of Biology, Emory University, Atlanta, Georgia 30322
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, Georgia 30322
| | - Murray Stewart
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
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23
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Mechanism and Regulation of Co-transcriptional mRNP Assembly and Nuclear mRNA Export. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:1-31. [DOI: 10.1007/978-3-030-31434-7_1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Chia SZ, Lai YW, Yagoub D, Lev S, Hamey JJ, Pang CNI, Desmarini D, Chen Z, Djordjevic JT, Erce MA, Hart-Smith G, Wilkins MR. Knockout of the Hmt1p Arginine Methyltransferase in Saccharomyces cerevisiae Leads to the Dysregulation of Phosphate-associated Genes and Processes. Mol Cell Proteomics 2018; 17:2462-2479. [PMID: 30206180 PMCID: PMC6283299 DOI: 10.1074/mcp.ra117.000214] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/14/2018] [Indexed: 11/06/2022] Open
Abstract
Hmt1p is the predominant arginine methyltransferase in Saccharomyces cerevisiae Its substrate proteins are involved in transcription, transcriptional regulation, nucleocytoplasmic transport and RNA splicing. Hmt1p-catalyzed methylation can also modulate protein-protein interactions. Hmt1p is conserved from unicellular eukaryotes through to mammals where its ortholog, PRMT1, is lethal upon knockout. In yeast, however, the effect of knockout on the transcriptome and proteome has not been described. Transcriptome analysis revealed downregulation of phosphate-responsive genes in hmt1Δ, including acid phosphatases PHO5, PHO11, and PHO12, phosphate transporters PHO84 and PHO89 and the vacuolar transporter chaperone VTC3 Analysis of the hmt1Δ proteome revealed decreased abundance of phosphate-associated proteins including phosphate transporter Pho84p, vacuolar alkaline phosphatase Pho8p, acid phosphatase Pho3p and subunits of the vacuolar transporter chaperone complex Vtc1p, Vtc3p and Vtc4p. Consistent with this, phosphate homeostasis was dysregulated in hmt1Δ cells, showing decreased extracellular phosphatase levels and decreased total Pi in phosphate-depleted medium. In vitro, we showed that transcription factor Pho4p can be methylated at Arg-241, which could explain phosphate dysregulation in hmt1Δ if interplay exists with phosphorylation at Ser-242 or Ser-243, or if Arg-241 methylation affects the capacity of Pho4p to homodimerize or interact with Pho2p. However, the Arg-241 methylation site was not validated in vivo and the localization of a Pho4p-GFP fusion in hmt1Δ was not different from wild type. To our knowledge, this is the first study to reveal an association between Hmt1p and phosphate homeostasis and one which suggests a regulatory link between S-adenosyl methionine and intracellular phosphate.
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Affiliation(s)
- Samantha Z Chia
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Yu-Wen Lai
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Daniel Yagoub
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Sophie Lev
- Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute and Sydney Medical School, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
| | - Joshua J Hamey
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Chi Nam Ignatius Pang
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute and Sydney Medical School, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
| | - Zhiliang Chen
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Julianne T Djordjevic
- Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute and Sydney Medical School, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
| | - Melissa A Erce
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Gene Hart-Smith
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Marc R Wilkins
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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25
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Tudek A, Lloret-Llinares M, Jensen TH. The multitasking polyA tail: nuclear RNA maturation, degradation and export. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2018.0169. [PMID: 30397105 DOI: 10.1098/rstb.2018.0169] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2018] [Indexed: 12/17/2022] Open
Abstract
A polyA (pA) tail is an essential modification added to the 3' ends of a wide range of RNAs at different stages of their metabolism. Here, we describe the main sources of polyadenylation and outline their underlying biochemical interactions within the nuclei of budding yeast Saccharomyces cerevisiae, human cells and, when relevant, the fission yeast Schizosaccharomyces pombe Polyadenylation mediated by the S. cerevisiae Trf4/5 enzymes, and their human homologues PAPD5/7, typically leads to the 3'-end trimming or complete decay of non-coding RNAs. By contrast, the primary function of canonical pA polymerases (PAPs) is to produce stable and nuclear export-competent mRNAs. However, this dichotomy is becoming increasingly blurred, at least in S. pombe and human cells, where polyadenylation mediated by canonical PAPs may also result in transcript decay.This article is part of the theme issue '5' and 3' modifications controlling RNA degradation'.
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Affiliation(s)
- Agnieszka Tudek
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, building 1130, 8000 Aarhus C, Denmark
| | - Marta Lloret-Llinares
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, building 1130, 8000 Aarhus C, Denmark
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, building 1130, 8000 Aarhus C, Denmark
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26
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Tudek A, Schmid M, Makaras M, Barrass JD, Beggs JD, Jensen TH. A Nuclear Export Block Triggers the Decay of Newly Synthesized Polyadenylated RNA. Cell Rep 2018; 24:2457-2467.e7. [PMID: 30157437 PMCID: PMC6130047 DOI: 10.1016/j.celrep.2018.07.103] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 05/31/2018] [Accepted: 07/30/2018] [Indexed: 12/11/2022] Open
Abstract
Genomes are promiscuously transcribed, necessitating mechanisms that facilitate the sorting of RNA for function or destruction. The polyA (pA) tail is one such distinguishing feature, which in the Saccharomyces cerevisiae nucleus is bound by the Nab2p protein, yielding transcript protection. As Nab2p also contacts the main nuclear export factor Mex67p, we asked whether transport kinetics contributes to RNA sorting. Indeed, 3' end sequencing of newly transcribed pA+ RNAs demonstrates that nuclear depletion of Mex67p elicits their instant and global decay. A similar phenotype is evident upon inactivation of other export factors and proportional to the amount of nuclear pA+ RNA. As RNA expression is partially rescued by Nab2p overexpression, we propose that an export block out-titrates Nab2p onto nuclear-retained pA+ RNA, reducing the pool of Nab2p available to protect new transcripts. More generally, we suggest that nuclear RNA decay, negotiated by Nab2p availability, aids in balancing cellular transcript supply with demand.
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Affiliation(s)
- Agnieszka Tudek
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000 Aarhus C, Denmark
| | - Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000 Aarhus C, Denmark
| | - Marius Makaras
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000 Aarhus C, Denmark
| | - J David Barrass
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Jean D Beggs
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, C. F. Møllers Allé 3, Building 1130, 8000 Aarhus C, Denmark.
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27
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Chong PA, Vernon RM, Forman-Kay JD. RGG/RG Motif Regions in RNA Binding and Phase Separation. J Mol Biol 2018; 430:4650-4665. [PMID: 29913160 DOI: 10.1016/j.jmb.2018.06.014] [Citation(s) in RCA: 230] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/02/2018] [Accepted: 06/06/2018] [Indexed: 12/29/2022]
Abstract
RGG/RG motifs are RNA binding segments found in many proteins that can partition into membraneless organelles. They occur in the context of low-complexity disordered regions and often in multiple copies. Although short RGG/RG-containing regions can sometimes form high-affinity interactions with RNA structures, multiple RGG/RG repeats are generally required for high-affinity binding, suggestive of the dynamic, multivalent interactions that are thought to underlie phase separation in formation of cellular membraneless organelles. Arginine can interact with nucleotide bases via hydrogen bonding and π-stacking; thus, nucleotide conformers that provide access to the bases provide enhanced opportunities for RGG interactions. Methylation of RGG/RG regions, which is accomplished by protein arginine methyltransferase enzymes, occurs to different degrees in different cell types and may regulate the behavior of proteins containing these regions.
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Affiliation(s)
- P Andrew Chong
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Robert M Vernon
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Julie D Forman-Kay
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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28
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Bienkowski RS, Banerjee A, Rounds JC, Rha J, Omotade OF, Gross C, Morris KJ, Leung SW, Pak C, Jones SK, Santoro MR, Warren ST, Zheng JQ, Bassell GJ, Corbett AH, Moberg KH. The Conserved, Disease-Associated RNA Binding Protein dNab2 Interacts with the Fragile X Protein Ortholog in Drosophila Neurons. Cell Rep 2018; 20:1372-1384. [PMID: 28793261 DOI: 10.1016/j.celrep.2017.07.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/28/2017] [Accepted: 07/14/2017] [Indexed: 12/20/2022] Open
Abstract
The Drosophila dNab2 protein is an ortholog of human ZC3H14, a poly(A) RNA binding protein required for intellectual function. dNab2 supports memory and axon projection, but its molecular role in neurons is undefined. Here, we present a network of interactions that links dNab2 to cytoplasmic control of neuronal mRNAs in conjunction with the fragile X protein ortholog dFMRP. dNab2 and dfmr1 interact genetically in control of neurodevelopment and olfactory memory, and their encoded proteins co-localize in puncta within neuronal processes. dNab2 regulates CaMKII, but not futsch, implying a selective role in control of dFMRP-bound transcripts. Reciprocally, dFMRP and vertebrate FMRP restrict mRNA poly(A) tail length, similar to dNab2/ZC3H14. Parallel studies of murine hippocampal neurons indicate that ZC3H14 is also a cytoplasmic regulator of neuronal mRNAs. Altogether, these findings suggest that dNab2 represses expression of a subset of dFMRP-target mRNAs, which could underlie brain-specific defects in patients lacking ZC3H14.
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Affiliation(s)
- Rick S Bienkowski
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ayan Banerjee
- Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - J Christopher Rounds
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jennifer Rha
- Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Omotola F Omotade
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Christina Gross
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Kevin J Morris
- Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Sara W Leung
- Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - ChangHui Pak
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Stephanie K Jones
- Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Michael R Santoro
- Department of Human Genetics, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Stephen T Warren
- Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Human Genetics, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - James Q Zheng
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biochemistry, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Kenneth H Moberg
- Department of Cell Biology, Emory University and Emory University School of Medicine, Atlanta, GA 30322, USA.
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29
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Rha J, Jones SK, Fidler J, Banerjee A, Leung SW, Morris KJ, Wong JC, Inglis GAS, Shapiro L, Deng Q, Cutler AA, Hanif AM, Pardue MT, Schaffer A, Seyfried NT, Moberg KH, Bassell GJ, Escayg A, García PS, Corbett AH. The RNA-binding protein, ZC3H14, is required for proper poly(A) tail length control, expression of synaptic proteins, and brain function in mice. Hum Mol Genet 2018; 26:3663-3681. [PMID: 28666327 DOI: 10.1093/hmg/ddx248] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 06/20/2017] [Indexed: 12/30/2022] Open
Abstract
A number of mutations in genes that encode ubiquitously expressed RNA-binding proteins cause tissue specific disease. Many of these diseases are neurological in nature revealing critical roles for this class of proteins in the brain. We recently identified mutations in a gene that encodes a ubiquitously expressed polyadenosine RNA-binding protein, ZC3H14 (Zinc finger CysCysCysHis domain-containing protein 14), that cause a nonsyndromic, autosomal recessive form of intellectual disability. This finding reveals the molecular basis for disease and provides evidence that ZC3H14 is essential for proper brain function. To investigate the role of ZC3H14 in the mammalian brain, we generated a mouse in which the first common exon of the ZC3H14 gene, exon 13 is removed (Zc3h14Δex13/Δex13) leading to a truncated ZC3H14 protein. We report here that, as in the patients, Zc3h14 is not essential in mice. Utilizing these Zc3h14Δex13/Δex13mice, we provide the first in vivo functional characterization of ZC3H14 as a regulator of RNA poly(A) tail length. The Zc3h14Δex13/Δex13 mice show enlarged lateral ventricles in the brain as well as impaired working memory. Proteomic analysis comparing the hippocampi of Zc3h14+/+ and Zc3h14Δex13/Δex13 mice reveals dysregulation of several pathways that are important for proper brain function and thus sheds light onto which pathways are most affected by the loss of ZC3H14. Among the proteins increased in the hippocampi of Zc3h14Δex13/Δex13 mice compared to control are key synaptic proteins including CaMK2a. This newly generated mouse serves as a tool to study the function of ZC3H14 in vivo.
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Affiliation(s)
- Jennifer Rha
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322, USA
| | - Stephanie K Jones
- Department of Biology.,Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, GA 30322, USA
| | - Jonathan Fidler
- Department of Anesthesiology, Emory University School of Medicine & Research Division, Atlanta VA Medical Center, Atlanta, GA 30322, USA
| | | | | | - Kevin J Morris
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322, USA.,Department of Biology
| | - Jennifer C Wong
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - George Andrew S Inglis
- Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, GA 30322, USA.,Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Lindsey Shapiro
- Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, GA 30322, USA.,Graduate Program in Neuroscience, Emory University, Atlanta, GA 30322, USA
| | - Qiudong Deng
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Alicia A Cutler
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University, Atlanta, GA 30322, USA.,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Adam M Hanif
- Department of Opthamology, Emory University School of Medicine & Research Division, & Atlanta VA Medical Center, Atlanta, GA 30322, USA
| | - Machelle T Pardue
- Department of Opthamology, Emory University School of Medicine & Research Division, & Atlanta VA Medical Center, Atlanta, GA 30322, USA
| | - Ashleigh Schaffer
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4955, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kenneth H Moberg
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Andrew Escayg
- Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, GA 30322, USA
| | - Paul S García
- Department of Anesthesiology, Emory University School of Medicine & Research Division, Atlanta VA Medical Center, Atlanta, GA 30322, USA
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30
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Aibara S, Gordon JMB, Riesterer AS, McLaughlin SH, Stewart M. Structural basis for the dimerization of Nab2 generated by RNA binding provides insight into its contribution to both poly(A) tail length determination and transcript compaction in Saccharomyces cerevisiae. Nucleic Acids Res 2017; 45:1529-1538. [PMID: 28180315 PMCID: PMC5388407 DOI: 10.1093/nar/gkw1224] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/08/2016] [Accepted: 11/23/2016] [Indexed: 12/26/2022] Open
Abstract
In Saccharomyces cerevisiae generation of export-competent mRNPs terminates the nuclear phase of the gene expression pathway and facilitates transport to the cytoplasm for translation. Nab2 functions in this process to control both mRNP compaction that facilitates movement through nuclear pore complexes and the length of transcript poly(A) tails. Nab2 has a modular structure that includes seven CCCH Zn fingers that bind to A-rich RNAs and fingers 5–7 are critical for these functions. Here, we demonstrate, using both biophysical and structural methods, that binding A11G RNA induces dimerization of Zn fingers 5–7 mediated by the novel spatial arrangement of the fingers promoting each RNA chain binding two protein chains. The dimerization of Nab2 induced by RNA binding provides a basis for understanding its function in both poly(A) tail length regulation and in the compaction of mature transcripts to facilitate nuclear export.
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Affiliation(s)
- Shintaro Aibara
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - James M B Gordon
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Anja S Riesterer
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Stephen H McLaughlin
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Murray Stewart
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
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31
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Becker E, Com E, Lavigne R, Guilleux MH, Evrard B, Pineau C, Primig M. The protein expression landscape of mitosis and meiosis in diploid budding yeast. J Proteomics 2017; 156:5-19. [DOI: 10.1016/j.jprot.2016.12.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/14/2016] [Accepted: 12/26/2016] [Indexed: 12/12/2022]
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32
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Ariyachet C, Beißel C, Li X, Lorrey S, Mackenzie O, Martin PM, O'Brien K, Pholcharee T, Sim S, Krebber H, McBride AE. Post-translational modification directs nuclear and hyphal tip localization of Candida albicans mRNA-binding protein Slr1. Mol Microbiol 2017; 104:499-519. [PMID: 28187496 PMCID: PMC5405739 DOI: 10.1111/mmi.13643] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2017] [Indexed: 12/21/2022]
Abstract
The morphological transition of the opportunistic fungal pathogen Candida albicans from budding to hyphal growth has been implicated in its ability to cause disease in animal models. Absence of SR‐like RNA‐binding protein Slr1 slows hyphal formation and decreases virulence in a systemic candidiasis model, suggesting a role for post‐transcriptional regulation in these processes. SR (serine–arginine)‐rich proteins influence multiple steps in mRNA metabolism and their localization and function are frequently controlled by modification. We now demonstrate that Slr1 binds to polyadenylated RNA and that its intracellular localization is modulated by phosphorylation and methylation. Wildtype Slr1‐GFP is predominantly nuclear, but also co‐fractionates with translating ribosomes. The non‐phosphorylatable slr1‐6SA‐GFP protein, in which six serines in SR/RS clusters are substituted with alanines, primarily localizes to the cytoplasm in budding cells. Intriguingly, hyphal cells display a slr1‐6SA‐GFP focus at the tip near the Spitzenkörper, a vesicular structure involved in molecular trafficking to the tip. The presence of slr1‐6SA‐GFP hyphal tip foci is reduced in the absence of the mRNA‐transport protein She3, suggesting that unphosphorylated Slr1 associates with mRNA–protein complexes transported to the tip. The impact of SLR1 deletion on hyphal formation and function thus may be partially due to a role in hyphal mRNA transport.
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Affiliation(s)
| | - Christian Beißel
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften, Georg-August Universität Göttingen, Göttingen, Germany
| | - Xiang Li
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
| | - Selena Lorrey
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
| | | | | | | | | | - Sue Sim
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
| | - Heike Krebber
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften, Georg-August Universität Göttingen, Göttingen, Germany
| | - Anne E McBride
- Biology Department, Bowdoin College, Brunswick, ME, 04011, USA
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33
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Soheilypour M, Mofrad MRK. Regulation of RNA-binding proteins affinity to export receptors enables the nuclear basket proteins to distinguish and retain aberrant mRNAs. Sci Rep 2016; 6:35380. [PMID: 27805000 PMCID: PMC5090210 DOI: 10.1038/srep35380] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/23/2016] [Indexed: 02/06/2023] Open
Abstract
Export of messenger ribonucleic acids (mRNAs) into the cytoplasm is a fundamental step in gene regulation processes, which is meticulously quality controlled by highly efficient mechanisms in eukaryotic cells. Yet, it remains unclear how the aberrant mRNAs are recognized and retained inside the nucleus. Using a new modelling approach for complex systems, namely the agent-based modelling (ABM) approach, we develop a minimal model of the mRNA quality control (QC) mechanism. Our results demonstrate that regulation of the affinity of RNA-binding proteins (RBPs) to export receptors along with the weak interaction between the nuclear basket protein (Mlp1 or Tpr) and RBPs are the minimum requirements to distinguish and retain aberrant mRNAs. Our results show that the affinity between Tpr and RBPs is optimized to maximize the retention of aberrant mRNAs. In addition, we demonstrate how the length of mRNA affects the QC process. Since longer mRNAs spend more time in the nuclear basket to form a compact conformation and initiate their export, nuclear basket proteins could more easily capture and retain them inside the nucleus.
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Affiliation(s)
- M. Soheilypour
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA, 94720, USA
| | - M. R. K. Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA, 94720, USA
- Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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34
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Poornima G, Shah S, Vignesh V, Parker R, Rajyaguru PI. Arginine methylation promotes translation repression activity of eIF4G-binding protein, Scd6. Nucleic Acids Res 2016; 44:9358-9368. [PMID: 27613419 PMCID: PMC5100564 DOI: 10.1093/nar/gkw762] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 08/20/2016] [Indexed: 12/14/2022] Open
Abstract
Regulation of translation plays a critical role in determining mRNA fate. A new role was recently reported for a subset of RGG-motif proteins in repressing translation initiation by binding eIF4G1. However the signaling mechanism(s) that leads to spatial and temporal regulation of repression activity of RGG-motif proteins remains unknown. Here we report the role of arginine methylation in regulation of repression activity of Scd6, a conserved RGG-motif protein. We demonstrate that Scd6 gets arginine methylated at its RGG-motif and Hmt1 plays an important role in its methylation. We identify specific methylated arginine residues in the Scd6 RGG-motif in vivo We provide evidence that methylation augments Scd6 repression activity. Arginine methylation defective (AMD) mutant of Scd6 rescues the growth defect caused by overexpression of Scd6, a feature of translation repressors in general. Live-cell imaging of the AMD mutant revealed that it is defective in inducing formation of stress granules. Live-cell imaging and pull-down results indicate that it fails to bind eIF4G1 efficiently. Consistent with these results, a strain lacking Hmt1 is also defective in Scd6-eIF4G1 interaction. Our results establish that arginine methylation augments Scd6 repression activity by promoting eIF4G1-binding. We propose that arginine methylation of translation repressors with RGG-motif could be a general modulator of their repression activity.
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Affiliation(s)
- Gopalakrishna Poornima
- Department of Biochemistry, Indian Institute of Science, C V Raman Road, Bangalore 560012, India
| | - Shanaya Shah
- Department of Biochemistry, Indian Institute of Science, C V Raman Road, Bangalore 560012, India
| | | | - Roy Parker
- Department of Chemistry and Biochemistry, University of Colorado, 596 UCB, Boulder, CO 80309, USA
| | - Purusharth I Rajyaguru
- Department of Biochemistry, Indian Institute of Science, C V Raman Road, Bangalore 560012, India
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35
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Wigington CP, Morris KJ, Newman LE, Corbett AH. The Polyadenosine RNA-binding Protein, Zinc Finger Cys3His Protein 14 (ZC3H14), Regulates the Pre-mRNA Processing of a Key ATP Synthase Subunit mRNA. J Biol Chem 2016; 291:22442-22459. [PMID: 27563065 DOI: 10.1074/jbc.m116.754069] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 08/25/2016] [Indexed: 12/23/2022] Open
Abstract
Polyadenosine RNA-binding proteins (Pabs) regulate multiple steps in gene expression. This protein family includes the well studied Pabs, PABPN1 and PABPC1, as well as the newly characterized Pab, zinc finger CCCH-type containing protein 14 (ZC3H14). Mutations in ZC3H14 are linked to a form of intellectual disability. To probe the function of ZC3H14, we performed a transcriptome-wide analysis of cells depleted of either ZC3H14 or the control Pab, PABPN1. Depletion of PABPN1 affected ∼17% of expressed transcripts, whereas ZC3H14 affected only ∼1% of expressed transcripts. To assess the function of ZC3H14 in modulating target mRNAs, we selected the gene encoding the ATP synthase F0 subunit C (ATP5G1) transcript. Knockdown of ZC3H14 significantly reduced ATP5G1 steady-state mRNA levels. Consistent with results suggesting that ATP5G1 turnover increases upon depletion of ZC3H14, double knockdown of ZC3H14 and the nonsense-mediated decay factor, UPF1, rescues ATP5G1 transcript levels. Furthermore, fractionation reveals an increase in the amount of ATP5G1 pre-mRNA that reaches the cytoplasm when ZC3H14 is depleted and that ZC3H14 binds to ATP5G1 pre-mRNA in the nucleus. These data support a role for ZC3H14 in ensuring proper nuclear processing and retention of ATP5G1 pre-mRNA. Consistent with the observation that ATP5G1 is a rate-limiting component for ATP synthase activity, knockdown of ZC3H14 decreases cellular ATP levels and causes mitochondrial fragmentation. These data suggest that ZC3H14 modulates pre-mRNA processing of select mRNA transcripts and plays a critical role in regulating cellular energy levels, observations that have broad implications for proper neuronal function.
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Affiliation(s)
- Callie P Wigington
- From the Department of Biochemistry and.,the Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, Georgia 30322
| | - Kevin J Morris
- From the Department of Biochemistry and.,the Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, Georgia 30322
| | - Laura E Newman
- From the Department of Biochemistry and.,the Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, Georgia 30322
| | - Anita H Corbett
- From the Department of Biochemistry and .,the Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, Georgia 30322
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36
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The Evolutionarily-conserved Polyadenosine RNA Binding Protein, Nab2, Cooperates with Splicing Machinery to Regulate the Fate of pre-mRNA. Mol Cell Biol 2016; 36:2697-2714. [PMID: 27528618 PMCID: PMC5064217 DOI: 10.1128/mcb.00402-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Numerous RNA binding proteins are deposited onto an mRNA transcript to modulate post-transcriptional processing events ensuring proper mRNA maturation. Defining the interplay between RNA binding proteins that couple mRNA biogenesis events is crucial for understanding how gene expression is regulated. To explore how RNA binding proteins control mRNA processing, we investigated a role for the evolutionarily conserved polyadenosine RNA binding protein, Nab2, in mRNA maturation within the nucleus. This work reveals that nab2 mutant cells accumulate intron-containing pre-mRNA in vivo We extend this analysis to identify genetic interactions between mutant alleles of nab2 and genes encoding the splicing factor, MUD2, and the RNA exosome, RRP6, with in vivo consequences of altered pre-mRNA splicing and poly(A) tail length control. As further evidence linking Nab2 proteins to splicing, an unbiased proteomic analysis of vertebrate Nab2, ZC3H14, identifies physical interactions with numerous components of the spliceosome. We validated the interaction between ZC3H14 and U2AF2/U2AF65 Taking all the findings into consideration, we present a model where Nab2/ZC3H14 interacts with spliceosome components to allow proper coupling of splicing with subsequent mRNA processing steps contributing to a kinetic proofreading step that allows properly processed mRNA to exit the nucleus and escape Rrp6-dependent degradation.
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Plank M, Fischer R, Geoghegan V, Charles PD, Konietzny R, Acuto O, Pears C, Schofield CJ, Kessler BM. Expanding the yeast protein arginine methylome. Proteomics 2015; 15:3232-43. [DOI: 10.1002/pmic.201500032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/27/2015] [Accepted: 06/02/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Michael Plank
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
- Chemistry Research Laboratory; University of Oxford; Oxford UK
| | - Roman Fischer
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
| | - Vincent Geoghegan
- Sir William Dunn School of Pathology; University of Oxford; Oxford UK
| | - Philip D. Charles
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
| | - Rebecca Konietzny
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
| | - Oreste Acuto
- Sir William Dunn School of Pathology; University of Oxford; Oxford UK
| | | | | | - Benedikt M. Kessler
- Target Discovery Institute; Nuffield Department of Medicine; University of Oxford; Oxford UK
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Schmid M, Olszewski P, Pelechano V, Gupta I, Steinmetz LM, Jensen TH. The Nuclear PolyA-Binding Protein Nab2p Is Essential for mRNA Production. Cell Rep 2015; 12:128-139. [PMID: 26119729 DOI: 10.1016/j.celrep.2015.06.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 05/13/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022] Open
Abstract
Polyadenylation of mRNA is a key step in eukaryotic gene expression. However, despite the major impact of poly(A) tails on mRNA metabolism, the precise roles of poly(A)-binding proteins (PABPs) in nuclear mRNA biogenesis remain elusive. Here, we demonstrate that rapid nuclear depletion of the S. cerevisiae PABP Nab2p leads to a global loss of cellular mRNA, but not of RNA lacking poly(A) tails. Disappearance of mRNA is a nuclear event, but not due to decreased transcription. Instead, the absence of Nab2p results in robust nuclear mRNA decay by the ribonucleolytic RNA exosome in a polyadenylation-dependent process. We conclude that Nab2p is required to protect early mRNA and therefore constitutes a crucial nuclear mRNA biogenesis factor.
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Affiliation(s)
- Manfred Schmid
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, Building 1130, 8000 Aarhus C., Denmark.
| | - Pawel Olszewski
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, Building 1130, 8000 Aarhus C., Denmark
| | - Vicent Pelechano
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Ishaan Gupta
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Lars M Steinmetz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany; Stanford Genome Technology Center, Stanford University, Palo Alto, CA 94304, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Torben Heick Jensen
- Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Alle 3, Building 1130, 8000 Aarhus C., Denmark.
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Meinel DM, Sträßer K. Co-transcriptional mRNP formation is coordinated within a molecular mRNP packaging station in S. cerevisiae. Bioessays 2015; 37:666-77. [PMID: 25801414 PMCID: PMC5054900 DOI: 10.1002/bies.201400220] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In eukaryotes, the messenger RNA (mRNA), the blueprint of a protein‐coding gene, is processed and packaged into a messenger ribonucleoprotein particle (mRNP) by mRNA‐binding proteins in the nucleus. The steps of mRNP formation – transcription, processing, packaging, and the orchestrated release of the export‐competent mRNP from the site of transcription for nuclear mRNA export – are tightly coupled to ensure a highly efficient and regulated process. The importance of highly accurate nuclear mRNP formation is illustrated by the fact that mutations in components of this pathway lead to cellular inviability or to severe diseases in metazoans. We hypothesize that efficient mRNP formation is realized by a molecular mRNP packaging station, which is built by several recruitment platforms and coordinates the individual steps of mRNP formation.
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Affiliation(s)
- Dominik M Meinel
- Bavarian Health and Food Safety Authority, Oberschleißheim, Germany
| | - Katja Sträßer
- Institute of Biochemistry, Justus Liebig University Giessen, Giessen, Germany
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Wigington CP, Williams KR, Meers MP, Bassell GJ, Corbett AH. Poly(A) RNA-binding proteins and polyadenosine RNA: new members and novel functions. WILEY INTERDISCIPLINARY REVIEWS. RNA 2014; 5:601-22. [PMID: 24789627 PMCID: PMC4332543 DOI: 10.1002/wrna.1233] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/07/2014] [Accepted: 03/06/2014] [Indexed: 02/05/2023]
Abstract
Poly(A) RNA-binding proteins (Pabs) bind with high affinity and specificity to polyadenosine RNA. Textbook models show a nuclear Pab, PABPN1, and a cytoplasmic Pab, PABPC, where the nuclear PABPN1 modulates poly(A) tail length and the cytoplasmic PABPC stabilizes poly(A) RNA in the cytoplasm and also enhances translation. While these conventional roles are critically important, the Pab family has expanded recently both in number and in function. A number of novel roles have emerged for both PAPBPN1 and PABPC that contribute to the fine-tuning of gene expression. Furthermore, as the characterization of the nucleic acid binding properties of RNA-binding proteins advances, additional proteins that show high affinity and specificity for polyadenosine RNA are being discovered. With this expansion of the Pab family comes a concomitant increase in the potential for Pabs to modulate gene expression. Further complication comes from an expansion of the potential binding sites for Pab proteins as revealed by an analysis of templated polyadenosine stretches present within the transcriptome. Thus, Pabs could influence mRNA fate and function not only by binding to the nontemplated poly(A) tail but also to internal stretches of adenosine. Understanding the diverse functions of Pab proteins is not only critical to understand how gene expression is regulated but also to understand the molecular basis for tissue-specific diseases that occur when Pab proteins are altered. Here we describe both conventional and recently emerged functions for PABPN1 and PABPC and then introduce and discuss three new Pab family members, ZC3H14, hnRNP-Q1, and LARP4.
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Affiliation(s)
- Callie P. Wigington
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Kathryn R. Williams
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Michael P. Meers
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, USA
| | - Gary J. Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Anita H. Corbett
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
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Baejen C, Torkler P, Gressel S, Essig K, Söding J, Cramer P. Transcriptome Maps of mRNP Biogenesis Factors Define Pre-mRNA Recognition. Mol Cell 2014; 55:745-57. [DOI: 10.1016/j.molcel.2014.08.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/08/2014] [Accepted: 07/31/2014] [Indexed: 12/15/2022]
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Santos-Pereira JM, Herrero AB, Moreno S, Aguilera A. Npl3, a new link between RNA-binding proteins and the maintenance of genome integrity. Cell Cycle 2014; 13:1524-9. [PMID: 24694687 DOI: 10.4161/cc.28708] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The mRNA is co-transcriptionally bound by a number of RNA-binding proteins (RBPs) that contribute to its processing and formation of an export-competent messenger ribonucleoprotein particle (mRNP). In the last few years, increasing evidence suggests that RBPs play a key role in preventing transcription-associated genome instability. Part of this instability is mediated by the accumulation of co-transcriptional R loops, which may impair replication fork (RF) progression due to collisions between transcription and replication machineries. In addition, some RBPs have been implicated in DNA repair and/or the DNA damage response (DDR). Recently, the Npl3 protein, one of the most abundant heterogeneous nuclear ribonucleoproteins (hnRNPs) in yeast, has been shown to prevent transcription-associated genome instability and accumulation of RF obstacles, partially associated with R-loop formation. Interestingly, Npl3 seems to have additional functions in DNA repair, and npl3∆ mutants are highly sensitive to genotoxic agents, such as the antitumor drug trabectedin. Here we discuss the role of Npl3 in particular, and RBPs in general, in the connection of transcription with replication and genome instability, and its effect on the DDR.
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Affiliation(s)
- José M Santos-Pereira
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER; Universidad de Sevilla-CSIC; Seville, Spain
| | - Ana B Herrero
- Instituto de Biología Molecular y Celular del Cáncer; Universidad de Salamanca-CSIC; Salamanca, Spain
| | - Sergio Moreno
- Instituto de Biología Funcional y Genómica; Universidad de Salamanca-CSIC; Salamanca, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER; Universidad de Sevilla-CSIC; Seville, Spain
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Ladror DT, Frey BL, Scalf M, Levenstein ME, Artymiuk JM, Smith LM. Methylation of yeast ribosomal protein S2 is elevated during stationary phase growth conditions. Biochem Biophys Res Commun 2014; 445:535-41. [PMID: 24486316 DOI: 10.1016/j.bbrc.2014.01.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Accepted: 01/14/2014] [Indexed: 01/12/2023]
Abstract
Ribosomes, as the center of protein translation in the cell, require careful regulation via multiple pathways. While regulation of ribosomal synthesis and function has been widely studied on the transcriptional and translational "levels," the biological roles of ribosomal post-translational modifications (PTMs) are largely not understood. Here, we explore this matter by using quantitative mass spectrometry to compare the prevalence of ribosomal methylation and acetylation for yeast in the log phase and the stationary phase of growth. We find that of the 27 modified peptides identified, two peptides experience statistically significant changes in abundance: a 1.9-fold decrease in methylation for k(Me)VSGFKDEVLETV of ribosomal protein S1B (RPS1B), and a 10-fold increase in dimethylation for r(DiMe)GGFGGR of ribosomal protein S2 (RPS2). While the biological role of RPS1B methylation has largely been unexplored, RPS2 methylation is a modification known to have a role in processing and export of ribosomal RNA. This suggests that yeast in the stationary phase increase methylation of RPS2 in order to regulate ribosomal synthesis. These results demonstrate the utility of mass spectrometry for quantifying dynamic changes in ribosomal PTMs.
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Affiliation(s)
- Daniel T Ladror
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Brian L Frey
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Mark Scalf
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Mark E Levenstein
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Jacklyn M Artymiuk
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
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Poly(A) tail-mediated gene regulation by opposing roles of Nab2 and Pab2 nuclear poly(A)-binding proteins in pre-mRNA decay. Mol Cell Biol 2013; 33:4718-31. [PMID: 24081329 DOI: 10.1128/mcb.00887-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The 3' end of most eukaryotic transcripts is decorated by poly(A)-binding proteins (PABPs), which influence the fate of mRNAs throughout gene expression. However, despite the fact that multiple PABPs coexist in the nuclei of most eukaryotes, how functional interplay between these nuclear PABPs controls gene expression remains unclear. By characterizing the ortholog of the Nab2/ZC3H14 zinc finger PABP in Schizosaccharomyces pombe, we show here that the two major fission yeast nuclear PABPs, Pab2 and Nab2, have opposing roles in posttranscriptional gene regulation. Notably, we find that Nab2 functions in gene-specific regulation in a manner opposite to that of Pab2. By studying the ribosomal-protein-coding gene rpl30-2, which is negatively regulated by Pab2 via a nuclear pre-mRNA decay pathway that depends on the nuclear exosome subunit Rrp6, we show that Nab2 promotes rpl30-2 expression by acting at the level of the unspliced pre-mRNA. Our data support a model in which Nab2 impedes Pab2/Rrp6-mediated decay by competing with Pab2 for polyadenylated transcripts in the nucleus. The opposing roles of Pab2 and Nab2 reveal that interplay between nuclear PABPs can influence gene regulation.
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Kuhlmann SI, Valkov E, Stewart M. Structural basis for the molecular recognition of polyadenosine RNA by Nab2 Zn fingers. Nucleic Acids Res 2013; 42:672-80. [PMID: 24071581 PMCID: PMC3874189 DOI: 10.1093/nar/gkt876] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The yeast poly(A) RNA binding protein, Nab2, facilitates poly(A) tail length regulation together with targeting transcripts to nuclear pores and their export to the cytoplasm. Nab2 binds polyadenosine RNA primarily through a tandem repeat of CCCH Zn fingers. We report here the 2.15 Å resolution crystal structure of Zn fingers 3–5 of Chaetomium thermophilum Nab2 bound to polyadenosine RNA and establish the structural basis for the molecular recognition of adenosine ribonucleotides. Zn fingers 3 and 5 each bind two adenines, whereas finger 4 binds only one. In each case, the purine ring binds in a surface groove, where it stacks against an aromatic side chain, with specificity being provided by a novel pattern of H-bonds, most commonly between purine N6 and a Zn-coordinated cysteine supplemented by H-bonds between purine N7 and backbone amides. Residues critical for adenine binding are conserved between species and provide a code that allows prediction of finger-binding stoichiometry based on their sequence. Moreover, these results indicate that, in addition to poly(A) tails, Nab2 can also recognize sequence motifs elsewhere in transcripts in which adenosines are placed at key positions, consistent with its function in mRNP organization and compaction as well as poly(A) tail length regulation.
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Affiliation(s)
- Sonja I Kuhlmann
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
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Low JK, Hart-Smith G, Erce MA, Wilkins MR. Analysis of the Proteome of Saccharomyces cerevisiae for Methylarginine. J Proteome Res 2013; 12:3884-99. [DOI: 10.1021/pr400556c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Jason K.K. Low
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
| | - Gene Hart-Smith
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
| | - Melissa A. Erce
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
| | - Marc R. Wilkins
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
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Affiliation(s)
- C A Niño
- Institut Jacques Monod, Paris Diderot University , Sorbonne Paris Cité, CNRS UMR7592, Equipe labellisée Ligue contre le cancer, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
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Identification of a novel lipin homologue from the parasitic protozoan Trypanosoma brucei. BMC Microbiol 2013; 13:101. [PMID: 23656927 PMCID: PMC3654991 DOI: 10.1186/1471-2180-13-101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 05/06/2013] [Indexed: 02/03/2023] Open
Abstract
Background Arginine methylation is a post-translational modification that expands the functional diversity of proteins. Kinetoplastid parasites contain a relatively large group of protein arginine methyltransferases (PRMTs) compared to other single celled eukaryotes. Several T. brucei proteins have been shown to serve as TbPRMT substrates in vitro, and a great number of proteins likely to undergo methylation are predicted by the T. brucei genome. This indicates that a large number of proteins whose functions are modulated by arginine methylation await discovery in trypanosomes. Here, we employed a yeast two-hybrid screen using as bait the major T. brucei type I PRMT, TbPRMT1, to identify potential substrates of this enzyme. Results We identified a protein containing N-LIP and C-LIP domains that we term TbLpn. These domains are usually present in a family of proteins known as lipins, and involved in phospholipid biosynthesis and gene regulation. Far western and co-immunoprecipitation assays confirmed the TbPRMT1-TbLpn interaction. We also demonstrated that TbLpn is localized mainly to the cytosol, and is methylated in vivo. In addition, we showed that, similar to mammalian and yeast proteins with N-LIP and C-LIP domains, recombinant TbLpn exhibits phosphatidic acid phosphatase activity, and that two conserved aspartic acid residues present in the C-LIP domain are critical for its enzymatic activity. Conclusions This study reports the characterization of a novel trypanosome protein and provides insight into its enzymatic activity and function in phospholipid biosynthesis. It also indicates that TbLpn functions may be modulated by arginine methylation.
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Klass DM, Scheibe M, Butter F, Hogan GJ, Mann M, Brown PO. Quantitative proteomic analysis reveals concurrent RNA-protein interactions and identifies new RNA-binding proteins in Saccharomyces cerevisiae. Genome Res 2013; 23:1028-38. [PMID: 23636942 PMCID: PMC3668357 DOI: 10.1101/gr.153031.112] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A growing body of evidence supports the existence of an extensive network of RNA-binding proteins (RBPs) whose combinatorial binding affects the post-transcriptional fate of every mRNA in the cell—yet we still do not have a complete understanding of which proteins bind to mRNA, which of these bind concurrently, and when and where in the cell they bind. We describe here a method to identify the proteins that bind to RNA concurrently with an RBP of interest, using quantitative mass spectrometry combined with RNase treatment of affinity-purified RNA–protein complexes. We applied this method to the known RBPs Pab1, Nab2, and Puf3. Our method significantly enriched for known RBPs and is a clear improvement upon previous approaches in yeast. Our data reveal that some reported protein–protein interactions may instead reflect simultaneous binding to shared RNA targets. We also discovered more than 100 candidate RBPs, and we independently confirmed that 77% (23/30) bind directly to RNA. The previously recognized functions of the confirmed novel RBPs were remarkably diverse, and we mapped the RNA-binding region of one of these proteins, the transcriptional coactivator Mbf1, to a region distinct from its DNA-binding domain. Our results also provided new insights into the roles of Nab2 and Puf3 in post-transcriptional regulation by identifying other RBPs that bind simultaneously to the same mRNAs. While existing methods can identify sets of RBPs that interact with common RNA targets, our approach can determine which of those interactions are concurrent—a crucial distinction for understanding post-transcriptional regulation.
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Affiliation(s)
- Daniel M Klass
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California 94305, USA
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