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Anderson G, Jang C, Wang R, Goodin M. Mapping the nuclear localization signal in the matrix protein of potato yellow dwarf virus. J Gen Virol 2018; 99:743-752. [PMID: 29616892 DOI: 10.1099/jgv.0.001051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The ability of the matrix (M) protein of potato yellow dwarf virus (PYDV) to remodel nuclear membranes is controlled by a di-leucine motif located at residues 223 and 224 of its primary structure. This function can be uncoupled from that of its nuclear localization signal (NLS), which is controlled primarily by lysine and arginine residues immediately downstream of the LL motif. In planta localization of green fluorescent protein fusions, bimolecular fluorescence complementation assays with nuclear import receptor importin-α1 and yeast-based nuclear import assays provided three independent experimental approaches to validate the authenticity of the M-NLS. The carboxy terminus of M is predicted to contain a nuclear export signal, which is belived to be functional, given the ability of M to bind the Arabidopsis nuclear export receptor 1 (XPO1). The nuclear shuttle activity of M has implications for the cell-to-cell movement of PYDV nucleocapsids, based upon its interaction with the N and Y proteins.
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Affiliation(s)
- Gavin Anderson
- Anderson Craft Ales, 1030 Elias St, London, ON N5W 3P6, Canada
| | - Chanyong Jang
- Department of Plant Pathology, University of Kentucky, Lexington, KY, USA
| | - Renyuan Wang
- Department of Plant Pathology, University of Kentucky, Lexington, KY, USA
| | - Michael Goodin
- Department of Plant Pathology, University of Kentucky, Lexington, KY, USA
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Luan H, Shine MB, Cui X, Chen X, Ma N, Kachroo P, Zhi H, Kachroo A. The Potyviral P3 Protein Targets Eukaryotic Elongation Factor 1A to Promote the Unfolded Protein Response and Viral Pathogenesis. PLANT PHYSIOLOGY 2016; 172:221-34. [PMID: 27356973 PMCID: PMC5074642 DOI: 10.1104/pp.16.00505] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/14/2016] [Indexed: 05/21/2023]
Abstract
The biochemical function of the potyviral P3 protein is not known, although it is known to regulate virus replication, movement, and pathogenesis. We show that P3, the putative virulence determinant of soybean mosaic virus (SMV), targets a component of the translation elongation complex in soybean. Eukaryotic elongation factor 1A (eEF1A), a well-known host factor in viral pathogenesis, is essential for SMV virulence and the associated unfolded protein response (UPR). Silencing GmEF1A inhibits accumulation of SMV and another ER-associated virus in soybean. Conversely, endoplasmic reticulum (ER) stress-inducing chemicals promote SMV accumulation in wild-type, but not GmEF1A-knockdown, plants. Knockdown of genes encoding the eEF1B isoform, which is important for eEF1A function in translation elongation, has similar effects on UPR and SMV resistance, suggesting a link to translation elongation. P3 and GmEF1A promote each other's nuclear localization, similar to the nuclear-cytoplasmic transport of eEF1A by the Human immunodeficiency virus 1 Nef protein. Our results suggest that P3 targets host elongation factors resulting in UPR, which in turn facilitates SMV replication and place eEF1A upstream of BiP in the ER stress response during pathogen infection.
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Affiliation(s)
- Hexiang Luan
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
| | - M B Shine
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
| | - Xiaoyan Cui
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
| | - Xin Chen
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
| | - Na Ma
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
| | - Pradeep Kachroo
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
| | - Haijan Zhi
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
| | - Aardra Kachroo
- National Center for Soybean Improvement, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China (H.L., N.M., H.Z.);Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546 (H.L., M.B.S., P.K., A.K.); andJiangsu Academy of Agricultural Sciences, Nanjing 210014, China (X.Cu., X.Ch.)
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Wu X, Gong F, Wang W. Functional assignment to maize group 1 LEA protein EMB564 within the cell nucleus using computational analysis. Bioinformation 2013; 9:276-80. [PMID: 23559745 PMCID: PMC3607185 DOI: 10.6026/97320630009276] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 02/23/2013] [Indexed: 11/23/2022] Open
Abstract
Maize protein EMB564 is a member of group 1 LEA (late embryogenesis abundant) proteins. Currently, the molecular functions of
group 1 LEA proteins remain largely unclear. We here report on the functional assignment to EMB564 by computational analysis.
EMB564 is predicted as nuclear localization by five different predictors including CELLO, Plant-mPLoc, WoLF PSORT, Predotar
and TargetP. EMB564 is found to be remote homologous with DNA/RNA helicases and single-stranded DNA-binding proteins,
and their sequences contains similar DNA/RNA binding sites. Furthermore, the three-dimensional (3D) model of EMB564
structurally resembles a variety of nuclear and DNA/RNA-binding proteins, especially those involving in the regulation of cell
division, chromosomal replication and DNA unwinding or repairing. Our results reveal that EMB564 protein is most likely to
function within the cell nucleus.
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Affiliation(s)
- Xiaolin Wu
- Key Laboratory of Physiological Ecology & Genetic Improvement of Food Crops in Henan Province, College of Life Science, Henan Agricultural University, Zhengzhou 450002, China
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Anderson G, Wang R, Bandyopadhyay A, Goodin M. The Nucleocapsid Protein of Potato Yellow dwarf Virus: Protein Interactions and Nuclear Import Mediated by a Non-Canonical Nuclear Localization Signal. FRONTIERS IN PLANT SCIENCE 2012; 3:14. [PMID: 22645569 PMCID: PMC3355789 DOI: 10.3389/fpls.2012.00014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 01/15/2012] [Indexed: 05/12/2023]
Abstract
Potato yellow dwarf virus (PYDV) is the type species of the genus Nucleorhabdovirus and, like all members of this genus, replication and morphogenesis occurs inside the nuclei of infected cells. Protein localization prediction algorithms failed to identify a nuclear localization signal (NLS) in PYDV nucleocapsid (N) protein, although PYDV-N has been shown to localize exclusively to the nucleus when expressed as a green fluorescent protein (GFP):N fusion in plant cells. Deletion analysis using fragments of PYDV-N identified a karyophilic region in the carboxy-terminal 122 amino acids. Alanine-scanning mutagenesis was performed across this region in the context of the full-length N protein. Mutants were assayed for their ability to nuclear localize using live-cell imaging and a yeast-based assay. Two amino acid motifs, (419)QKR(421) and (432)KR(433) were shown to be essential for nuclear import and interaction with importin-α. Additional bimolecular fluorescence complementation showed that the PYDV-N-NLS mutants cannot be ferried into the nucleus via interaction with PYDV-P or -M. In contrast, interaction with N-NLS mutants appeared to retard the nuclear import of PYDV-P. GFP fused to aa 419-434 established that the PYDV-N-NLS can function outside the context of this protein. Taken together, it was determined that PYDV-N contains the bipartite NLS (419)QKRANEEAPPAAQKR(433).
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Affiliation(s)
- Gavin Anderson
- Department of Plant Pathology, University of KentuckyLexington, KY, USA
| | - Renyuan Wang
- Department of Plant Pathology, University of KentuckyLexington, KY, USA
| | | | - Michael Goodin
- Department of Plant Pathology, University of KentuckyLexington, KY, USA
- *Correspondence: Michael Goodin, Department of Plant Pathology, University of Kentucky, 201F Plant Sciences Building, Lexington, KY 40546, USA. e-mail:
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Cho EJ, Yuen CY, Kang BH, Ondzighi CA, Staehelin LA, Christopher DA. Protein disulfide isomerase-2 of Arabidopsis mediates protein folding and localizes to both the secretory pathway and nucleus, where it interacts with maternal effect embryo arrest factor. Mol Cells 2011; 32:459-75. [PMID: 21909944 PMCID: PMC3887692 DOI: 10.1007/s10059-011-0150-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 08/13/2011] [Accepted: 08/16/2011] [Indexed: 12/16/2022] Open
Abstract
Protein disulfide isomerase (PDI) is a thiodisulfide oxidoreductase that catalyzes the formation, reduction and rearrangement of disulfide bonds in proteins of eukaryotes. The classical PDI has a signal peptide, two CXXC-containing thioredoxin catalytic sites (a,a'), two noncatalytic thioredoxin fold domains (b,b'), an acidic domain (c) and a C-terminal endoplasmic reticulum (ER) retention signal. Although PDI resides in the ER where it mediates the folding of nascent polypeptides of the secretory pathway, we recently showed that PDI5 of Arabidopsis thaliana chaperones and inhibits cysteine proteases during trafficking to vacuoles prior to programmed cell death of the endothelium in developing seeds. Here we describe Arabidopsis PDI2, which shares a primary structure similar to that of classical PDI. Recombinant PDI2 is imported into ER-derived microsomes and complements the E. coli protein-folding mutant, dsbA. PDI2 interacted with proteins in both the ER and nucleus, including ER-resident protein folding chaperone, BiP1, and nuclear embryo transcription factor, MEE8. The PDI2-MEE8 interaction was confirmed to occur in vitro and in vivo. Transient expression of PDI2-GFP fusions in mesophyll protoplasts resulted in labeling of the ER, nucleus and vacuole. PDI2 is expressed in multiple tissues, with relatively high expression in seeds and root tips. Immunoelectron microscopy with GFP- and PDI2-specific antisera on transgenic seeds (PDI2-GFP) and wild type roots demonstrated that PDI2 was found in the secretory pathway (ER, Golgi, vacuole, cell wall) and the nuclei. Our results indicate that PDI2 mediates protein folding in the ER and has new functional roles in the nucleus.
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Affiliation(s)
| | | | - Byung-Ho Kang
- Department of Microbiology and Cell Science, University of Florida, USA
| | - Christine A. Ondzighi
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, USA
| | - L. Andrew Staehelin
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, USA
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Min BE, Martin K, Wang R, Tafelmeyer P, Bridges M, Goodin M. A host-factor interaction and localization map for a plant-adapted rhabdovirus implicates cytoplasm-tethered transcription activators in cell-to-cell movement. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:1420-32. [PMID: 20923350 DOI: 10.1094/mpmi-04-10-0097] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
To identify host factors that play critical roles in processes, including cell-to-cell movement of plant-adapted rhabdoviruses, we constructed and validated a high-resolution Nicotiana benthamiana yeast two-hybrid library. The library was screened with the putative movement protein (sc4), nucleocapsid (N), and matrix (M) proteins of Sonchus yellow net virus (SYNV). This resulted in identification of 31 potential host factors. Steady-state localization studies using autofluorescent protein fusions to full-length clones of interactors were conducted in transgenic N. benthamiana marker lines. Bimolecular fluorescence complementation assays were used to validate two-hybrid interactions. The sc4 interactor, sc4i21, localized to microtubules. The N interactor, Ni67, localized to punctuate loci on the endoplasmic reticulum. These two proteins are 84% identical homologues of the Arabidopsis phloem-associated transcription activator AtVOZ1, and contain functional nuclear localization signals. Sc4i17 is a microtubule-associated motor protein. The M interactor, Mi7, is a nuclear-localized transcription factor. Combined with a binary interaction map for SYNV proteins, our data support a model in which the SYNV nucleocapsids are exported from the nucleus and moved cell-to-cell by transcription activators tethered in the cytoplasm.
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Affiliation(s)
- Byoung-Eun Min
- Department of Plant Pathology, University of Kentucky, Lexington 40546, USA
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Bandyopadhyay A, Kopperud K, Anderson G, Martin K, Goodin M. An integrated protein localization and interaction map for Potato yellow dwarf virus, type species of the genus Nucleorhabdovirus. Virology 2010; 402:61-71. [PMID: 20362316 PMCID: PMC2873121 DOI: 10.1016/j.virol.2010.03.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 02/13/2010] [Accepted: 03/05/2010] [Indexed: 01/15/2023]
Abstract
The genome of Potato yellow dwarf virus (PYDV; Nucleorhabdovirus type species) was determined to be 12,875 nucleotides (nt). The antigenome is organized into seven open reading frames (ORFs) ordered 3'-N-X-P-Y-M-G-L-5', which likely encode the nucleocapsid, phospho, movement, matrix, glyco and RNA-dependent RNA polymerase proteins, respectively, except for X, which is of unknown function. The ORFs are flanked by a 3' leader RNA of 149 nt and a 5' trailer RNA of 97 nt, and are separated by conserved intergenic junctions. Phylogenetic analyses indicated that PYDV is closely related to other leafhopper-transmitted rhabdoviruses. Functional protein assays were used to determine the subcellular localization of PYDV proteins. Surprisingly, the M protein was able to induce the intranuclear accumulation of the inner nuclear membrane in the absence of any other viral protein. Finally, bimolecular fluorescence complementation was used to generate the most comprehensive protein interaction map for a plant-adapted rhabdovirus to date.
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