scholarly journals The Arabidopsis homolog of human G3BP1 is a key regulator of stomatal and apoplastic immunity

2018 ◽  
Vol 1 (2) ◽  
pp. e201800046 ◽  
Author(s):  
Aala A Abulfaraj ◽  
Kiruthiga Mariappan ◽  
Jean Bigeard ◽  
Prabhu Manickam ◽  
Ikram Blilou ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Plant Immunity ◽  
Bacterial Pathogen ◽  
Defense Responses ◽  
Pathogen Resistance ◽  
Negative Regulator ◽  
Multifunctional Protein

Mammalian Ras-GTPase–activating protein SH3-domain–binding proteins (G3BPs) are a highly conserved family of RNA-binding proteins that link kinase receptor-mediated signaling to RNA metabolism. Mammalian G3BP1 is a multifunctional protein that functions in viral immunity. Here, we show that the Arabidopsis thaliana homolog of human G3BP1 negatively regulates plant immunity. Arabidopsis g3bp1 mutants showed enhanced resistance to the virulent bacterial pathogen Pseudomonas syringae pv. tomato. Pathogen resistance was mediated in Atg3bp1 mutants by altered stomatal and apoplastic immunity. Atg3bp1 mutants restricted pathogen entry into stomates showing insensitivity to bacterial coronatine–mediated stomatal reopening. AtG3BP1 was identified as a negative regulator of defense responses, which correlated with moderate up-regulation of salicylic acid biosynthesis and signaling without growth penalty.

scholarly journals Plant defense responses against viral and bacterial pathogen infections. Focus on RNA-binding proteins (RBPs)

2015 ◽  
Vol 60 (4) ◽  
pp. 60-73
Author(s):  
Musidlak Oskar ◽  
Waldemar Buchwald ◽  
Robert Nawrot
Keyword(s):  
Medicinal Plants ◽  
Defense Mechanisms ◽  
Binding Proteins ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Plant Immunity ◽  
Bacterial Pathogen ◽  
Defense Responses ◽  
Chelidonium Majus

SummaryPlants have developed intricate defense mechanisms against pathogen infections. Immune system of medicinal plants is well developed. The molecular mechanisms of their ability to protect themselves are not fully understood. Little is known about RNA-binding proteins (RBPs) present in medicinal plants. However, CmGRP1 is an RBP found in the milky sap of medicinal plant Chelidonium majus L. what implies possible importance of RBPs in plant immunity. In this review recent insights into the role of plant RBPs in antiviral and antibacterial defense responses are discussed.

A type III effector ADP-ribosylates RNA-binding proteins and quells plant immunity

Nature ◽  
2007 ◽  
Vol 447 (7142) ◽  
pp. 284-288 ◽  
Author(s):  
Zheng Qing Fu ◽  
Ming Guo ◽  
Byeong-ryool Jeong ◽  
Fang Tian ◽  
Thomas E. Elthon ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Plant Immunity ◽  
Type Iii Effector ◽  
Type Iii

scholarly journals Analysis of Resistance Gene-Mediated Defense Responses in Arabidopsis thaliana Plants Carrying a Mutation in CPR5

1998 ◽  
Vol 11 (12) ◽  
pp. 1196-1206 ◽  
Author(s):  
Jens Boch ◽  
Michelle L. Verbsky ◽  
Tara L. Robertson ◽  
John C. Larkin ◽  
Barbara N. Kunkel
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Resistance Gene ◽  
Pseudomonas Syringae ◽  
Bacterial Pathogen ◽  
Defense Responses ◽  
Negative Regulator ◽  
Suppressor Mutations ◽  
Defense Related Gene ◽  
Rapid Activation

In resistant plants, pathogen attack often leads to rapid activation of defense responses that limit multiplication and spread of the pathogen. To investigate the signaling mechanisms underlying this process, we carried out a screen for mutants in the signaling pathway governing resistance in Arabidopsis thaliana to the bacterial pathogen Pseudomonas syringae. This involved screening for suppressor mutations that restored resistance to a susceptible line carrying a mutation in the RPS2 resistance gene. A mutant that conferred resistance by activating defense responses in the absence of pathogens was isolated. This mutant, which carries a mutation at the CPR5 locus and was thus designated cpr5-2, exhibited resistance to P. syringae, spontaneous development of necrotic lesions, elevated PR gene expression in the absence of pathogens, and abnormal trichomes. Resistance gene-mediated defenses, including the hypersensitive response, restriction of pathogen growth, and induction of defense-related gene expression, were functional in cpr5-2 mutant plants. Additionally, in cpr5-2 plants RPS2-mediated induction of PR-1 expression was enhanced, whereas RPM1-mediated induction of ELI3 was not. These findings suggest that CPR5 encodes a negative regulator of the RPS2 signal transduc-tion pathway.

scholarly journals A novel Phytophthora sojae effector PsFYVE1 modulates transcription and alternative splicing of immunity related genes by targeting host RZ-1A protein

2021 ◽  
Author(s):  
Xinyu Lu ◽  
Zitong Yang ◽  
Wen Song ◽  
Jierui Si ◽  
Zhiyuan Yin ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Binding Proteins ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Plant Immunity ◽  
Phytophthora Sojae ◽  
Protein Family ◽  
Plant Interactions ◽  
Fyve Domain

AbstractOomycete pathogens secrete many effectors to manipulate plant immunity and promote infection. However, relatively few effector types have been well characterized. In this study, members of a FYVE domain-containing protein family that is highly expanded in oomycetes were systematically identified, and one secreted protein, PsFYVE1, was selected for further study. PsFYVE1 enhanced Phytophthora infection in Nicotiana benthamiana and was necessary for P. sojae virulence. The FYVE domain of PsFYVE1 had PI3P-binding activity that depended on four conservative amino acid residues. Furthermore, PsFYVE1 targeted RNA-binding proteins RZ-1A/1B/1C in N. benthamiana and soybean, and silencing of NbRZ-1A/1B/1C genes attenuates plant immunity. NbRZ-1A was associated with spliceosome that included three important components, NbGRP7, NbGRP8, and NbU1-70K. Notably, PsFYVE1 could disrupt NbRZ-1A–NbGRP7 interaction. RNA-seq and subsequent experimental analysis demonstrated that PsFYVE1 and NbRZ-1A not only co-regulated transcription of NbHCT, NbEIN2, and NbSUS4 genes but also modulated pre-mRNA alternative splicing (AS) of the NbNSL1 gene, which participated in plant immunity. Collectively, these findings indicate that the FYVE domain-containing protein family includes potential new effector types and also highlight that plant pathogen effectors can regulate plant immunity related genes at both transcription and AS levels to promote disease.Author summaryMany plant pathogenic oomycetes secrete effector proteins into plants to facilitate infection. Discovering potential repertoire of novel effectors and corresponding molecular mechanisms are major themes in the study of oomycete–plant interactions. Here, we characterized a FYVE domain-containing protein (PsFYVE1) in P. sojae. PsFYVE1 carries a functional secretory signal peptide and is a virulence-essential effector for P. sojae infection. We demonstrated that PsFYVE1 interacted with a class of plant RNA-binding proteins, including soybean GmRZ-1A/1B/1C and N. benthamiana NbRZ-1A/1B/1C. Silencing of NbRZ-1A/1B/1C proteins increased Phytophthora infection and suppressed plant defense. Furthermore, NbRZ-1A interacted with the spliceosome components, and PsFYVE1 disrupted association between NbRZ-1A and spliceosome component NbGRP7. We examined the global transcription and alternative splicing (AS) changes regulated by PsFYVE1 and NbRZ-1A, which indicated that PsFYVE1 and NbRZ-1A co-regulated transcription and pre-mRNA AS of immunity-related genes. Thus, this study identifies a novel virulence-related effector from P. sojae and a class of positive regulators of plant immunity, and reveals a detailed mechanism of effector-medicated transcription and AS regulation during pathogen–plant interactions.

scholarly journals Calreticulin Interacts with C/EBPα and C/EBPβ mRNAs and Represses Translation of C/EBP Proteins

2002 ◽  
Vol 22 (20) ◽  
pp. 7242-7257 ◽  
Author(s):  
Lubov T. Timchenko ◽  
Polina Iakova ◽  
Alana L. Welm ◽  
Z.-J. Cai ◽  
Nikolai A. Timchenko
Keyword(s):  
Rna Processing ◽  
Posttranscriptional Regulation ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Posttranscriptional Control ◽  
Multifunctional Protein ◽  
Virus Rna

ABSTRACT We previously identified an RNA binding protein, CUGBP1, which binds to GCN repeats located within the 5′ region of C/EBPβ mRNAs and regulates translation of C/EBPβ isoforms. To further investigate the role of RNA binding proteins in the posttranscriptional control of C/EBP proteins, we purified additional RNA binding proteins that interact with GC-rich RNAs and that may regulate RNA processing. In HeLa cells, the majority of GC-rich RNA binding proteins are associated with endogenous RNA transcripts. The separation of these proteins from endogenous RNA identified several proteins in addition to CUGBP1 that specifically interact with the GC-rich 5′ region of C/EBPβ mRNA. One of these proteins was purified to homogeneity and was identified as calreticulin (CRT). CRT is a multifunctional protein involved in several biological processes, including interaction with and regulation of rubella virus RNA processing. Our data demonstrate that both CUGBP1 and CRT interact with GCU repeats within myotonin protein kinase and with GCN repeats within C/EBPα and C/EBPβ mRNAs. GCN repeats within these mRNAs form stable SL structures. The interaction of CRT with SL structures of C/EBPβ and C/EBPα mRNAs leads to inhibition of translation of C/EBP proteins in vitro and in vivo. Deletions or mutations abolishing the formation of SL structures within C/EBPα and C/EBPβ mRNAs lead to a failure of CRT to inhibit translation of C/EBP proteins. CRT-dependent inhibition of C/EBPα is sufficient to block the growth-inhibitory activity of C/EBPα. This finding further defines the molecular mechanism for posttranscriptional regulation of the C/EBPα and C/EBPβ proteins.

scholarly journals AtMC1 associates with LSM4 to regulate plant immunity through modulating pre-mRNA splicing

2021 ◽  
Author(s):  
Shune Wang ◽  
Mei Xue ◽  
Chan He ◽  
Danyu Shen ◽  
Chunhao Jiang ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Immunity ◽  
Bacterial Pathogen ◽  
Mrna Splicing ◽  
Negative Regulator ◽  
Type I ◽  
Rna Seq ◽  
Protein Levels ◽  
Gene Regulatory

Alternative splicing (AS) of pre-mRNAs is an important gene regulatory mechanism shaping the transcriptome. AtMC1 is an Arabidopsis thaliana type I metacaspase that positively regulates hypersensitive response. Here, we found that AtMC1 is involved in the regulation of plant immunity to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000 and is physically associated with Sm-like4 (LSM4), which is involved in pre-mRNA splicing. AtMC1 and LSM4 protein levels both increased with their co-expression as compared with their separate expression in vivo. LSM4 negatively regulates plant immunity to Pst DC3000 infection. By RNA-seq, AtMC1 was shown to modulate the splicing of many pre-mRNAs including 4CL3, which is a negative regulator of plant immunity. Thus, AtMC1 plays a regulatory role in pre-mRNA splicing, which might contribute to AtMC1-mediated plant immunity.

scholarly journals Grad-seq guides the discovery of ProQ as a major small RNA-binding protein

2016 ◽  
Vol 113 (41) ◽  
pp. 11591-11596 ◽  
Author(s):  
Alexandre Smirnov ◽  
Konrad U. Förstner ◽  
Erik Holmqvist ◽  
Andreas Otto ◽  
Regina Günster ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Noncoding Rna ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Bacterial Pathogen ◽  
Wide Range ◽  
Functional Rna

The functional annotation of transcriptomes and identification of noncoding RNA (ncRNA) classes has been greatly facilitated by the advent of next-generation RNA sequencing which, by reading the nucleotide order of transcripts, theoretically allows the rapid profiling of all transcripts in a cell. However, primary sequence per se is a poor predictor of function, as ncRNAs dramatically vary in length and structure and often lack identifiable motifs. Therefore, to visualize an informative RNA landscape of organisms with potentially new RNA biology that are emerging from microbiome and environmental studies requires the use of more functionally relevant criteria. One such criterion is the association of RNAs with functionally important cognate RNA-binding proteins. Here we analyze the full ensemble of cellular RNAs using gradient profiling by sequencing (Grad-seq) in the bacterial pathogenSalmonella enterica, partitioning its coding and noncoding transcripts based on their network of RNA–protein interactions. In addition to capturing established RNA classes based on their biochemical profiles, the Grad-seq approach enabled the discovery of an overlooked large collective of structured small RNAs that form stable complexes with the conserved protein ProQ. We show that ProQ is an abundant RNA-binding protein with a wide range of ligands and a global influence onSalmonellagene expression. Given its generic ability to chart a functional RNA landscape irrespective of transcript length and sequence diversity, Grad-seq promises to define functional RNA classes and major RNA-binding proteins in both model species and genetically intractable organisms.

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