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Turek I, Wong A, Domingo G, Vannini C, Bracale M, Irving H, Gehring C. Moonlighting Crypto-Enzymes and Domains as Ancient and Versatile Signaling Devices. Int J Mol Sci 2024; 25:9535. [PMID: 39273482 PMCID: PMC11394779 DOI: 10.3390/ijms25179535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 08/27/2024] [Accepted: 08/27/2024] [Indexed: 09/15/2024] Open
Abstract
Increasing numbers of reports have revealed novel catalytically active cryptic guanylate cyclases (GCs) and adenylate cyclases (ACs) operating within complex proteins in prokaryotes and eukaryotes. Here we review the structural and functional aspects of some of these cyclases and provide examples that illustrate their roles in the regulation of the intramolecular functions of complex proteins, such as the phytosulfokine receptor (PSKR), and reassess their contribution to signal generation and tuning. Another multidomain protein, Arabidopsis thaliana K+ uptake permease (AtKUP5), also harbors multiple catalytically active sites including an N-terminal AC and C-terminal phosphodiesterase (PDE) with an abscisic acid-binding site. We argue that this architecture may enable the fine-tuning and/or sensing of K+ flux and integrate hormone responses to cAMP homeostasis. We also discuss how searches with motifs based on conserved amino acids in catalytic centers led to the discovery of GCs and ACs and propose how this approach can be applied to discover hitherto masked active sites in bacterial, fungal, and animal proteomes. Finally, we show that motif searches are a promising approach to discover ancient biological functions such as hormone or gas binding.
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Affiliation(s)
- Ilona Turek
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organisation, East Geelong, VIC 3220, Australia
| | - Aloysius Wong
- Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou 325060, China
- Wenzhou Municipal Key Lab for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou 325060, China
- Zhejiang Bioinformatics International Science and Technology Cooperation Center, Wenzhou-Kean University, Wenzhou 325060, China
| | - Guido Domingo
- Biotechnology and Life Science Department, University of Insubria, 21100 Varese, Italy
| | - Candida Vannini
- Biotechnology and Life Science Department, University of Insubria, 21100 Varese, Italy
| | - Marcella Bracale
- Biotechnology and Life Science Department, University of Insubria, 21100 Varese, Italy
| | - Helen Irving
- La Trobe Institute of Molecular Sciences, La Trobe University, Bendigo, VIC 3552, Australia
- Holsworth Initiative for Medical Research, Rural People, Department of Rural Clinical Sciences, La Trobe Rural Health School, La Trobe University, Bendigo, VIC 3552, Australia
| | - Chris Gehring
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06121 Perugia, Italy
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2
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Fang H, Zuo J, Ma Q, Zhang X, Xu Y, Ding S, Wang J, Luo Q, Li Y, Wu C, Lv J, Yu J, Shi K. Phytosulfokine promotes fruit ripening and quality via phosphorylation of transcription factor DREB2F in tomato. PLANT PHYSIOLOGY 2024; 194:2739-2754. [PMID: 38214105 DOI: 10.1093/plphys/kiae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/28/2023] [Accepted: 12/16/2023] [Indexed: 01/13/2024]
Abstract
Phytosulfokine (PSK), a plant peptide hormone with a wide range of biological functions, is recognized by its receptor PHYTOSULFOKINE RECEPTOR 1 (PSKR1). Previous studies have reported that PSK plays important roles in plant growth, development, and stress responses. However, the involvement of PSK in fruit development and quality formation remains largely unknown. Here, using tomato (Solanum lycopersicum) as a research model, we show that exogenous application of PSK promotes the initiation of fruit ripening and quality formation, while these processes are delayed in pskr1 mutant fruits. Transcriptomic profiling revealed that molecular events and metabolic pathways associated with fruit ripening and quality formation are affected in pskr1 mutant lines and transcription factors are involved in PSKR1-mediated ripening. Yeast screening further identified that DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2F (DREB2F) interacts with PSKR1. Silencing of DREB2F delayed the initiation of fruit ripening and inhibited the promoting effect of PSK on fruit ripening. Moreover, the interaction between PSKR1 and DREB2F led to phosphorylation of DREB2F. PSK improved the efficiency of DREB2F phosphorylation by PSKR1 at the tyrosine-30 site, and the phosphorylation of this site increased the transcription level of potential target genes related to the ripening process and functioned in promoting fruit ripening and quality formation. These findings shed light on the involvement of PSK and its downstream signaling molecule DREB2F in controlling climacteric fruit ripening, offering insights into the regulatory mechanisms governing ripening processes in fleshy fruits.
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Affiliation(s)
- Hanmo Fang
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Jinhua Zuo
- Institute of Agro-Products Processing and Food Nutrition, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Qiaomei Ma
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Xuanbo Zhang
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yuanrui Xu
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Shuting Ding
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Jiao Wang
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Qian Luo
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yimei Li
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Changqi Wu
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Jianrong Lv
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Jingquan Yu
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Kai Shi
- Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
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Hu Z, Fang H, Zhu C, Gu S, Ding S, Yu J, Shi K. Ubiquitylation of PHYTOSULFOKINE RECEPTOR 1 modulates the defense response in tomato. PLANT PHYSIOLOGY 2023; 192:2507-2522. [PMID: 36946197 PMCID: PMC10315268 DOI: 10.1093/plphys/kiad188] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/22/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
Phytosulfokine (PSK) is a danger-associated molecular pattern recognized by PHYTOSULFOKINE RECEPTOR 1 (PSKR1) and initiates intercellular signaling to coordinate different physiological processes, especially in the defense response to the necrotrophic fungus Botrytis cinerea. The activity of peptide receptors is largely influenced by different posttranslational modifications, which determine intercellular peptide signal outputs. To date, the posttranslational modification to PHYTOSULFOKINE RECEPTOR 1 (PSKR1) remains largely unknown. Here, we show that tomato (Solanum lycopersicum) PSKR1 is regulated by the ubiquitin/proteasome degradation pathway. Using multiple protein-protein interactions and ubiquitylation analyses, we identified that plant U-box E3 ligases PUB12 and PUB13 interacted with PSKR1, among which PUB13 caused PSKR1 ubiquitylation at Lys-748 and Lys-905 sites to control PSKR1 abundance. However, this posttranslational modification was attenuated upon addition of PSK. Moreover, the disease symptoms observed in PUB13 knock-down and overexpression lines demonstrated that PUB13 significantly suppressed the PSK-initiated defense response. This highlights an important regulatory function for the turnover of a peptide receptor by E3 ligase-mediated ubiquitylation in the plant defense response.
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Affiliation(s)
- Zhangjian Hu
- Department of Horticulture, Zhejiang University, Hangzhou 310058, China
- Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, China
| | - Hanmo Fang
- Department of Horticulture, Zhejiang University, Hangzhou 310058, China
| | - Changan Zhu
- Department of Horticulture, Zhejiang University, Hangzhou 310058, China
| | - Shaohan Gu
- Department of Horticulture, Zhejiang University, Hangzhou 310058, China
| | - Shuting Ding
- Department of Horticulture, Zhejiang University, Hangzhou 310058, China
| | - Jingquan Yu
- Department of Horticulture, Zhejiang University, Hangzhou 310058, China
- Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, China
| | - Kai Shi
- Department of Horticulture, Zhejiang University, Hangzhou 310058, China
- Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, China
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4
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Activation loop phosphorylaton of a non-RD receptor kinase initiates plant innate immune signaling. Proc Natl Acad Sci U S A 2021; 118:2108242118. [PMID: 34531323 PMCID: PMC8463890 DOI: 10.1073/pnas.2108242118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2021] [Indexed: 01/01/2023] Open
Abstract
Receptor kinases (RKs) are fundamental for extracellular sensing and regulate development and stress responses across kingdoms. In plants, leucine-rich repeat receptor kinases (LRR-RKs) are primarily peptide receptors that regulate responses to myriad internal and external stimuli. Phosphorylation of LRR-RK cytoplasmic domains is among the earliest responses following ligand perception, and reciprocal transphosphorylation between a receptor and its coreceptor is thought to activate the receptor complex. Originally proposed based on characterization of the brassinosteroid receptor, the prevalence of complex activation via reciprocal transphosphorylation across the plant RK family has not been tested. Using the LRR-RK ELONGATION FACTOR TU RECEPTOR (EFR) as a model, we set out to understand the steps critical for activating RK complexes. While the EFR cytoplasmic domain is an active protein kinase in vitro and is phosphorylated in a ligand-dependent manner in vivo, catalytically deficient EFR variants are functional in antibacterial immunity. These results reveal a noncatalytic role for EFR in triggering immune signaling and indicate that reciprocal transphoshorylation is not a ubiquitous requirement for LRR-RK complex activation. Rather, our analysis of EFR along with a detailed survey of the literature suggests a distinction between LRR-RKs with RD- versus non-RD protein kinase domains. Based on newly identified phosphorylation sites that regulate the activation state of the EFR complex in vivo, we propose that LRR-RK complexes containing a non-RD protein kinase may be regulated by phosphorylation-dependent conformational changes of the ligand-binding receptor, which could initiate signaling either allosterically or through driving the dissociation of negative regulators of the complex.
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Kaufmann C, Stührwohldt N, Sauter M. Tyrosylprotein sulfotransferase-dependent and -independent regulation of root development and signaling by PSK LRR receptor kinases in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5508-5521. [PMID: 34028532 PMCID: PMC8318253 DOI: 10.1093/jxb/erab233] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/20/2021] [Indexed: 05/13/2023]
Abstract
Tyrosine-sulfated peptides are key regulators of plant growth and development. The disulfated pentapeptide phytosulfokine (PSK) mediates growth via leucine-rich repeat receptor-like kinases, PSKR1 and PSKR2. PSK receptors (PSKRs) are part of a response module at the plasma membrane that mediates short-term growth responses, but downstream signaling of transcriptional regulation remains unexplored. In Arabidopsis, tyrosine sulfation is catalyzed by a single-copy gene (TPST; encoding tyrosylprotein sulfotransferase). We performed a microarray-based transcriptome analysis in the tpst-1 mutant background that lacks sulfated peptides to identify PSK-regulated genes and genes that are regulated by other sulfated peptides. Of the 169 PSK-regulated genes, several had functions in root growth and development, in agreement with shorter roots and a higher lateral root density in tpst-1. Further, tpst-1 roots developed higher numbers of root hairs, and PSK induced expression of WEREWOLF (WER), its paralog MYB DOMAIN PROTEIN 23 (MYB23), and At1g66800 that maintain non-hair cell fate. The tpst-1 pskr1-3 pskr2-1 mutant showed even shorter roots, and higher lateral root and root hair density than tpst-1, revealing unexpected synergistic effects of ligand and PSKR deficiencies. While residual activities may exist, overexpression of PSKR1 in the tpst-1 background induced root growth, suggesting that PSKR1 may be active in the absence of sulfated ligands.
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Affiliation(s)
- Christine Kaufmann
- Plant Developmental Biology and Physiology, University of Kiel, Kiel, Germany
| | - Nils Stührwohldt
- Plant Developmental Biology and Physiology, University of Kiel, Kiel, Germany
| | - Margret Sauter
- Plant Developmental Biology and Physiology, University of Kiel, Kiel, Germany
- Correspondence:
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Turek I, Irving H. Moonlighting Proteins Shine New Light on Molecular Signaling Niches. Int J Mol Sci 2021; 22:1367. [PMID: 33573037 PMCID: PMC7866414 DOI: 10.3390/ijms22031367] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 02/06/2023] Open
Abstract
Plants as sessile organisms face daily environmental challenges and have developed highly nuanced signaling systems to enable suitable growth, development, defense, or stalling responses. Moonlighting proteins have multiple tasks and contribute to cellular signaling cascades where they produce additional variables adding to the complexity or fuzziness of biological systems. Here we examine roles of moonlighting kinases that also generate 3',5'-cyclic guanosine monophosphate (cGMP) in plants. These proteins include receptor like kinases and lipid kinases. Their guanylate cyclase activity potentiates the development of localized cGMP-enriched nanodomains or niches surrounding the kinase and its interactome. These nanodomains contribute to allosteric regulation of kinase and other molecules in the immediate complex directly or indirectly modulating signal cascades. Effects include downregulation of kinase activity, modulation of other members of the protein complexes such as cyclic nucleotide gated channels and potential triggering of cGMP-dependent degradation cascades terminating signaling. The additional layers of information provided by the moonlighting kinases are discussed in terms of how they may be used to provide a layer of fuzziness to effectively modulate cellular signaling cascades.
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Affiliation(s)
| | - Helen Irving
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC 3550, Australia;
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Nagar P, Kumar A, Jain M, Kumari S, Mustafiz A. Genome-wide analysis and transcript profiling of PSKR gene family members in Oryza sativa. PLoS One 2020; 15:e0236349. [PMID: 32701993 PMCID: PMC7377467 DOI: 10.1371/journal.pone.0236349] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/04/2020] [Indexed: 11/18/2022] Open
Abstract
Peptide signalling is an integral part of cell-to-cell communication which helps to relay the information responsible for coordinating cell proliferation and differentiation. Phytosulfokine Receptor (PSKR) is a transmembrane LRR-RLK family protein with a binding site for small signalling peptide, phytosulfokine (PSK). PSK signalling through PSKR promotes normal growth and development and also plays a role in defense responses. Like other RLKs, these PSKRs might have a role in signal transduction pathways related to abiotic stress responses. Genome-wide analysis of phytosulfokine receptor gene family has led to the identification of fifteen putative members in the Oryza sativa genome. The expression analysis of OsPSKR genes done using RNA-seq data, showed that these genes were differentially expressed in different tissues and responded specifically to heat, salt, drought and cold stress. Furthermore, the real-time quantitative PCR for fifteen OsPSKR genes revealed temporally and spatially regulated gene expression corresponding to salinity and drought stress. Our results provide useful information for a better understanding of OsPSKR genes and provide the foundation for additional functional exploration of the rice PSKR gene family in development and stress response.
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Affiliation(s)
- Preeti Nagar
- Plant Molecular Biology Laboratory, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
| | - Ashish Kumar
- Plant Molecular Biology Laboratory, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
| | - Muskan Jain
- Plant Molecular Biology Laboratory, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
| | - Sumita Kumari
- School of Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology, Jammu, JK, India
| | - Ananda Mustafiz
- Plant Molecular Biology Laboratory, Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
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Kaufmann C, Sauter M. Sulfated plant peptide hormones. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4267-4277. [PMID: 31231771 PMCID: PMC6698702 DOI: 10.1093/jxb/erz292] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/11/2019] [Indexed: 05/08/2023]
Abstract
Sulfated peptides are plant hormones that are active at nanomolar concentrations. The sulfation at one or more tyrosine residues is catalysed by tyrosylprotein sulfotransferase (TPST), which is encoded by a single-copy gene. The sulfate group is provided by the co-substrate 3´-phosphoadenosine 5´-phosphosulfate (PAPS), which links synthesis of sulfated signaling peptides to sulfur metabolism. The precursor proteins share a conserved DY-motif that is implicated in specifying tyrosine sulfation. Several sulfated peptides undergo additional modification such as hydroxylation of proline and glycosylation of hydroxyproline. The modifications render the secreted signaling molecules active and stable. Several sulfated signaling peptides have been shown to be perceived by leucine-rich repeat receptor-like kinases (LRR-RLKs) but have signaling pathways that, for the most part, are yet to be elucidated. Sulfated peptide hormones regulate growth and a wide variety of developmental processes, and intricately modulate immunity to pathogens. While basic research on sulfated peptides has made steady progress, their potential in agricultural and pharmaceutical applications has yet to be explored.
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Affiliation(s)
- Christine Kaufmann
- Plant Developmental Biology and Physiology, University of Kiel, Am Botanischen Garten, Kiel, Germany
- Correspondence:
| | - Margret Sauter
- Plant Developmental Biology and Physiology, University of Kiel, Am Botanischen Garten, Kiel, Germany
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9
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Irving HR, Cahill DM, Gehring C. Moonlighting Proteins and Their Role in the Control of Signaling Microenvironments, as Exemplified by cGMP and Phytosulfokine Receptor 1 (PSKR1). FRONTIERS IN PLANT SCIENCE 2018; 9:415. [PMID: 29643865 PMCID: PMC5883070 DOI: 10.3389/fpls.2018.00415] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 03/14/2018] [Indexed: 05/24/2023]
Abstract
Signal generating and processing complexes and changes in concentrations of messenger molecules such as calcium ions and cyclic nucleotides develop gradients that have critical roles in relaying messages within cells. Cytoplasmic contents are densely packed, and in plant cells this is compounded by the restricted cytoplasmic space. To function in such crowded spaces, scaffold proteins have evolved to keep key enzymes in the correct place to ensure ordered spatial and temporal and stimulus-specific message generation. Hence, throughout the cytoplasm there are gradients of messenger molecules that influence signaling processes. However, it is only recently becoming apparent that specific complexes involving receptor molecules can generate multiple signal gradients and enriched microenvironments around the cytoplasmic domains of the receptor that regulate downstream signaling. Such gradients or signal circuits can involve moonlighting proteins, so called because they can enable fine-tune signal cascades via cryptic additional functions that are just being defined. This perspective focuses on how enigmatic activity of moonlighting proteins potentially contributes to regional intracellular microenvironments. For instance, the proteins associated with moonlighting proteins that generate cyclic nucleotides may be regulated by cyclic nucleotide binding directly or indirectly. In this perspective, we discuss how generation of cyclic nucleotide-enriched microenvironments can promote and regulate signaling events. As an example, we use the phytosulfokine receptor (PSKR1), discuss the function of its domains and their mutual interactions and argue that this complex architecture and function enhances tuning of signals in microenvironments.
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Affiliation(s)
- Helen R. Irving
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
- La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - David M. Cahill
- Faculty of Science Engineering and Built Environment, Deakin University, Geelong, VIC, Australia
| | - Chris Gehring
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
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Kwezi L, Wheeler JI, Marondedze C, Gehring C, Irving HR. Intramolecular crosstalk between catalytic activities of receptor kinases. PLANT SIGNALING & BEHAVIOR 2018; 13:e1430544. [PMID: 29355445 PMCID: PMC5846547 DOI: 10.1080/15592324.2018.1430544] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/12/2018] [Indexed: 05/21/2023]
Abstract
Signal modulation is important for the growth and development of plants and this process is mediated by a number of factors including physiological growth regulators and their associated signal transduction pathways. Protein kinases play a central role in signaling, including those involving pathogen response mechanisms. We previously demonstrated an active guanylate cyclase (GC) catalytic center in the brassinosteroid insensitive receptor (AtBRI1) within an active intracellular kinase domain resulting in dual enzymatic activity. Here we propose a novel type of receptor architecture that is characterized by a functional GC catalytic center nested in the cytosolic kinase domain enabling intramolecular crosstalk. This may be through a cGMP-AtBRI1 complex forming that may induce a negative feedback mechanism leading to desensitisation of the receptor, regulated through the cGMP production pathway. We further argue that the comparatively low but highly localized cGMP generated by the GC in response to a ligand is sufficient to modulate the kinase activity. This type of receptor therefore provides a molecular switch that directly and/or indirectly affects ligand dependent phosphorylation of downstream signaling cascades and suggests that subsequent signal transduction and modulation works in conjunction with the kinase in downstream signaling.
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Affiliation(s)
- Lusisizwe Kwezi
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
- Biosciences, Council For Scientific and Industrial Research, Brummeria, Pretoria, South Africa
| | - Janet I. Wheeler
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
- AgriBio, La Trobe University, Bundoora, VIC, Australia
| | - Claudius Marondedze
- Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CEA/DRF/BIG, INRA UMR1417, CNRS UMR5168, Grenoble Cedex 9, France
| | - Chris Gehring
- Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- Department of Chemistry, Biology & Biotechnology, University of Perugia, Perugia, Umbria, Italy
| | - Helen R. Irving
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
- Pharmacy & Applied Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo VIC, Australia
- CONTACT Helen R. Irving La Trobe Institute for Molecular Science, La Trobe University, PO Box 199, Bendigo VIC 3552,Australia
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11
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Wheeler JI, Wong A, Marondedze C, Groen AJ, Kwezi L, Freihat L, Vyas J, Raji MA, Irving HR, Gehring C. The brassinosteroid receptor BRI1 can generate cGMP enabling cGMP-dependent downstream signaling. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 91:590-600. [PMID: 28482142 DOI: 10.1111/tpj.13589] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 05/24/2023]
Abstract
The brassinosteroid receptor brassinosteroid insensitive 1 (BRI1) is a member of the leucine-rich repeat receptor-like kinase family. The intracellular kinase domain of BRI1 is an active kinase and also encapsulates a guanylate cyclase catalytic centre. Using liquid chromatography tandem mass spectrometry, we confirmed that the recombinant cytoplasmic domain of BRI1 generates pmol amounts of cGMP per μg protein with a preference for magnesium over manganese as a co-factor. Importantly, a functional BRI1 kinase is essential for optimal cGMP generation. Therefore, the guanylate cyclase activity of BRI1 is modulated by the kinase while cGMP, the product of the guanylate cyclase, in turn inhibits BRI1 kinase activity. Furthermore, we show using Arabidopsis root cell cultures that cGMP rapidly potentiates phosphorylation of the downstream substrate brassinosteroid signaling kinase 1 (BSK1). Taken together, our results suggest that cGMP acts as a modulator that enhances downstream signaling while dampening signal generation from the receptor.
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Affiliation(s)
- Janet I Wheeler
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, 3052, Australia
- AgriBio, La Trobe University, Bundoora, VIC, 3083, Australia
| | - Aloysius Wong
- Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- College of Natural, Applied and Health Sciences, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang Province, China, 325060
| | - Claudius Marondedze
- Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Arnoud J Groen
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Lusisizwe Kwezi
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, 3052, Australia
- Council for Scientific and Industrial Research, Biosciences, Brummeria, Pretoria, 0001, South Africa
| | - Lubna Freihat
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, 3052, Australia
| | - Jignesh Vyas
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, 3052, Australia
| | - Misjudeen A Raji
- Analytical Chemistry Core Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Helen R Irving
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, 3052, Australia
| | - Chris Gehring
- Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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12
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Popescu SC, Brauer EK, Dimlioglu G, Popescu GV. Insights into the Structure, Function, and Ion-Mediated Signaling Pathways Transduced by Plant Integrin-Linked Kinases. FRONTIERS IN PLANT SCIENCE 2017; 8:376. [PMID: 28421082 PMCID: PMC5376563 DOI: 10.3389/fpls.2017.00376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/06/2017] [Indexed: 05/04/2023]
Abstract
Kinases facilitate detection of extracellular signals and set in motion cellular responses for plant adaptation and survival. Some of the energy utilized for kinase signal processing is produced through the activity of ion transporters. Additionally, the synergy between cellular ions and signal transduction influences plant response to pathogens, and their growth and development. In plants, the signaling elements that connect cell wall and membrane sensors with ion homeostasis and transport-mediated processes are largely unknown. Current research indicates that plant Integrin-Linked Kinases (ILKs), a subfamily Raf-like MAP2K Kinases, may have evolved to fulfill this role. In this review, we explore new findings on plant ILKs placing a particular focus on the connection between ILKs proteins unique structural features and ILKs functions. The ankyrin repeat motifs and the kinase domains of ILKs in Arabidopsis and land plants lineage, respectively, are analyzed and discussed as potential determinants of ILKs' metal ion cofactor specificity and their enzymatic and interaction activities. Further, ILKs regulation through gene expression, subcellular localization, and ions and ion transporters is reviewed in the context of recent studies. Finally, using evidence from literature and interactomics databanks, we infer ILKs-dependent cellular pathways and highlight their potential in transmitting multiple types of signals originating at the interface between the cell wall and plasma membrane.
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Affiliation(s)
- Sorina C. Popescu
- Department of Biochemistry, Molecular Biology, Plant Pathology, and Entomology, Mississippi State University, StarkvilleMS, USA
| | - Elizabeth K. Brauer
- Ottawa Research and Development Center, Agriculture and Agri-Food Canada, OttawaON, Canada
| | - Gizem Dimlioglu
- Department of Biochemistry, Molecular Biology, Plant Pathology, and Entomology, Mississippi State University, StarkvilleMS, USA
| | - George V. Popescu
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, StarkvilleMS, USA
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Kosentka PZ, Zhang L, Simon YA, Satpathy B, Maradiaga R, Mitoubsi O, Shpak ED. Identification of critical functional residues of receptor-like kinase ERECTA. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:1507-1518. [PMID: 28207053 PMCID: PMC5441908 DOI: 10.1093/jxb/erx022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In plants, extracellular signals are primarily sensed by plasma membrane-localized receptor-like kinases (RLKs). ERECTA is a leucine-rich repeat RLK that together with its paralogs ERECTA-like 1 (ERL1) and ERL2 regulates multiple aspects of plant development. ERECTA forms complexes with a range of co-receptors and senses secreted cysteine-rich small proteins from the EPF/EPFL family. Currently the mechanism of the cytoplasmic domain activation and transmission of the signal by ERECTA is unclear. To gain a better understanding we performed a structure-function analysis by introducing altered ERECTA genes into erecta and erecta erl1 erl2 mutants. These experiments indicated that ERECTA's ability to phosphorylate is functionally significant, and that while the cytoplasmic juxtamembrane domain is important for ERECTA function, the C-terminal tail is not. An analysis of multiple putative phosphorylation sites identified four amino acids in the activation segment of the kinase domain as functionally important. Homology of those residues to functionally significant amino acids in multiple other plant RLKs emphasizes similarities in RLK function. Specifically, our data predicts Thr812 as a primary site of phosphor-activation and potential inhibitory phosphorylation of Tyr815 and Tyr820. In addition, our experiments suggest that there are differences in the molecular mechanism of ERECTA function during regulation of stomata development and in elongation of above-ground organs.
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Affiliation(s)
- Pawel Z Kosentka
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Liang Zhang
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Yonas A Simon
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Binita Satpathy
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Richard Maradiaga
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Omar Mitoubsi
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Elena D Shpak
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
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14
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Kaufmann C, Motzkus M, Sauter M. Phosphorylation of the phytosulfokine peptide receptor PSKR1 controls receptor activity. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:1411-1423. [PMID: 28338789 PMCID: PMC5441923 DOI: 10.1093/jxb/erx030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The phytosulfokine peptide receptor PSKR1 is modified by phosphorylation of its cytoplasmic kinase domain. We analyzed defined phosphorylation sites by site-directed mutagenesis with regard to kinase activity in vitro and receptor activity in planta. S696 and S698 in the juxtamembrane (JM) domain are phosphorylated in planta. The phosphomimetic S696D/S698D replacements resulted in reduced transphosphorylation activity of PSKR1 kinase in vitro but did not reduce autophosphorylation activity. Growth-promoting activity of the PSKR1(S696D/S698D) receptor isoform was impaired in the shoot but not in the root. The JM domain thus seems to be important for phosphorylation of a target protein required for shoot growth promotion. The phosphomimetic replacement T998D at the C-terminus (CT) abolished kinase activity in vitro but not receptor function in planta, indicating that additional levels of regulation exist in planta. A possible mode of receptor regulation is the interaction with regulatory proteins such as the calcium sensor calmodulin (CaM). We show that the previously reported binding of CaM2 to PSKR1 is calcium-dependent, occurs predominately to the hypophosphorylated soluble PSKR1 kinase, and does not significantly change PSKR1 kinase activity. In conclusion, our results show that peptide signaling of growth by PSKR1 is regulated by differential phosphorylation of the juxtamembrane and C-terminal domains of the intracellular receptor part and suggest that interaction of PSKR1 with CaM serves a function other than the regulation of kinase activity.
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Affiliation(s)
- Christine Kaufmann
- Entwicklungsbiologie und Physiologie der Pflanzen, Christian-Albrechts-Universität Kiel, Am Botanischen Garten 5, 24118 Kiel, Germany
| | - Michael Motzkus
- Entwicklungsbiologie und Physiologie der Pflanzen, Christian-Albrechts-Universität Kiel, Am Botanischen Garten 5, 24118 Kiel, Germany
| | - Margret Sauter
- Entwicklungsbiologie und Physiologie der Pflanzen, Christian-Albrechts-Universität Kiel, Am Botanischen Garten 5, 24118 Kiel, Germany
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15
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Phosphorylation of the dimeric cytoplasmic domain of the phytosulfokine receptor, PSKR1. Biochem J 2016; 473:3081-98. [PMID: 27487840 DOI: 10.1042/bcj20160593] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/03/2016] [Indexed: 11/17/2022]
Abstract
Phytosulfokines (PSKs) are plant peptide hormones that co-regulate plant growth, differentiation and defense responses. PSKs signal through a plasma membrane localized leucine-rich repeat receptor-like kinase (phytosulfokine receptor 1, PSKR1) that also contains a functional cytosolic guanylate cyclase with its cyclase catalytic center embedded within the kinase domain. To functionally characterize this novel type of overlapping dual catalytic function, we investigated the phosphorylation of PSKR1 in vitro Tandem mass spectrometry of the cytoplasmic domain of PSKR1 (PSKR1cd) revealed at least 11 phosphorylation sites (8 serines, 2 threonines and 1 tyrosine) within the PSKR1cd. Phosphomimetic mutations of three serine residues (Ser686, Ser696 and Ser698) in tandem at the juxta-membrane position resulted in enhanced kinase activity in the on-mutant that was suppressed in the off-mutant, but both mutations reduced guanylate cyclase activity. Both the on and off phosphomimetic mutations of the phosphotyrosine (Tyr888) residue in the activation loop suppressed kinase activity, while neither mutation affected guanylate cyclase activity. Size exclusion and analytical ultracentrifugation analysis of the PSKR1cd suggest that it is reversibly dimeric in solution, which was further confirmed by biflourescence complementation. Taken together, these data suggest that in this novel type of receptor domain architecture, specific phosphorylation and dimerization are possibly essential mechanisms for ligand-mediated catalysis and signaling.
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