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Bao Y, Zhang Q, Zhu H, Pei Y, Zhao Y, Li Y, Ji P, Du D, Peng H, Xu G, Wang X, Yin Z, Ai G, Liang X, Dou D. Metformin blocks BIK1-mediated CPK28 phosphorylation and enhances plant immunity. J Adv Res 2024:S2090-1232(24)00087-0. [PMID: 38442853 DOI: 10.1016/j.jare.2024.02.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 03/07/2024] Open
Abstract
INTRODUCTION Metformin (MET), derived from Galega officinalis, stands as the primary first-line medication for the treatment of type 2 diabetes (T2D). Despite its well-documented benefits in mammalian cellular processes, its functions and underlying mechanisms in plants remain unclear. OBJECTIVES This study aimed to elucidate MET's role in inducing plant immunity and investigate the associated mechanisms. METHODS To investigate the impact of MET on enhancing plant immune responses, we conducted assays measuring defense gene expression, reactive oxygen species (ROS) accumulation, mitogen-activated protein kinase (MAPK) phosphorylation, and pathogen infection. Additionally, surface plasmon resonance (SPR) and microscale thermophoresis (MST) techniques were employed to identify MET targets. Protein-protein interactions were analyzed using a luciferase complementation assay and a co-immunoprecipitation assay. RESULTS Our findings revealed that MET boosts plant disease resistance by activating MAPKs, upregulating the expression of downstream defense genes, and fortifying the ROS burst. CALCIUM-DEPENDENT PROTEIN KINASE 28 (CPK28) was identified as a target of MET. It inhibited the interaction between BOTRYTIS-INDUCED KINASE 1 (BIK1) and CPK28, blocking CPK28 threonine 76 (T76) transphosphorylation by BIK1, and alleviating the negative regulation of immune responses by CPK28. Moreover, MET enhanced disease resistance in tomato, pepper, and soybean plants. CONCLUSION Collectively, our data suggest that MET enhances plant immunity by blocking BIK1-mediated CPK28 phosphorylation.
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Affiliation(s)
- Yazhou Bao
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China; College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Qian Zhang
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Hai Zhu
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Yong Pei
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Yaning Zhao
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Yixin Li
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Peiyun Ji
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Dandan Du
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Hao Peng
- USDA Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648, USA
| | - Guangyuan Xu
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Xiaodan Wang
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Zhiyuan Yin
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Gan Ai
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiangxiu Liang
- College of Plant Protection, China Agricultural University, Beijing 100193, China; College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
| | - Daolong Dou
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China; College of Plant Protection, China Agricultural University, Beijing 100193, China.
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Diao Y, Yao Y, El-Ashram S, Bian M. Egress Regulatory Factors: How Toxoplasma Exits from Infected Cells? Pathogens 2023; 12:pathogens12050679. [PMID: 37242349 DOI: 10.3390/pathogens12050679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023] Open
Abstract
Toxoplasma gondii is an obligatory intracellular protozoan in the family Apicomplexa. It infects almost one-third of the world's population and causes toxoplasmosis, a prevalent disease. The parasite's egress from infected cells is a key step in the pathology caused by T. gondii. Moreover, T. gondii's continuous infection relies heavily on its capacity to migrate from one cell to another. Many pathways are involved in T. gondii egress. Individual routes may be modified to respond to various environmental stimuli, and many paths can converge. Regardless of the stimuli, the relevance of Ca2+ as a second messenger in transducing these signals, and the convergence of various signaling pathways in the control of motility and, ultimately, egress, is well recognized. This review attempts to outline intra- and extra-parasitic regulators that mediate T. gondii egress, and provides insight into potential clinical interventions and research.
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Affiliation(s)
- Yujie Diao
- Department of Blood Transfusion, The First Affiliated Hospital of Anhui Medical University, Hefei 230032, China
| | - Yong Yao
- College of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Saeed El-Ashram
- College of Life Science and Engineering, Foshan University, 18 Jiangwan Street, Foshan 528231, China
- Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt
| | - Maohong Bian
- Department of Blood Transfusion, The First Affiliated Hospital of Anhui Medical University, Hefei 230032, China
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Elsworth B, Keroack C, Rezvani Y, Paul A, Barazorda K, Tennessen J, Sack S, Moreira C, Gubbels MJ, Meyers M, Zarringhalam K, Duraisingh M. Babesia divergens egress from host cells is orchestrated by essential and druggable kinases and proteases. RESEARCH SQUARE 2023:rs.3.rs-2553721. [PMID: 36909484 PMCID: PMC10002801 DOI: 10.21203/rs.3.rs-2553721/v1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Apicomplexan egress from host cells is fundamental to the spread of infection and is poorly characterized in Babesia spp., parasites of veterinary importance and emerging zoonoses. Through the use of video microscopy, transcriptomics and chemical genetics, we have implicated signaling, proteases and gliding motility as key drivers of egress by Babesia divergens. We developed reverse genetics to perform a knockdown screen of putative mediators of egress, identifying kinases and proteases involved in distinct steps of egress (ASP3, PKG and CDPK4) and invasion (ASP2, ASP3 and PKG). Inhibition of egress leads to continued intracellular replication, indicating exit from the replication cycle is uncoupled from egress. Chemical genetics validated PKG, ASP2 and ASP3 as druggable targets in Babesia spp. All taken together, egress in B. divergens more closely resembles T. gondii than the more evolutionarily-related Plasmodium spp. We have established a molecular framework for biological and translational studies of B. divergens egress.
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Bredow M, Monaghan J. Cross-kingdom regulation of calcium- and/or calmodulin-dependent protein kinases by phospho-switches that relieve autoinhibition. CURRENT OPINION IN PLANT BIOLOGY 2022; 68:102251. [PMID: 35767936 DOI: 10.1016/j.pbi.2022.102251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/04/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Mechanisms to sense and respond to calcium have evolved in all organisms. Calmodulin is a universal calcium sensor across eukaryotes that directly binds calcium and associates with many downstream signal transducers including protein kinases. All eukaryotes encode calcium-dependent and/or calmodulin-dependent kinases, however there are distinct protein families across kingdoms. Here, we compare the activation mechanisms of calmodulin-dependent protein kinases (CaMKs), calcium- and calmodulin-dependent protein kinases (CCaMKs) and calcium-dependent protein kinases (CDPKs), noting striking similarities regarding phosphorylation in a regulatory segment known as the autoinhibitory junction. We thus propose that conserved regulation by phosphorylation underlies the activation of calcium-responsive proteins from different kingdoms.
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Affiliation(s)
- Melissa Bredow
- Department of Plant Pathology and Microbiology, Iowa State University, Ames IA, USA.
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Gupta P, Mohanty D. Allosteric regulation of the inactive to active state conformational transition in CDPK1 protein of Plasmodium falciparum. Int J Biol Macromol 2022; 215:489-500. [PMID: 35709874 DOI: 10.1016/j.ijbiomac.2022.06.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/05/2022] [Accepted: 06/10/2022] [Indexed: 11/05/2022]
Abstract
The aim of the current study is to investigate the role of the CAD domain in the activation mechanism of calcium dependent protein kinase-1 of Plasmodium falciparum (PfCDPK1) and explore the possibility of allosteric inhibition of this kinase. PfCDPK1 belongs to CDPK family of apicomplexan kinases which have a C-terminal CAD domain. Microsecond scale MD simulations were performed on modeled structures of complete PfCDPK1 and its kinase domain alone. The simulations revealed that in absence of CAD the salt bridge between Glu116 in αC-helix and Lys85 in β3-sheet of kinase breaks after 200 ns resulting in inactive conformation of the kinase, but the salt bridge stays intact in the complete protein stabilizing it in active conformation. These results highlight the novel CAD mediated allosteric stabilization of the crucial salt bridge which is a hallmark of active conformation of kinase domains. The mechanistic details of the allosteric activation revealed by our study, opens up the possibility for design of allosteric inhibitors of PfCDPK1 kinase by disrupting the kinase:CAD interactions. Using a combination of machine learning and structure-based in silico screening, we have identified novel PPI modulators for allosteric inactivation of PfCDPK1 kinase.
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Affiliation(s)
- Priya Gupta
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Debasisa Mohanty
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India.
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