1
|
Zeng L, Gomez Mendez MF, Guo J, Jiang J, Zhang B, Chen H, Le B, Ke H, Dehesh K. Activation of stress-response genes by retrograde signaling-mediated destabilization of nuclear importin IMPα-9 and its interactor TPR2. MOLECULAR PLANT 2024; 17:884-899. [PMID: 38693693 DOI: 10.1016/j.molp.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/26/2024] [Accepted: 04/21/2024] [Indexed: 05/03/2024]
Abstract
Stress-induced retrograde signal transmission from the plastids to the nucleus has long puzzled plant biologists. To address this, we performed a suppressor screen of the ceh1 mutant, which contains elevated 2-C-methyl-d-erythritol-2,4-cyclopyrophosphate (MEcPP) levels, and identified the gain-of-function mutant impα-9, which shows reversed dwarfism and suppressed expression of stress-response genes in the ceh1 background despite heightened MEcPP. Subsequent genetic and biochemical analyses established that the accumulation of MEcPP initiates an upsurge in Arabidopsis SKP1-like 1 (ASK1) abundance, a pivotal component in the proteasome degradation pathway. This increase in ASK1 prompts the degradation of IMPα-9. Moreover, we uncovered a protein-protein interaction between IMPα-9 and TPR2, a transcriptional co-suppressor and found that a reduction in IMPα-9 levels coincides with a decrease in TPR2 abundance. Significantly, the interaction between IMPα-9 and TPR2 was disrupted in impα-9 mutants, highlighting the critical role of a single amino acid alteration in maintaining their association. Disruption of their interaction results in the reversal of MEcPP-associated phenotypes. Chromatin immunoprecipitation coupled with sequencing analyses revealed that TPR2 binds globally to stress-response genes and suggested that IMPα-9 associates with the chromatin. They function together to suppress the expression of stress-response genes under normal conditions, but this suppression is alleviated in response to stress through the degradation of the suppressing machinery. The biological relevance of our discoveries was validated under high light stress, marked by MEcPP accumulation, elevated ASK1 levels, IMPα-9 degredation, reduced TPR2 abundance, and subsequent activation of a network of stress-response genes. In summary, our study collectively unveils fresh insights into plant adaptive mechanisms, highlighting intricate interactions among retrograde signaling, the proteasome, and nuclear transport machinery.
Collapse
Affiliation(s)
- Liping Zeng
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Maria Fernanda Gomez Mendez
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Jingzhe Guo
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Jishan Jiang
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Bailong Zhang
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA; School of Medicine, University of California, Riverside, Riverside, CA 92521, USA
| | - Hao Chen
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Brandon Le
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Haiyan Ke
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Katayoon Dehesh
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA.
| |
Collapse
|
2
|
Tessier TM, King CR, Mymryk JS. Exploiting the endogenous yeast nuclear proteome to identify short linear motifs in vivo. CELL REPORTS METHODS 2023; 3:100637. [PMID: 37949066 PMCID: PMC10694487 DOI: 10.1016/j.crmeth.2023.100637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/01/2023] [Accepted: 10/17/2023] [Indexed: 11/12/2023]
Abstract
Peptide-domain interactions mediated by short linear motifs (SLiMs) play crucial roles in cellular biology. The simplicity of SLiMs poses challenges in their computational identification. Existing high-throughput methods for discovering SLiMs lack cellular context as they are typically performed in vitro. We developed a functional selection method using yeast to identify peptides that interact with the endogenous yeast nuclear proteome. Remarkably, peptides selected for in yeast also mediated nuclear import in human cells. Notably, the identified peptides did not resemble classical nuclear localization sequences. This platform has the potential to identify and investigate motifs that interact with the nuclear proteome of yeast and human and to aid in the identification and understanding of alternative protein nuclear import mechanisms.
Collapse
Affiliation(s)
- Tanner M Tessier
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Cason R King
- Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Joe S Mymryk
- Department of Microbiology and Immunology, Western University, London, ON, Canada; Department of Oncology, Western University, London, ON, Canada; Department of Otolaryngology, Western University, London, ON, Canada; London Regional Cancer Program, Lawson Health Research Institute, London, ON, Canada.
| |
Collapse
|
3
|
Ao K, Rohmann PFW, Huang S, Li L, Lipka V, Chen S, Wiermer M, Li X. Puncta-localized TRAF domain protein TC1b contributes to the autoimmunity of snc1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:591-612. [PMID: 36799433 DOI: 10.1111/tpj.16155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 02/07/2023] [Indexed: 05/04/2023]
Abstract
Immune receptors play important roles in the perception of pathogens and initiation of immune responses in both plants and animals. Intracellular nucleotide-binding domain leucine-rich repeat (NLR)-type receptors constitute a major class of receptors in vascular plants. In the Arabidopsis thaliana mutant suppressor of npr1-1, constitutive 1 (snc1), a gain-of-function mutation in the NLR gene SNC1 leads to SNC1 overaccumulation and constitutive activation of defense responses. From a CRISPR/Cas9-based reverse genetics screen in the snc1 autoimmune background, we identified that mutations in TRAF CANDIDATE 1b (TC1b), a gene encoding a protein with four tumor necrosis factor receptor-associated factor (TRAF) domains, can suppress snc1 phenotypes. TC1b does not appear to be a general immune regulator as it is not required for defense mediated by other tested immune receptors. TC1b also does not physically associate with SNC1, affect SNC1 accumulation, or affect signaling of the downstream helper NLRs represented by ACTIVATED DISEASE RESISTANCE PROTEIN 1-L2 (ADR1-L2), suggesting that TC1b impacts snc1 autoimmunity in a unique way. TC1b can form oligomers and localizes to punctate structures of unknown function. The puncta localization of TC1b strictly requires its coiled-coil (CC) domain, whereas the functionality of TC1b requires the four TRAF domains in addition to the CC. Overall, we uncovered the TRAF domain protein TC1b as a novel positive contributor to plant immunity.
Collapse
Affiliation(s)
- Kevin Ao
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Philipp F W Rohmann
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077, Goettingen, Germany
- Biochemistry of Plant-Microbe Interactions, Dahlem Centre of Plant Sciences, Institute of Biology, Freie Universität Berlin, 14195, Berlin, Germany
| | - Shuai Huang
- Department of Molecular Genetics, College of Arts and Sciences, Ohio State University, Columbus, Ohio, 43210, USA
| | - Lin Li
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Volker Lipka
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077, Goettingen, Germany
- Central Microscopy Facility of the Faculty of Biology and Psychology, University of Goettingen, D-37077, Goettingen, Germany
| | - She Chen
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Marcel Wiermer
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, D-37077, Goettingen, Germany
- Biochemistry of Plant-Microbe Interactions, Dahlem Centre of Plant Sciences, Institute of Biology, Freie Universität Berlin, 14195, Berlin, Germany
| | - Xin Li
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| |
Collapse
|
4
|
Lüdke D, Yan Q, Rohmann PFW, Wiermer M. NLR we there yet? Nucleocytoplasmic coordination of NLR-mediated immunity. THE NEW PHYTOLOGIST 2022; 236:24-42. [PMID: 35794845 DOI: 10.1111/nph.18359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
Plant intracellular nucleotide-binding leucine-rich repeat immune receptors (NLRs) perceive the activity of pathogen-secreted effector molecules that, when undetected, promote colonisation of hosts. Signalling from activated NLRs converges with and potentiates downstream responses from activated pattern recognition receptors (PRRs) that sense microbial signatures at the cell surface. Efficient signalling of both receptor branches relies on the host cell nucleus as an integration point for transcriptional reprogramming, and on the macromolecular transport processes that mediate the communication between cytoplasm and nucleoplasm. Studies on nuclear pore complexes (NPCs), the nucleoporin proteins (NUPs) that compose NPCs, and nuclear transport machinery constituents that control nucleocytoplasmic transport, have revealed that they play important roles in regulating plant immune responses. Here, we discuss the contributions of nucleoporins and nuclear transport receptor (NTR)-mediated signal transduction in plant immunity with an emphasis on NLR immune signalling across the nuclear compartment boundary and within the nucleus. We also highlight and discuss cytoplasmic and nuclear functions of NLRs and their signalling partners and further consider the potential implications of NLR activation and resistosome formation in both cellular compartments for mediating plant pathogen resistance and programmed host cell death.
Collapse
Affiliation(s)
- Daniel Lüdke
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Qiqi Yan
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Philipp F W Rohmann
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Marcel Wiermer
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
- Biochemistry of Plant-Microbe Interactions, Dahlem Centre of Plant Sciences, Institute of Biology, Freie Universität Berlin, Königin-Luise-Str. 12-16, 14195, Berlin, Germany
| |
Collapse
|
5
|
Xu X, Wang H, Liu J, Han S, Lin M, Guo Z, Chen X. OsWRKY62 and OsWRKY76 Interact with Importin α1s for Negative Regulation of Defensive Responses in Rice Nucleus. RICE (NEW YORK, N.Y.) 2022; 15:12. [PMID: 35184252 PMCID: PMC8859016 DOI: 10.1186/s12284-022-00558-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Background OsWRKY62 and OsWRKY76, two close members of WRKY transcription factors, function together as transcriptional repressors. OsWRKY62 is predominantly localized in the cytosol. What are the regulatory factors for OsWRKY62 nuclear translocation? Results In this study, we characterized the interaction of OsWRKY62 and OsWRKY76 with rice importin, OsIMα1a and OsIMα1b, for nuclear translocation. Chimeric OsWRKY62.1-GFP, which is predominantly localized in the cytoplasm, was translocated to the nucleus of Nicotiana benthamiana leaf cells in the presence of OsIMα1a or OsIMαΔIBB1a lacking the auto-inhibitory importin β-binding domain. OsIMαΔIBB1a interacted with the WRKY domain of OsWRKY62.1, which has specific bipartite positively charged concatenated amino acids functioning as a nuclear localization signal (NLS). Similarly, we found that OsIMαΔIBB1a interacted with the AvrPib effector of rice blast fungus Magnaporthe oryzae, which contains a scattered distribution of positively charged amino acids. Furthermore, we identified a nuclear export signal (NES) in OsWRKY62.1 that inhibited nuclear transportation. Overexpression of OsIMα1a or OsIMα1b enhanced resistance to M. oryzae, whereas knockout mutants decreased resistance to the pathogen. However, overexpressing both OsIMα1a and OsWRKY62.1 were slightly more susceptible to M. oryzae than OsWRKY62.1 alone. Ectopic overexpression of OsWRKY62.1-NES fused gene compromised the enhanced susceptibility of OsWRKY62.1 to M. oryzae. Conclusion These results revealed the existence of NLS and NES in OsWRKY62. OsWRKY62, OsWRKY76, and AvrPib effector translocate to nucleus in association with importin α1s through new types of nuclear localization signals for negatively regulating defense responses.
Collapse
Affiliation(s)
- Xiaohui Xu
- Key Laboratory of Pest Monitoring and Green Management, MOA, Joint Laboratory for International Cooperation in Crop Molecular Breeding; Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
- College of Modern Science and Technology, China Jiliang University, Hangzhou, 310018 China
| | - Han Wang
- Key Laboratory of Pest Monitoring and Green Management, MOA, Joint Laboratory for International Cooperation in Crop Molecular Breeding; Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| | - Jiqin Liu
- Key Laboratory of Pest Monitoring and Green Management, MOA, Joint Laboratory for International Cooperation in Crop Molecular Breeding; Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| | - Shuying Han
- Key Laboratory of Pest Monitoring and Green Management, MOA, Joint Laboratory for International Cooperation in Crop Molecular Breeding; Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| | - Miaomiao Lin
- Key Laboratory of Pest Monitoring and Green Management, MOA, Joint Laboratory for International Cooperation in Crop Molecular Breeding; Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| | - Zejian Guo
- Key Laboratory of Pest Monitoring and Green Management, MOA, Joint Laboratory for International Cooperation in Crop Molecular Breeding; Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| | - Xujun Chen
- Key Laboratory of Pest Monitoring and Green Management, MOA, Joint Laboratory for International Cooperation in Crop Molecular Breeding; Department of Plant Pathology, China Agricultural University, Beijing, 100193 China
| |
Collapse
|
6
|
Tsimbalyuk S, Donnelly CM, Forwood JK. Structural characterization of human importin alpha 7 in its cargo-free form at 2.5 Å resolution. Sci Rep 2022; 12:315. [PMID: 35013395 PMCID: PMC8748863 DOI: 10.1038/s41598-021-03729-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/24/2021] [Indexed: 11/22/2022] Open
Abstract
Shuttling of macromolecules between nucleus and cytoplasm is a tightly regulated process mediated through specific interactions between cargo and nuclear transport proteins. In the classical nuclear import pathway, importin alpha recognizes cargo exhibiting a nuclear localization signal, and this complex is transported through the nuclear pore complex by importin beta. Humans possess seven importin alpha isoforms that can be grouped into three subfamilies, with many cargoes displaying specificity towards these importin alpha isoforms. The cargo binding sites within importin alpha isoforms are highly conserved in sequence, suggesting that specificity potentially relies on structural differences. Structures of some importin alpha isoforms, both in cargo-bound and free states, have been previously solved. However, there are currently no known structures of cargo free importin alpha isoforms within subfamily 3 (importin alpha 5, 6, 7). Here, we present the first crystal structure of human importin alpha 7 lacking the IBB domain solved at 2.5 Å resolution. The structure reveals a typical importin alpha architecture comprised of ten armadillo repeats and is most structurally conserved with importin alpha 5. Very little difference in structure was observed between the cargo-bound and free states, implying that importin alpha 7 does not undergo conformational change when binding cargo. These structural insights provide a strong platform for further evaluation of structure–function relationships and understanding how isoform specificity within the importin alpha family plays a role in nuclear transport in health and disease.
Collapse
Affiliation(s)
- S Tsimbalyuk
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia
| | - C M Donnelly
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia
| | - J K Forwood
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia. .,School of Dentistry and Medical Sciences, Charles Sturt University, Room 2, National Life Sciences Hub, Wagga Wagga, NSW, 2678, Australia.
| |
Collapse
|
7
|
Ao K, Tong M, Li L, Lüdke D, Lipka V, Chen S, Wiermer M, Li X. SCF SNIPER7 controls protein turnover of unfoldase CDC48A to promote plant immunity. THE NEW PHYTOLOGIST 2021; 229:2795-2811. [PMID: 33156518 DOI: 10.1111/nph.17071] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 11/01/2020] [Indexed: 06/11/2023]
Abstract
The unfoldase CDC48 (Cell Division Cycle 48) is highly conserved in eukaryotes, serving as an AAA + ATPase to extract ubiquitinated proteins from large protein complexes and membranes. Although its biochemical properties have been studied extensively in yeast and animal systems, the biological roles and regulations of the plant CDC48s have been explored only recently. Here we describe the identification of a novel E3 ligase from the SNIPER (snc1-influencing plant E3 ligase reverse genetic) screen, which contributes to plant defense regulation by targeting CDC48A for degradation. SNIPER7 encodes an F-box protein and its overexpression leads to autoimmunity. We identified CDC48s as interactors of SNIPER7 through immunoprecipitation followed by mass spectrometry proteomic analysis. SNIPER7 overexpression lines phenocopy the autoimmune mutant Atcdc48a-4. Furthermore, CDC48A protein levels are reduced or stabilized when SNIPER7 is overexpressed or inhibited, respectively, suggesting that CDC48A is the ubiquitination substrate of SCFSNIPER7 . Taken together, this study reveals a new mechanism where a SCFSNIPER7 complex regulates CDC48 unfoldase levels and modulates immune output.
Collapse
Affiliation(s)
- Kevin Ao
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Meixuezi Tong
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Lin Li
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Daniel Lüdke
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, D-37077, Germany
| | - Volker Lipka
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, D-37077, Germany
- Central Microscopy Facility of the Faculty of Biology and Psychology, University of Goettingen, Goettingen, D-37077, Germany
| | - She Chen
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Marcel Wiermer
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, D-37077, Germany
| | - Xin Li
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| |
Collapse
|
8
|
Lüdke D, Roth C, Kamrad SA, Messerschmidt J, Hartken D, Appel J, Hörnich BF, Yan Q, Kusch S, Klenke M, Gunkel A, Wirthmueller L, Wiermer M. Functional requirement of the Arabidopsis importin-α nuclear transport receptor family in autoimmunity mediated by the NLR protein SNC1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:994-1009. [PMID: 33210758 DOI: 10.1111/tpj.15082] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/03/2020] [Accepted: 11/11/2020] [Indexed: 05/28/2023]
Abstract
IMPORTIN-α3/MOS6 (MODIFIER OF SNC1, 6) is one of nine importin-α isoforms in Arabidopsis that recruit nuclear localization signal-containing cargo proteins to the nuclear import machinery. IMP-α3/MOS6 is required genetically for full autoimmunity of the nucleotide-binding leucine-rich repeat immune receptor mutant snc1 (suppressor of npr1-1, constitutive 1) and MOS6 also contributes to basal disease resistance. Here, we investigated the contribution of the other importin-α genes to both types of immune responses, and we analyzed potential interactions of all importin-α isoforms with SNC1. By using reverse-genetic analyses in Arabidopsis and protein-protein interaction assays in Nicotiana benthamiana, we provide evidence that among the nine α-importins in Arabidopsis, IMP-α3/MOS6 is the main nuclear transport receptor of SNC1, and that IMP-α3/MOS6 is required selectively for autoimmunity of snc1 and basal resistance to mildly virulent Pseudomonas syringae in Arabidopsis.
Collapse
Affiliation(s)
- Daniel Lüdke
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Charlotte Roth
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Sieglinde A Kamrad
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Jana Messerschmidt
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Denise Hartken
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Jonas Appel
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Bojan F Hörnich
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Qiqi Yan
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Stefan Kusch
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Melanie Klenke
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Annette Gunkel
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Lennart Wirthmueller
- Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany
| | - Marcel Wiermer
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
- Molecular Biology of Plant-Microbe Interactions Research Group, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37077, Goettingen, Germany
| |
Collapse
|
9
|
Lüdke D, Rohmann PFW, Wiermer M. Nucleocytoplasmic Communication in Healthy and Diseased Plant Tissues. FRONTIERS IN PLANT SCIENCE 2021; 12:719453. [PMID: 34394173 PMCID: PMC8357054 DOI: 10.3389/fpls.2021.719453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/09/2021] [Indexed: 05/16/2023]
Abstract
The double membrane of the nuclear envelope (NE) constitutes a selective compartment barrier that separates nuclear from cytoplasmic processes. Plant viability and responses to a changing environment depend on the spatial communication between both compartments. This communication is based on the bidirectional exchange of proteins and RNAs and is regulated by a sophisticated transport machinery. Macromolecular traffic across the NE depends on nuclear transport receptors (NTRs) that mediate nuclear import (i.e. importins) or export (i.e. exportins), as well as on nuclear pore complexes (NPCs) that are composed of nucleoporin proteins (NUPs) and span the NE. In this review, we provide an overview of plant NPC- and NTR-directed cargo transport and we consider transport independent functions of NPCs and NE-associated proteins in regulating plant developmental processes and responses to environmental stresses.
Collapse
Affiliation(s)
- Daniel Lüdke
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Philipp F. W. Rohmann
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Marcel Wiermer
- Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
- Molecular Biology of Plant-Microbe Interactions Research Group, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
- *Correspondence: Marcel Wiermer,
| |
Collapse
|
10
|
Li X, Gu Y. Structural and functional insight into the nuclear pore complex and nuclear transport receptors in plant stress signaling. CURRENT OPINION IN PLANT BIOLOGY 2020; 58:60-68. [PMID: 33217650 DOI: 10.1016/j.pbi.2020.10.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Nuclear pore complexes (NPC) are highly conserved mega protein complexes that penetrate the double-layered nuclear membrane and form channels to allow bi-directional transport of macromolecules between the nucleus and the cytosol. Non-passive nucleocytoplasmic transport also requires nuclear transport receptors (NTR), which bind cargo molecules and shuttle them across the NPC. The NPC and NTRs constitute two fundamental layers of regulatory mechanisms that together determine the selective nuclear translocation of signal molecules and play essential roles in activating the precise response of a cell to environmental stimuli. Here we discuss recent findings in the NPC made by advanced structural biology approaches, and dissect distinct functions of different NPC components and NTRs in plants' responses to various biotic and abiotic stresses.
Collapse
Affiliation(s)
- Xin Li
- Department of Plant and Microbial Biology, University of California, Berkeley, USA; Innovative Genomics Institute, University of California, Berkeley, USA
| | - Yangnan Gu
- Department of Plant and Microbial Biology, University of California, Berkeley, USA; Innovative Genomics Institute, University of California, Berkeley, USA.
| |
Collapse
|
11
|
Chen C, Kim D, Yun HR, Lee YM, Yogendra B, Bo Z, Kim HE, Min JH, Lee YS, Rim YG, Kim HU, Sung S, Heo JB. Nuclear import of LIKE HETEROCHROMATIN PROTEIN1 is redundantly mediated by importins α-1, α-2 and α-3. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1205-1214. [PMID: 32365248 PMCID: PMC7810169 DOI: 10.1111/tpj.14796] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 04/09/2020] [Accepted: 04/24/2020] [Indexed: 05/19/2023]
Abstract
LIKE HETEROCHROMATIN PROTEIN1 (LHP1) encodes the only plant homologue of the metazoan HETEROCHROMATIN PROTEIN1 (HP1) protein family. The LHP1 protein is necessary for proper epigenetic regulation of a range of developmental processes in plants. LHP1 is a transcriptional repressor of flowering-related genes, such as FLOWERING LOCUS T (FT), FLOWERING LOCUS C (FLC), AGAMOUS (AG) and APETALA 3 (AP3). We found that LHP1 interacts with importin α-1 (IMPα-1), importin α-2 (IMPα-2) and importin α-3 (IMPα-3) both in vitro and in vivo. A genetic approach revealed that triple mutation of impα-1, impα-2 and impα-3 resulted in Arabidopsis plants with a rapid flowering phenotype similar to that of plants with mutations in lhp1 due to the upregulation of FT expression. Nuclear targeting of LHP1 was severely impaired in the impα triple mutant, resulting in the de-repression of LHP1 target genes AG, AP3 and SHATTERPROOF 1 as well as FT. Therefore, the importin proteins IMPα-1, -2 and -3 are necessary for the nuclear import of LHP1.
Collapse
Affiliation(s)
- Chong Chen
- Department of Molecular Genetic Biotechnology, Dong-A University, Busan 604-714, Korea
| | - Daewon Kim
- Department of Biotechnology, Dong-A University, Busan 604-714, Korea
| | - Hee Rang Yun
- Department of Molecular Genetic Biotechnology, Dong-A University, Busan 604-714, Korea
| | - Yun Mi Lee
- Department of Molecular Genetic Biotechnology, Dong-A University, Busan 604-714, Korea
| | - Bordiya Yogendra
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA
| | - Zhao Bo
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA
| | - Hae Eun Kim
- Department of Molecular Genetic Biotechnology, Dong-A University, Busan 604-714, Korea
| | - Jun Hong Min
- Department of Molecular Genetic Biotechnology, Dong-A University, Busan 604-714, Korea
| | - Yong-Suk Lee
- Department of Biotechnology, Dong-A University, Busan 604-714, Korea
| | - Yeong Gil Rim
- Systems & Synthetic Agrobiotech Center, Gyeongsang National University, Jinju 660-701 Korea
| | - Hyun Uk Kim
- Department of Bioindustry and Bioresource Engineering, Sejong University, Seoul, 05006 Korea
| | - Sibum Sung
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA
- International Scholar, Kyung-Hee University, Suwon, Korea
- Corresponding author: Tel: +82 51 200 7520; Fax: +82 51 200 7505. ;
| | - Jae Bok Heo
- Department of Molecular Genetic Biotechnology, Dong-A University, Busan 604-714, Korea
- Corresponding author: Tel: +82 51 200 7520; Fax: +82 51 200 7505. ;
| |
Collapse
|
12
|
Zhang A, Wang S, Kim J, Yan J, Yan X, Pang Q, Hua J. Nuclear pore complex components have temperature-influenced roles in plant growth and immunity. PLANT, CELL & ENVIRONMENT 2020; 43:1452-1466. [PMID: 32022936 DOI: 10.1111/pce.13741] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 01/19/2020] [Accepted: 02/01/2020] [Indexed: 05/28/2023]
Abstract
Nuclear pore complexes (NPCs) are main channels controlling nucleocytoplasmic transport and are composed of approximately 30 nucleoporins (NUPs). Emerging evidence suggests that some NUP genes have specialized functions that challenge the traditional view of NPCs as structures of uniform composition. Here, we analysed the role of six outer-ring components of NPC at normal and warm growth temperatures by examining their loss-of-function mutants in Arabidopsis thaliana. All six NUP subunits, NUP85, NUP96, NUP 133, NUP 160, SEH1 and HOS1, have a non-redundant temperature-influenced function in one or more of the processes, including rosette growth, leaf architecture and intracellular immune receptor-mediated disease resistance. At the molecular level, NUP85 and NUP133 are required for mRNA export only at warm temperature and play a larger role in the localization of transcription factor at warm temperature. In addition, NUP96 and HOS1 are essential for the expression of high temperature-responsive genes, which is correlated with their larger activity in facilitating nuclear accumulation of the transcription factor PIF4 at warm temperature. Our results show that subunits of NPC have differential roles at different temperatures, suggesting the existence of temperature-influenced NPC complexes and activities.
Collapse
Affiliation(s)
- Aiqin Zhang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, China
- School of Integrated Plant Science, Plant Biology Section, Cornell University, Ithaca, New York
| | - Shuai Wang
- School of Integrated Plant Science, Plant Biology Section, Cornell University, Ithaca, New York
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Jitae Kim
- School of Integrated Plant Science, Plant Biology Section, Cornell University, Ithaca, New York
| | - Jiapei Yan
- School of Integrated Plant Science, Plant Biology Section, Cornell University, Ithaca, New York
| | - Xiufeng Yan
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Qiuying Pang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Jian Hua
- School of Integrated Plant Science, Plant Biology Section, Cornell University, Ithaca, New York
| |
Collapse
|
13
|
Contreras R, Kallemi P, González-García MP, Lazarova A, Sánchez-Serrano JJ, Sanmartín M, Rojo E. Identification of Domains and Factors Involved in MINIYO Nuclear Import. FRONTIERS IN PLANT SCIENCE 2019; 10:1044. [PMID: 31552063 PMCID: PMC6748027 DOI: 10.3389/fpls.2019.01044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/29/2019] [Indexed: 05/28/2023]
Abstract
The transition of stem cells from self-renewal into differentiation is tightly regulated to assure proper development of the organism. Arabidopsis MINIYO (IYO) and its mammalian orthologue RNA polymerase II associated protein 1 (RPAP1) are essential factors for initiating stem cell differentiation in plants and animals. Moreover, there is evidence suggesting that the translocation of IYO and RPAP1 from the cytosol into the nucleus functions as a molecular switch to initiate this cell fate transition. Identifying the determinants of IYO subcellular localization would allow testing if, indeed, nuclear IYO migration triggers cell differentiation and could provide tools to control this crucial developmental transition. Through transient and stable expression assays in Nicotiana benthamiana and Arabidopsis thaliana, we demonstrate that IYO contains two nuclear localization signals (NLSs), located at the N- and C-terminus of the protein, which mediate the interaction with the NLS-receptor IMPA4 and the import of the protein into the nucleus. Interestingly, IYO also interacts with GPN GTPases, which are involved in selective nuclear import of RNA polymerase II. This interaction is prevented when the G1 motif in GPN1 is mutated, suggesting that IYO binds specifically to the nucleotide-bound form of GPN1. In contrast, deleting the NLSs in IYO does not prevent the interaction with GPN1, but it interferes with import of GPN1 into the nucleus, indicating that IYO and GPN1 are co-transported as a complex that requires the IYO NLSs for import. This work unveils key domains and factors involved in IYO nuclear import, which may prove instrumental to determine how IYO and RPAP1 control stem cell differentiation.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Enrique Rojo
- *Correspondence: Maite Sanmartín, , ; Enrique Rojo,
| |
Collapse
|
14
|
Helizon H, Rösler-Dalton J, Gasch P, von Horsten S, Essen LO, Zeidler M. Arabidopsis phytochrome A nuclear translocation is mediated by a far-red elongated hypocotyl 1-importin complex. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:1255-1268. [PMID: 30256472 DOI: 10.1111/tpj.14107] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 09/19/2018] [Indexed: 05/28/2023]
Abstract
Phytochrome A (phyA) is a red and far-red (FR) sensing photoreceptor regulating plant growth and development. Its biologically active FR-absorbing form Pfr translocates into the nucleus and subsequently regulates gene expression. Two transport facilitators, FR elongated hypocotyl 1 (FHY1) and FHY1-like (FHL), are crucial for its cytoplasmic-nuclear translocation. FHY1 interacts preferentially with activated phyA (Pfr) in assays with recombinant phyA and FHY1 and in vivo. Nuclear translocation of the phyA-FHY1 complex depends on a nuclear localization signal (NLS) of FHY1, which is recognized by IMPαs independently of phyA. The complex is guided along the actin cytoskeleton. Additionally, FHY1 has the ability to exit the nucleus via the exportin route, thus is able to repeatedly transport phyA molecules to the nucleus, balancing the nucleo-cytoplasmic distribution. The direction of FHY1s transport appears to depend on its phosphorylation state in different compartments. Phosphorylated serins close to the NLS prevent FHY1 binding to IMPα. The work presented here elucidates key steps of the mechanism by which photoactivated phyA translocates to the nucleus.
Collapse
Affiliation(s)
- Hanna Helizon
- Institute for Plant Physiology, University Giessen, 35390, Giessen, Germany
| | - Jutta Rösler-Dalton
- Department of Plant Biology, University of California, Berkeley, CA, 94720, USA
| | - Philipp Gasch
- Plant Physiology, University Bayreuth, 95447, Bayreuth, Germany
| | - Silke von Horsten
- Department of Chemistry, University Marburg, 35032, Marburg, Germany
| | - Lars-Oliver Essen
- Department of Chemistry, University Marburg, 35032, Marburg, Germany
| | - Mathias Zeidler
- Institute for Plant Physiology, University Giessen, 35390, Giessen, Germany
| |
Collapse
|
15
|
Chen C, Masi RD, Lintermann R, Wirthmueller L. Nuclear Import of Arabidopsis Poly(ADP-Ribose) Polymerase 2 Is Mediated by Importin-α and a Nuclear Localization Sequence Located Between the Predicted SAP Domains. FRONTIERS IN PLANT SCIENCE 2018; 9:1581. [PMID: 30455710 PMCID: PMC6230994 DOI: 10.3389/fpls.2018.01581] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 10/10/2018] [Indexed: 05/17/2023]
Abstract
Proteins of the Poly(ADP-Ribose) Polymerase (PARP) family modify target proteins by covalent attachment of ADP-ribose moieties onto amino acid side chains. In Arabidopsis, PARP proteins contribute to repair of DNA lesions and modulate plant responses to various abiotic and biotic stressors. Arabidopsis PARP1 and PARP2 are nuclear proteins and given that their molecular weights exceed the diffusion limit of nuclear pore complexes, an active import mechanism into the nucleus is likely. Here we use confocal microscopy of fluorescent protein-tagged Arabidopsis PARP2 and PARP2 deletion constructs in combination with site-directed mutagenesis to identify a nuclear localization sequence in PARP2 that is required for nuclear import. We report that in co-immunoprecipitation assays PARP2 interacts with several isoforms of the importin-α group of nuclear transport adapters and that PARP2 binding to IMPORTIN-α2 is mediated by the identified nuclear localization sequence. Our results demonstrate that PARP2 is a cargo protein of the canonical importin-α/β nuclear import pathway.
Collapse
Affiliation(s)
| | | | | | - Lennart Wirthmueller
- Department of Plant Biochemistry, Dahlem Centre of Plant Sciences, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
16
|
Kirby TW, Pedersen LC, Gabel SA, Gassman NR, London RE. Variations in nuclear localization strategies among pol X family enzymes. Traffic 2018; 19:10.1111/tra.12600. [PMID: 29931796 PMCID: PMC6684861 DOI: 10.1111/tra.12600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 12/22/2022]
Abstract
Despite the essential roles of pol X family enzymes in DNA repair, information about the structural basis of their nuclear import is limited. Recent studies revealed the unexpected presence of a functional nuclear localization signal (NLS) in DNA polymerase β, indicating the importance of active nuclear targeting, even for enzymes likely to leak into and out of the nucleus. The current studies further explore the active nuclear transport of these enzymes by identifying and structurally characterizing the functional NLS sequences in the three remaining human pol X enzymes: terminal deoxynucleotidyl transferase (TdT), DNA polymerase mu (pol μ) and DNA polymerase lambda (pol λ). NLS identifications are based on Importin α (Impα) binding affinity determined by fluorescence polarization of fluorescein-labeled NLS peptides, X-ray crystallographic analysis of the Impα∆IBB•NLS complexes and fluorescence-based subcellular localization studies. All three polymerases use NLS sequences located near their N-terminus; TdT and pol μ utilize monopartite NLS sequences, while pol λ utilizes a bipartite sequence, unique among the pol X family members. The pol μ NLS has relatively weak measured affinity for Impα, due in part to its proximity to the N-terminus that limits non-specific interactions of flanking residues preceding the NLS. However, this effect is partially mitigated by an N-terminal sequence unsupportive of Met1 removal by methionine aminopeptidase, leading to a 3-fold increase in affinity when the N-terminal methionine is present. Nuclear targeting is unique to each pol X family enzyme with variations dependent on the structure and unique functional role of each polymerase.
Collapse
Affiliation(s)
- Thomas W Kirby
- National Institute of Environmental Health Sciences, Genome Integrity and Structural Biology Laboratory, National Institutes of Health, Research Triangle Park, North Carolina
| | - Lars C Pedersen
- National Institute of Environmental Health Sciences, Genome Integrity and Structural Biology Laboratory, National Institutes of Health, Research Triangle Park, North Carolina
| | - Scott A Gabel
- National Institute of Environmental Health Sciences, Genome Integrity and Structural Biology Laboratory, National Institutes of Health, Research Triangle Park, North Carolina
| | - Natalie R Gassman
- Molecular & Metabolic Oncology, University of South Alabama Mitchell Cancer Institute, Mobile, Alabama
| | - Robert E London
- National Institute of Environmental Health Sciences, Genome Integrity and Structural Biology Laboratory, National Institutes of Health, Research Triangle Park, North Carolina
| |
Collapse
|
17
|
Lüdke D, Roth C, Hartken D, Wiermer M. MOS6 and TN13 in plant immunity. PLANT SIGNALING & BEHAVIOR 2018; 13:e1454816. [PMID: 29557707 PMCID: PMC5933908 DOI: 10.1080/15592324.2018.1454816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 03/16/2018] [Indexed: 06/08/2023]
Abstract
The Arabidopsis nuclear transport receptor IMPORTIN-α3/MOS6 (MODIFIER OF SNC1, 6) is required for constitutive defense responses of the auto-immune mutant snc1 (suppressor of npr1-1, constitutive 1) and contributes to basal disease resistance, suggesting a role in nuclear import of defense-regulatory cargo proteins. We recently showed that MOS6 selectively interacts with TN13, a TIR-NBS protein involved in basal resistance to Pseudomonas syringae pv. tomato (Pst) DC3000 lacking the effectors AvrPto and AvrPtoB. Consistent with a predicted N-terminal transmembrane domain, TN13 localizes to the endoplasmic reticulum (ER) and the nuclear envelope (NE) where it interacts with MOS6 in a transient expression assay. Here, we propose a model that summarizes the subcellular localization, association and function of TN13 and MOS6 in plant defense signaling.
Collapse
Affiliation(s)
- Daniel Lüdke
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, Goettingen, Germany
| | - Charlotte Roth
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, Goettingen, Germany
| | - Denise Hartken
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, Goettingen, Germany
| | - Marcel Wiermer
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, Goettingen, Germany
| |
Collapse
|
18
|
Robin GP, Kleemann J, Neumann U, Cabre L, Dallery JF, Lapalu N, O’Connell RJ. Subcellular Localization Screening of Colletotrichum higginsianum Effector Candidates Identifies Fungal Proteins Targeted to Plant Peroxisomes, Golgi Bodies, and Microtubules. FRONTIERS IN PLANT SCIENCE 2018; 9:562. [PMID: 29770142 PMCID: PMC5942036 DOI: 10.3389/fpls.2018.00562] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 04/10/2018] [Indexed: 05/20/2023]
Abstract
The genome of the hemibiotrophic anthracnose fungus, Colletotrichum higginsianum, encodes a large inventory of putative secreted effector proteins that are sequentially expressed at different stages of plant infection, namely appressorium-mediated penetration, biotrophy and necrotrophy. However, the destinations to which these proteins are addressed inside plant cells are unknown. In the present study, we selected 61 putative effector genes that are highly induced in appressoria and/or biotrophic hyphae. We then used Agrobacterium-mediated transformation to transiently express them as N-terminal fusions with fluorescent proteins in cells of Nicotiana benthamiana for imaging by confocal microscopy. Plant compartments labeled by the fusion proteins in N. benthamiana were validated by co-localization with specific organelle markers, by transient expression of the proteins in the true host plant, Arabidopsis thaliana, and by transmission electron microscopy-immunogold labeling. Among those proteins for which specific subcellular localizations could be verified, nine were imported into plant nuclei, three were imported into the matrix of peroxisomes, three decorated cortical microtubule arrays and one labeled Golgi stacks. Two peroxisome-targeted proteins harbored canonical C-terminal tripeptide signals for peroxisome import via the PTS1 (peroxisomal targeting signal 1) pathway, and we showed that these signals are essential for their peroxisome localization. Our findings provide valuable information about which host processes are potentially manipulated by this pathogen, and also reveal plant peroxisomes, microtubules, and Golgi as novel targets for fungal effectors.
Collapse
Affiliation(s)
- Guillaume P. Robin
- UMR BIOGER, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Jochen Kleemann
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Ulla Neumann
- Central Microscopy, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Lisa Cabre
- UMR BIOGER, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Jean-Félix Dallery
- UMR BIOGER, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Nicolas Lapalu
- UMR BIOGER, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Richard J. O’Connell
- UMR BIOGER, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Versailles, France
- *Correspondence: Richard J. O’Connell,
| |
Collapse
|
19
|
Gerth K, Lin F, Daamen F, Menzel W, Heinrich F, Heilmann M. Arabidopsis phosphatidylinositol 4-phosphate 5-kinase 2 contains a functional nuclear localization sequence and interacts with alpha-importins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:862-878. [PMID: 28949047 DOI: 10.1111/tpj.13724] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 08/22/2017] [Accepted: 09/11/2017] [Indexed: 05/22/2023]
Abstract
The Arabidopsis phosphoinositide kinase PIP5K2 has been implicated in the control of membrane trafficking and is important for development and growth. In addition to cytosolic functions of phosphoinositides, a nuclear phosphoinositide system has been proposed, but evidence for nuclear phosphoinositides in plants is limited. Fluorescence-tagged variants of PIP5K2 reside in the nucleus of Arabidopsis root meristem cells, in addition to reported plasma membrane localization. Here we report on the interaction of PIP5K2 with alpha-importins and characterize its nuclear localization sequences (NLSs). The PIP5K2 sequence contains four putative NLSs (NLSa-NLSd) and only a PIP5K2 fragment containing NLSs is imported into nuclei of onion epidermis cells upon transient expression. PIP5K2 interacts physically with alpha-importin isoforms in cytosolic split-ubiquitin-based yeast two-hybrid tests, in dot-blot experiments and in immuno-pull-downs. A 27-amino-acid fragment of PIP5K2 containing NLSc is necessary and sufficient to mediate the nuclear import of a large cargo fusion consisting of two mCherry markers fused to RubisCO large subunit. Substitution of basic residues in NLSc results in reduced import of PIP5K2 or other cargoes into plant nuclei. The data suggest that PIP5K2 is subject to active, alpha-importin-mediated nuclear import, consistent with a nuclear role for PIP5K2 in addition to its reported cytosolic functions. The detection of both substrate and product of PIP5K2 in plant nuclei according to reporter fluorescence and immunofluorescence further supports the notion of a nuclear phosphoinositide system in plants. Variants of PIP5K2 with reduced nuclear residence might serve as tools for the future functional study of plant nuclear phosphoinositides.
Collapse
Affiliation(s)
- Katharina Gerth
- Department of Cellular Biochemistry, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Feng Lin
- Department of Cellular Biochemistry, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Franziska Daamen
- Department of Cellular Biochemistry, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Wilhelm Menzel
- Department of Cellular Biochemistry, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Franziska Heinrich
- Department of Cellular Biochemistry, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Mareike Heilmann
- Department of Cellular Biochemistry, Institute of Biochemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle (Saale), Germany
| |
Collapse
|
20
|
Roth C, Lüdke D, Klenke M, Quathamer A, Valerius O, Braus GH, Wiermer M. The truncated NLR protein TIR-NBS13 is a MOS6/IMPORTIN-α3 interaction partner required for plant immunity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:808-821. [PMID: 28901644 DOI: 10.1111/tpj.13717] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 08/21/2017] [Accepted: 09/04/2017] [Indexed: 05/28/2023]
Abstract
Importin-α proteins mediate the translocation of nuclear localization signal (NLS)-containing proteins from the cytoplasm into the nucleus through nuclear pore complexes (NPCs). Genetically, Arabidopsis IMPORTIN-α3/MOS6 (MODIFIER OF SNC1, 6) is required for basal plant immunity and constitutive disease resistance activated in autoimmune mutant snc1 (suppressor of npr1-1, constitutive 1), suggesting that MOS6 plays a role in the nuclear import of proteins involved in plant defense signaling. Here, we sought to identify and characterize defense-regulatory cargo proteins and interaction partners of MOS6. We conducted both in silico database analyses and affinity purification of functional epitope-tagged MOS6 from pathogen-challenged stable transgenic plants coupled with mass spectrometry. We show that among the 13 candidate MOS6 interactors we selected for further functional characterization, the TIR-NBS-type protein TN13 is required for resistance against Pseudomonas syringae pv. tomato (Pst) DC3000 lacking the type-III effector proteins AvrPto and AvrPtoB. When expressed transiently in N. benthamiana leaves, TN13 co-immunoprecipitates with MOS6, but not with its closest homolog IMPORTIN-α6, and localizes to the endoplasmic reticulum (ER), consistent with a predicted N-terminal transmembrane domain in TN13. Our work uncovered the truncated NLR protein TN13 as a component of plant innate immunity that selectively binds to MOS6/IMPORTIN-α3 in planta. We speculate that the release of TN13 from the ER membrane in response to pathogen stimulus, and its subsequent nuclear translocation, is important for plant defense signal transduction.
Collapse
Affiliation(s)
- Charlotte Roth
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Daniel Lüdke
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Melanie Klenke
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Annalena Quathamer
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics, Institute for Microbiology and Genetics, University of Goettingen, Grisebachstrasse 8, 37077, Goettingen, Germany
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics, Institute for Microbiology and Genetics, University of Goettingen, Grisebachstrasse 8, 37077, Goettingen, Germany
| | - Marcel Wiermer
- RG Molecular Biology of Plant-Microbe Interactions, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| |
Collapse
|
21
|
Liang J, Shaulov Y, Savage-Dunn C, Boissinot S, Hoque T. Chloride intracellular channel proteins respond to heat stress in Caenorhabditis elegans. PLoS One 2017; 12:e0184308. [PMID: 28886120 PMCID: PMC5590911 DOI: 10.1371/journal.pone.0184308] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/21/2017] [Indexed: 01/05/2023] Open
Abstract
Chloride intracellular channel proteins (CLICs) are multi-functional proteins that are expressed in various cell types and differ in their subcellular location. Two CLIC homologs, EXL-1 (excretory canal abnormal like-1) and EXC-4 (excretory canal abnormal- 4), are encoded in the Caenorhabditis elegans genome, providing an excellent model to study the functional diversification of CLIC proteins. EXC-4 functions in excretory canal formation during normal animal development. However, to date, the physiological function of EXL-1 remains largely unknown. In this study, we demonstrate that EXL-1 responds specifically to heat stress and translocates from the cytoplasm to the nucleus in intestinal cells and body wall muscle cells under heat shock. In contrast, we do not observe EXC-4 nuclear translocation under heat shock. Full protein sequence analysis shows that EXL-1 bears a non-classic nuclear localization signal (NLS) that EXC-4 is lacking. All mammalian CLIC members have a nuclear localization signal, with the exception of CLIC3. Our phylogenetic analysis of the CLIC gene families across various animal species demonstrates that the duplication of CLICs in protostomes and deuterostomes occurred independently and that the NLS was subsequently lost in amniotes and nematodes, suggesting convergent evolution. We also observe that EXL-1 nuclear translocation occurs in a timely ordered manner in the intestine, from posterior to anterior regions. Finally, we find that exl-1 loss of function mutants are more susceptible to heat stress than wild-type animals, demonstrating functional relevance of the nuclear translocation. This research provides the first link between CLICs and environmental heat stress. We propose that C. elegans CLICs evolved to achieve different physiological functions through subcellular localization change and spatial separation in response to external or internal signals.
Collapse
Affiliation(s)
- Jun Liang
- Department of Science, Borough of Manhattan Community College / CUNY, New York, New York, United States of America
- * E-mail:
| | - Yakov Shaulov
- Department of Biology, Queens College, CUNY, Flushing, New York, United States of America
| | - Cathy Savage-Dunn
- Department of Biology, Queens College, CUNY, Flushing, New York, United States of America
- Biology PhD Program and Biochemistry PhD Program, the Graduate Center, New York, New York, United States of America
| | - Stephane Boissinot
- New York University Abu Dhabi, Saadiyat Island campus, Abu Dhabi, United Arab Emirates
| | - Tasmia Hoque
- Department of Science, Borough of Manhattan Community College / CUNY, New York, New York, United States of America
| |
Collapse
|
22
|
Barnabas L, Ashwin NMR, Kaverinathan K, Trentin AR, Pivato M, Sundar AR, Malathi P, Viswanathan R, Rosana OB, Neethukrishna K, Carletti P, Arrigoni G, Masi A, Agrawal GK, Rakwal R. Proteomic analysis of a compatible interaction between sugarcane and Sporisorium scitamineum. Proteomics 2016; 16:1111-22. [PMID: 26857420 DOI: 10.1002/pmic.201500245] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 01/05/2016] [Accepted: 02/02/2016] [Indexed: 02/05/2023]
Abstract
Smut caused by Sporisorium scitamineum is one of the important diseases of sugarcane with global significance. Despite the intriguing nature of sugarcane, S. scitamineum interaction, several pertinent aspects remain unexplored. This study investigates the proteome level alterations occurring in the meristem of a S. scitamineum infected susceptible sugarcane cultivar at whip emergence stage. Differentially abundant proteins were identified by 2DE coupled with MALDI-TOF/TOF-MS. Comprehensively, 53 sugarcane proteins identified were related to defence, stress, metabolism, protein folding, energy, and cell division; in addition, a putative effector of S. scitamineum, chorismate mutase, was identified. Transcript expression vis-à-vis the activity of phenylalanine ammonia lyase was relatively higher in the infected meristem. Abundance of seven candidate proteins in 2D gel profiles was in correlation with its corresponding transcript expression levels as validated by qRT-PCR. Furthermore, this study has opened up new perspectives on the interaction between sugarcane and S. scitamineum.
Collapse
Affiliation(s)
- Leonard Barnabas
- Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore, India
| | - N M R Ashwin
- Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore, India
| | - K Kaverinathan
- Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore, India
| | - Anna Rita Trentin
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | - Micaela Pivato
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | - A Ramesh Sundar
- Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore, India
| | - P Malathi
- Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore, India
| | - R Viswanathan
- Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore, India
| | - O B Rosana
- Bioinformatics Center, ICAR-Indian Institute of Spices Research, Kozhikode, India
| | - K Neethukrishna
- Bioinformatics Center, ICAR-Indian Institute of Spices Research, Kozhikode, India
| | - Paolo Carletti
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | - Giorgio Arrigoni
- Proteomics Center of Padova University, Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Antonio Masi
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | - Ganesh Kumar Agrawal
- Research Laboratory for Biotechnology and Biochemistry (RLABB), Kathmandu, Nepal.,GRADE (Global Research Arch for Developing Education) Academy Private Limited, Birgunj, Nepal
| | - Randeep Rakwal
- Research Laboratory for Biotechnology and Biochemistry (RLABB), Kathmandu, Nepal.,GRADE (Global Research Arch for Developing Education) Academy Private Limited, Birgunj, Nepal.,Tsukuba International Academy for Sport Studies (TIAS) and Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
| |
Collapse
|
23
|
Stratigi K, Chatzidoukaki O, Garinis GA. DNA damage-induced inflammation and nuclear architecture. Mech Ageing Dev 2016; 165:17-26. [PMID: 27702596 DOI: 10.1016/j.mad.2016.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/20/2016] [Accepted: 09/25/2016] [Indexed: 12/12/2022]
Abstract
Nuclear architecture and the chromatin state affect most-if not all- DNA-dependent transactions, including the ability of cells to sense DNA lesions and restore damaged DNA back to its native form. Recent evidence points to functional links between DNA damage sensors, DNA repair mechanisms and the innate immune responses. The latter raises the question of how such seemingly disparate processes operate within the intrinsically complex nuclear landscape and the chromatin environment. Here, we discuss how DNA damage-induced immune responses operate within chromatin and the distinct sub-nuclear compartments highlighting their relevance to chronic inflammation.
Collapse
Affiliation(s)
- Kalliopi Stratigi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, 70013, Heraklion, Crete, Greece
| | - Ourania Chatzidoukaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, 70013, Heraklion, Crete, Greece
| | - George A Garinis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, 70013, Heraklion, Crete, Greece; Department of Biology, University of Crete, Vassilika Vouton, GR71409, Heraklion, Crete, Greece.
| |
Collapse
|
24
|
Kim N, Kim J, Bang B, Kim I, Lee HH, Park J, Seo YS. Comparative Analyses of Tomato yellow leaf curl virus C4 Protein-Interacting Host Proteins in Healthy and Infected Tomato Tissues. THE PLANT PATHOLOGY JOURNAL 2016; 32:377-387. [PMID: 27721687 PMCID: PMC5051556 DOI: 10.5423/ppj.ft.08.2016.0165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 08/10/2016] [Accepted: 08/13/2016] [Indexed: 05/03/2023]
Abstract
Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus, is one of the most important viruses of cultivated tomatoes worldwide, mainly causing yellowing and curling of leaves with stunting in plants. TYLCV causes severe problems in sub-tropical and tropical countries, as well as in Korea. However, the mechanism of TYLCV infection remains unclear, although the function of each viral component has been identified. TYLCV C4 codes for a small protein involved in various cellular functions, including symptom determination, gene silencing, viral movement, and induction of the plant defense response. In this study, through yeast-two hybrid screenings, we identified TYLCV C4-interacting host proteins from both healthy and symptom-exhibiting tomato tissues, to determine the role of TYLCV C4 proteins in the infection processes. Comparative analyses of 28 proteins from healthy tissues and 36 from infected tissues showing interactions with TYLCV C4 indicated that TYLCV C4 mainly interacts with host proteins involved in translation, ubiquitination, and plant defense, and most interacting proteins differed between the two tissues but belong to similar molecular functional categories. Four proteins-two ribosomal proteins, S-adenosyl-L-homocysteine hydrolase, and 14-3-3 family protein-were detected in both tissues. Furthermore, the identified proteins in symptom-exhibiting tissues showed greater involvement in plant defenses. Some are key regulators, such as receptor-like kinases and pathogenesis-related proteins, of plant defenses. Thus, TYLCV C4 may contribute to the suppression of host defense during TYLCV infection and be involved in ubiquitination for viral infection.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Young-Su Seo
- Corresponding author. Phone) +82-51-510-2267, FAX) +82-51-514-1778 E-mail)
| |
Collapse
|
25
|
Gu Y, Zebell SG, Liang Z, Wang S, Kang BH, Dong X. Nuclear Pore Permeabilization Is a Convergent Signaling Event in Effector-Triggered Immunity. Cell 2016; 166:1526-1538.e11. [PMID: 27569911 DOI: 10.1016/j.cell.2016.07.042] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 06/15/2016] [Accepted: 07/26/2016] [Indexed: 01/06/2023]
Abstract
Nuclear transport of immune receptors, signal transducers, and transcription factors is an essential regulatory mechanism for immune activation. Whether and how this process is regulated at the level of the nuclear pore complex (NPC) remains unclear. Here, we report that CPR5, which plays a key inhibitory role in effector-triggered immunity (ETI) and programmed cell death (PCD) in plants, is a novel transmembrane nucleoporin. CPR5 associates with anchors of the NPC selective barrier to constrain nuclear access of signaling cargos and sequesters cyclin-dependent kinase inhibitors (CKIs) involved in ETI signal transduction. Upon activation by immunoreceptors, CPR5 undergoes an oligomer to monomer conformational switch, which coordinates CKI release for ETI signaling and reconfigures the selective barrier to allow significant influx of nuclear signaling cargos through the NPC. Consequently, these coordinated NPC actions result in simultaneous activation of diverse stress-related signaling pathways and constitute an essential regulatory mechanism specific for ETI/PCD induction.
Collapse
Affiliation(s)
- Yangnan Gu
- Department of Biology, Howard Hughes Medical Institute-Gordon and Betty Moore Foundation, P.O. Box 90338, Duke University, Durham, NC 27708, USA
| | - Sophia G Zebell
- Department of Biology, Howard Hughes Medical Institute-Gordon and Betty Moore Foundation, P.O. Box 90338, Duke University, Durham, NC 27708, USA
| | - Zizhen Liang
- School of Life Sciences, Center for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Shui Wang
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Byung-Ho Kang
- School of Life Sciences, Center for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Xinnian Dong
- Department of Biology, Howard Hughes Medical Institute-Gordon and Betty Moore Foundation, P.O. Box 90338, Duke University, Durham, NC 27708, USA.
| |
Collapse
|
26
|
Herud O, Weijers D, Lau S, Jürgens G. Auxin responsiveness of the MONOPTEROS-BODENLOS module in primary root initiation critically depends on the nuclear import kinetics of the Aux/IAA inhibitor BODENLOS. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:269-77. [PMID: 26714008 DOI: 10.1111/tpj.13108] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/07/2015] [Accepted: 12/14/2015] [Indexed: 05/28/2023]
Abstract
Primary root formation in early embryogenesis of Arabidopsis thaliana is initiated with the specification of a single cell called hypophysis. This initial step requires the auxin-dependent release of the transcription factor MONOPTEROS (MP, also known as ARF5) from its inhibition by the Aux/IAA protein BODENLOS (BDL, also known as IAA12). Auxin-insensitive bdl mutant embryos and mp loss-of-function embryos fail to specify the hypophysis, giving rise to rootless seedlings. A suppressor screen of rootless bdl mutant seedlings yielded a mutation in the nuclear import receptor IMPORTIN-ALPHA 6 (IMPα6) that promoted primary root formation through rescue of the embryonic hypophysis defects, without causing additional phenotypic changes. Aux/IAA proteins are continually synthesized and degraded, which is essential for rapid transcriptional responses to changing auxin concentrations. Nuclear translocation of bdl:3×GFP was slowed down in impα6 mutants as measured by fluorescence recovery after photobleaching (FRAP) analysis, which correlated with the reduced inhibition of MP by bdl in transient expression assays in impα6 knock-down protoplasts. The MP-BDL module acts like an auxin-triggered genetic switch because MP activates its own expression as well as the expression of its inhibitor BDL. Using an established simulation model, we determined that the reduced nuclear translocation rate of BDL in impα6 mutant embryos rendered the auxin-triggered switch unstable, impairing the fast response to changes in auxin concentration. Our results suggest that the instability of the inhibitor BDL necessitates a fast nuclear uptake in order to reach the critical threshold level required for auxin responsiveness of the MP-BDL module in primary root initiation.
Collapse
Affiliation(s)
- Ole Herud
- Department of Cell Biology, Max Planck Institute for Developmental Biology, Tübingen, 72076, Germany
| | - Dolf Weijers
- Department of Developmental Genetics, Center for Plant Molecular Biology, University of Tübingen, Tübingen, 72076, Germany
| | - Steffen Lau
- Department of Cell Biology, Max Planck Institute for Developmental Biology, Tübingen, 72076, Germany
| | - Gerd Jürgens
- Department of Cell Biology, Max Planck Institute for Developmental Biology, Tübingen, 72076, Germany
- Department of Developmental Genetics, Center for Plant Molecular Biology, University of Tübingen, Tübingen, 72076, Germany
| |
Collapse
|
27
|
Panstruga R, Kuhn H. Introduction to a Virtual Special Issue on cell biology at the plant-microbe interface. THE NEW PHYTOLOGIST 2015; 207:931-8. [PMID: 26235485 DOI: 10.1111/nph.13551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Affiliation(s)
- Ralph Panstruga
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, 52056, Aachen, Germany
| | - Hannah Kuhn
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, 52056, Aachen, Germany
| |
Collapse
|
28
|
Nuclear Localization of the DNA Repair Scaffold XRCC1: Uncovering the Functional Role of a Bipartite NLS. Sci Rep 2015; 5:13405. [PMID: 26304019 PMCID: PMC4548243 DOI: 10.1038/srep13405] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/17/2015] [Indexed: 12/23/2022] Open
Abstract
We have characterized the nuclear localization signal (NLS) of XRCC1 structurally using X-ray crystallography and functionally using fluorescence imaging. Crystallography and binding studies confirm the bipartite nature of the XRCC1 NLS interaction with Importin α (Impα) in which the major and minor binding motifs are separated by >20 residues, and resolve previous inconsistent determinations. Binding studies of peptides corresponding to the bipartite NLS, as well as its major and minor binding motifs, to both wild-type and mutated forms of Impα reveal pronounced cooperative binding behavior that is generated by the proximity effect of the tethered major and minor motifs of the NLS. The cooperativity stems from the increased local concentration of the second motif near its cognate binding site that is a consequence of the stepwise binding behavior of the bipartite NLS. We predict that the stepwise dissociation of the NLS from Impα facilitates unloading by providing a partially complexed intermediate that is available for competitive binding by Nup50 or the Importin β binding domain. This behavior provides a basis for meeting the intrinsically conflicting high affinity and high flux requirements of an efficient nuclear transport system.
Collapse
|
29
|
Bernardes NE, Takeda AAS, Dreyer TR, Freitas FZ, Bertolini MC, Fontes MRM. Structure of Importin-α from a Filamentous Fungus in Complex with a Classical Nuclear Localization Signal. PLoS One 2015; 10:e0128687. [PMID: 26091498 PMCID: PMC4474859 DOI: 10.1371/journal.pone.0128687] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 04/29/2015] [Indexed: 01/07/2023] Open
Abstract
Neurospora crassa is a filamentous fungus that has been extensively studied as a model organism for eukaryotic biology, providing fundamental insights into cellular processes such as cell signaling, growth and differentiation. To advance in the study of this multicellular organism, an understanding of the specific mechanisms for protein transport into the cell nucleus is essential. Importin-α (Imp-α) is the receptor for cargo proteins that contain specific nuclear localization signals (NLSs) that play a key role in the classical nuclear import pathway. Structures of Imp-α from different organisms (yeast, rice, mouse, and human) have been determined, revealing that this receptor possesses a conserved structural scaffold. However, recent studies have demonstrated that the Impα mechanism of action may vary significantly for different organisms or for different isoforms from the same organism. Therefore, structural, functional, and biophysical characterization of different Impα proteins is necessary to understand the selectivity of nuclear transport. Here, we determined the first crystal structure of an Impα from a filamentous fungus which is also the highest resolution Impα structure already solved to date (1.75 Å). In addition, we performed calorimetric analysis to determine the affinity and thermodynamic parameters of the interaction between Imp-α and the classical SV40 NLS peptide. The comparison of these data with previous studies on Impα proteins led us to demonstrate that N. crassa Imp-α possess specific features that are distinct from mammalian Imp-α but exhibit important similarities to rice Imp-α, particularly at the minor NLS binding site.
Collapse
Affiliation(s)
- Natalia E. Bernardes
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil
| | - Agnes A. S. Takeda
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil
| | - Thiago R. Dreyer
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil
| | - Fernanda Z. Freitas
- Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, UNESP, Araraquara, SP, Brazil
| | - Maria Célia Bertolini
- Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, UNESP, Araraquara, SP, Brazil
| | - Marcos R. M. Fontes
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu, SP, Brazil
- * E-mail:
| |
Collapse
|
30
|
Wirthmueller L, Roth C, Fabro G, Caillaud MC, Rallapalli G, Asai S, Sklenar J, Jones AME, Wiermer M, Jones JDG, Banfield MJ. Probing formation of cargo/importin-α transport complexes in plant cells using a pathogen effector. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:40-52. [PMID: 25284001 PMCID: PMC4350430 DOI: 10.1111/tpj.12691] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 09/26/2014] [Accepted: 09/29/2014] [Indexed: 05/17/2023]
Abstract
Importin-αs are essential adapter proteins that recruit cytoplasmic proteins destined for active nuclear import to the nuclear transport machinery. Cargo proteins interact with the importin-α armadillo repeat domain via nuclear localization sequences (NLSs), short amino acids motifs enriched in Lys and Arg residues. Plant genomes typically encode several importin-α paralogs that can have both specific and partially redundant functions. Although some cargos are preferentially imported by a distinct importin-α it remains unknown how this specificity is generated and to what extent cargos compete for binding to nuclear transport receptors. Here we report that the effector protein HaRxL106 from the oomycete pathogen Hyaloperonospora arabidopsidis co-opts the host cell's nuclear import machinery. We use HaRxL106 as a probe to determine redundant and specific functions of importin-α paralogs from Arabidopsis thaliana. A crystal structure of the importin-α3/MOS6 armadillo repeat domain suggests that five of the six Arabidopsis importin-αs expressed in rosette leaves have an almost identical NLS-binding site. Comparison of the importin-α binding affinities of HaRxL106 and other cargos in vitro and in plant cells suggests that relatively small affinity differences in vitro affect the rate of transport complex formation in vivo. Our results suggest that cargo affinity for importin-α, sequence variation at the importin-α NLS-binding sites and tissue-specific expression levels of importin-αs determine formation of cargo/importin-α transport complexes in plant cells.
Collapse
Affiliation(s)
- Lennart Wirthmueller
- The Sainsbury LaboratoryNorwich Research Park, Norwich, NR4 7UH, UK
- Department of Biological Chemistry, John Innes CentreNorwich Research Park, Norwich, NR4 7UH, UK
| | - Charlotte Roth
- Department of Plant Cell Biology, Georg-August-UniversityJulia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | - Georgina Fabro
- The Sainsbury LaboratoryNorwich Research Park, Norwich, NR4 7UH, UK
| | | | | | - Shuta Asai
- The Sainsbury LaboratoryNorwich Research Park, Norwich, NR4 7UH, UK
| | - Jan Sklenar
- The Sainsbury LaboratoryNorwich Research Park, Norwich, NR4 7UH, UK
| | | | - Marcel Wiermer
- Department of Plant Cell Biology, Georg-August-UniversityJulia-Lermontowa-Weg 3, 37077, Goettingen, Germany
| | | | - Mark J Banfield
- Department of Biological Chemistry, John Innes CentreNorwich Research Park, Norwich, NR4 7UH, UK
| |
Collapse
|
31
|
Chang CW, Williams SJ, Couñago RM, Kobe B. Structural basis of interaction of bipartite nuclear localization signal from Agrobacterium VirD2 with rice importin-α. MOLECULAR PLANT 2014; 7:1061-1064. [PMID: 24503158 DOI: 10.1093/mp/ssu014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Chiung-Wen Chang
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience, and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Qld 4072, Australia
| | - Simon J Williams
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience, and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Qld 4072, Australia
| | - Rafael Miguez Couñago
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience, and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Qld 4072, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience, and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Qld 4072, Australia.
| |
Collapse
|
32
|
Rivas S, Deslandes L. Nuclear components and dynamics during plant innate immunity. FRONTIERS IN PLANT SCIENCE 2013; 4:481. [PMID: 24319451 PMCID: PMC3837220 DOI: 10.3389/fpls.2013.00481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 11/06/2013] [Indexed: 06/03/2023]
Affiliation(s)
- Susana Rivas
- Laboratoire des Interactions Plantes-Microorganismes, Institut National de la Recherche Agronomique, UMR441Castanet-Tolosan, France
- Laboratoire des Interactions Plantes-Microorganismes, Centre National de la Recherche Scientifique, UMR2594Castanet-Tolosan, France
| | - Laurent Deslandes
- Laboratoire des Interactions Plantes-Microorganismes, Institut National de la Recherche Agronomique, UMR441Castanet-Tolosan, France
- Laboratoire des Interactions Plantes-Microorganismes, Centre National de la Recherche Scientifique, UMR2594Castanet-Tolosan, France
| |
Collapse
|
33
|
Chang C, Zhang L, Shen QH. Partitioning, repressing and derepressing: dynamic regulations in MLA immune receptor triggered defense signaling. FRONTIERS IN PLANT SCIENCE 2013; 4:396. [PMID: 24115952 PMCID: PMC3792363 DOI: 10.3389/fpls.2013.00396] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 09/16/2013] [Indexed: 05/09/2023]
Abstract
Plants and animals have evolved intracellular nucleotide-binding domain and leucine-rich repeat-containing immune receptors (NLRs) to perceive non-self and trigger immune responses. Plant NLRs detect strain-specific pathogen effectors and activate immune signaling leading to extensive transcriptional reprogramming and termination of pathogen infection. Here we review the recent findings in barley MLA immune receptor mediated immune responses against the barley powdery mildew fungus. We focus on nucleocytoplasmic partitioning of immune receptor, bifurcation of immune signaling, transcriptional repression and derepression connecting receptor activation to immune responses. We also discuss similar findings from other plant NLRs where appropriate.
Collapse
Affiliation(s)
- Cheng Chang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
- Graduate University of Chinese Academy of SciencesBeijing, China
| | - Ling Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
| | - Qian-Hua Shen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China
- *Correspondence: Qian-Hua Shen, State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China e-mail:
| |
Collapse
|
34
|
Chang CW, Couñago RM, Williams SJ, Boden M, Kobe B. The distribution of different classes of nuclear localization signals (NLSs) in diverse organisms and the utilization of the minor NLS-binding site inplantnuclear import factor importin-α. PLANT SIGNALING & BEHAVIOR 2013; 8:25976. [PMID: 24270630 PMCID: PMC4091121 DOI: 10.4161/psb.25976] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 07/31/2013] [Indexed: 05/29/2023]
Abstract
The specific recognition between the import receptor importin-α and the nuclear localization signals (NLSs) is crucial to ensure the selective transport of cargoes into the nucleus. NLSs contain 1 or 2 clusters of positively charged amino acids, which usually bind to the major (monopartite NLSs) or both minor and major NLS-binding sites (bipartite NLSs). In our recent study, we determined the structure of importin-α1a from rice (Oryza sativa), and made 2 observations that suggest an increased utilization of the minor NLS-binding site in this protein. First, unlike the mammalian protein, both the major and minor NLS-binding sites are auto-inhibited in the unliganded rice protein. Second, we showed that NLSs of the "plant-specific" class preferentially bind to the minor NLS-binding site of rice importin-α. Here, we show that a distinct group of "minor site-specific" NLSs also bind to the minor site of the rice protein. We further show a greater enrichment of proteins containing these "plant-specific" and "minor site-specific" NLSs in the rice proteome. However, the analysis of the distribution of different classes of NLSs in diverse eukaryotes shows that in all organisms, the minor site-specific NLSs are much less prevalent than the classical monopartite and bipartite NLSs.
Collapse
Affiliation(s)
- Chiung-Wen Chang
- School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience; University of Queensland; Brisbane, QLD Australia
- Australian Infectious Diseases Research Centre; University of Queensland; Brisbane, QLD Australia
| | - Rafael Miguez Couñago
- School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience; University of Queensland; Brisbane, QLD Australia
- Australian Infectious Diseases Research Centre; University of Queensland; Brisbane, QLD Australia
| | - Simon J Williams
- School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience; University of Queensland; Brisbane, QLD Australia
- Australian Infectious Diseases Research Centre; University of Queensland; Brisbane, QLD Australia
| | - Mikael Boden
- School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience; University of Queensland; Brisbane, QLD Australia
- School of Information Technology and Electrical Engineering; University of Queensland; Brisbane, QLD Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience; University of Queensland; Brisbane, QLD Australia
- Australian Infectious Diseases Research Centre; University of Queensland; Brisbane, QLD Australia
| |
Collapse
|