scholarly journals Inactivation of SGS3 as Molecular Basis for RNA Silencing Suppression by TYLCV V2

2013 ◽  
Author(s):  
Yedidya Gafni ◽  
Vitaly Citovsky
Keyword(s):  
Rna Silencing ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Plant Immunity ◽  
Inhibitory Effect ◽  
Binding Activity ◽  
Plant Interactions ◽  
Subsequent Conversion ◽  
Tomato Pathogen ◽  
F Box Protein

The Israeli isolate of Tomato yellow leaf curl geminivirus(TYLCV-Is) is a major tomato pathogen, causing extensive crop losses in Israel and in the south-eastern U.S. Yet, little is known about the molecular mechanisms of its interaction with tomato cells. One of the most interesting aspects of such interaction is how the invading virus counteracts the RNA silencing response of the plant. In the former BARD project, we have shown that TYLCV-Is V2 protein is an RNA silencing suppressor, and that this suppression is carried out via the interaction of V2 with the SGS3 component of the plant RNA silencing machinery. This reported project was meant to use our data as a foundation to elucidate the molecular mechanism by which V2 affects the SGS3 activity. While this research is likely to have an important impact on our understanding of basic biology of virus-plant interactions and suppression of plant immunity, it also will have practical implications, helping to conceive novel strategies for crop resistance to TYLCV-Is. Our preliminary data in regard to V2 activities and our present knowledge of the SGS3 function suggest likely mechanisms for the inhibitory effect of V2 on SGS3. We have shown that V2 possess structural and functional hallmarks of an F-box protein, suggesting that it may target SGS3 for proteasomal degradation. SGS3 contains an RNA-binding domain and likely functions to protect the cleavage produces of the primary transcript for subsequent conversion to double-stranded forms; thus, V2 may simply block the RNA binding activity of SGS3. V2 may also employ a combination of these mechanisms. These and other possibilities were tested in this reported project. 

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 Suppression of RNA Silencing by TYLCV During Viral Infection

2009 ◽  
Author(s):  
Vitaly Citovsky ◽  
Yedidya Gafni
Keyword(s):  
Rna Silencing ◽  
Molecular Mechanisms ◽  
Protein S ◽  
Viral Agent ◽  
Tomato Plants ◽  
Research Findings ◽  
Tomato Pathogen ◽  
F Box Protein ◽  
Suppressor Of Rna Silencing

The Israeli isolate of Tomato yellow leaf curl geminivirus (TYLCV-Is) is a major tomato pathogen, causing extensive (up to 100%) crop losses in Israel and in the south-eastern U.S. (e.g., Georgia, Florida). Surprisingly, however, little is known about the molecular mechanisms of TYLCV-Is interactions with tomato cells. In the current BARD project, we have identified a TYLCV-Is protein, V2, which acts as a suppressor of RNA silencing, and showed that V2 interacts with the tomato (L. esculentum) member of the SGS3 (LeSGS3) protein family known to be involved in RNA silencing. This proposal will use our data as a foundation to study one of the most intriguing, yet poorly understood, aspects of TYLCV-Is interactions with its host plants – possible involvement of the host innate immune system, i.e., RNA silencing, in plant defense against TYLCV-Is and the molecular pathway(s) by which TYLCV-Is may counter this defense. Our project sought two objectives: I. Study of the roles of RNA silencing and its suppression by V2 in TYLCV-Is infection of tomato plants. II. Study of the mechanism by which V2 suppresses RNA silencing. Our research towards these goals has produced the following main achievements: • Identification and characterization of TYLCV V2 protein as a suppressor of RNA silencing. (#1 in the list of publications). • Characterization of the V2 protein as a cytoplasmic protein interacting with the plant protein SlSGS3 and localized mainly in specific, not yet identified, bodies. (#2 in the list of publications). • Development of new tools to study subcellular localization of interacting proteins (#3 in the list of publications). • Characterization of TYLCV V2 as a F-BOX protein and its possible role in target protein(s) degradation. • Characterization of TYLCV V2 interaction with a tomato cystein protease that acts as an anti-viral agent. These research findings provided significant insights into (I) the suppression of RNA silencing executed by the TYLCV V2 protein and (II) characterization some parts of the mechanism(s) involved in this suppression. The obtained knowledge will help to develop specific strategies to attenuate TYLCV infection, for example, by blocking the activity of the viral suppressor of gene silencing thus enabling the host cell silencing machinery combat the virus.

scholarly journals LINC00899 promotes osteogenic differentiation and alleviates osteoporosis via targeting miR-374a to regulate RUNX2

2020 ◽  
Author(s):  
Xiaoya Gao ◽  
Yun Xue ◽  
Kechun Yang
Keyword(s):  
Osteogenic Differentiation ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Quantitative Polymerase Chain Reaction ◽  
Direct Interaction ◽  
Inhibitory Effect ◽  
Luciferase Reporter ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red ◽  
Osteogenic Induction

Abstract Objective: This study aims to illustrate the underlying molecular mechanisms of long noncoding RNAs (LncRNAs) LINC00899 in osteoporosis.Methods: Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was used to examine the levels of LINC00899, miR-374a and RUNX2 in clinical tissues or human bone mesenchymal stem cells (hBMSCs). The interaction between miR-374a and LINC00899 or RUNX2 was predicted by starBase and verified by luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay. Alkaline phosphatase (ALP) activity and Alizarin Red S (ARS) staining were also used to evaluate the osteogenic ability of hBMSCs.Results: The expression levels of LINC00899 were gradually increased, but miR-374a expression was decreased with the prolongation of osteogenic induction. In addition, the expression of LINC00899 was lowly expressed in osteoporotic patients’ bone tissues and knockdown of LINC00899 decreased the expression of osteogenesis-related genes. Moreover, LINC00899 was confirmed to inhibit miR-374a expression by direct interaction. Finally, we demonstrated that RUNX2 was a target of miR-374a, and the silencing of miR-374a partially abolished the inhibitory effect of LINC00899 knockdown on the expression of RUNX2, OPN and OCN.Conclusions: We demonstrated that LINC00899 facilitated the osteogenic differentiation of hBMSCs and prevented osteoporosis by sponging miR-374a and enhancing RUNX2 expression, which might provide a useful therapeutic strategy for osteoporosis patients.

scholarly journals LINC00899 Promotes Osteogenic Differentiation and Alleviates Osteoporosis via Targeting miR-374a to Regulate RUNX2

2020 ◽  
Author(s):  
Xiaoya Gao ◽  
Yun Xue ◽  
Kechun Yang
Keyword(s):  
Osteogenic Differentiation ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Quantitative Polymerase Chain Reaction ◽  
Direct Interaction ◽  
Inhibitory Effect ◽  
Luciferase Reporter ◽  
Bone Mesenchymal Stem Cells ◽  
Osteogenic Induction ◽  
Rip Assay

Abstract Objective: This study aims to illustrate the underlying molecular mechanisms of long noncoding RNAs (LncRNAs) LINC00899 in osteoporosis.Methods: Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) used to examine the levels of LINC00899, miR-374a and RUNX2 in clinical tissues or human bone mesenchymal stem cells (hBMSCs). The interaction between miR-374a and LINC00899 or RUNX2 was predicted by starBase and verified by luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay. Results: The expression of LINC00899 was lowly expressed in osteoporotic patients’ bone tissues and knockdown of LINC00899 decreased the expression of osteogenesis-related genes. Moreover, LINC00899 was confirmed to inhibit miR-374a expression by direct interaction. the expression levels of LINC00899 were gradually increased, but miR-374a expression was decreased with the prolongation of osteogenic induction. Finally, we demonstrated that RUNX2 was a target of miR-374a, and the silencing of miR-374a partially abolished the inhibitory effect of LINC00899 knockdown on the expression of RUNX2, OPN and OCN.Conclusions: We demonstrated that LINC00899 facilitated osteogenic differentiation of hBMSCs and prevent osteoporosis by sponging miR-374a and enhancing RUNX2 expression, which might provide a useful therapeutic strategy for osteoporosis patients.

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.

scholarly journals SARS-CoV-2 N Protein Targets TRIM25-Mediated RIG-I Activation to Suppress Innate Immunity

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1439
Author(s):  
Gianni Gori Savellini ◽  
Gabriele Anichini ◽  
Claudia Gandolfo ◽  
Maria Grazia Cusi
Keyword(s):  
Molecular Mechanisms ◽  
Rna Binding ◽  
Antagonistic Activity ◽  
Binding Activity ◽  
Host Immune System ◽  
The Novel ◽  
Protein Targets ◽  
N Protein ◽  
New Findings ◽  
Severe Clinical Picture

A weak production of INF-β along with an exacerbated release of pro-inflammatory cytokines have been reported during infection by the novel SARS-CoV-2 virus. SARS-CoV-2 encodes several proteins able to counteract the host immune system, which is believed to be one of the most important features contributing to the viral pathogenesis and development of a severe clinical picture. Previous reports have demonstrated that SARS-CoV-2 N protein, along with some non-structural and accessory proteins, efficiently suppresses INF-β production by interacting with RIG-I, an important pattern recognition receptor (PRR) involved in the recognition of pathogen-derived molecules. In the present study, we better characterized the mechanism by which the SARS-CoV-2 N counteracts INF-β secretion and affects RIG-I signaling pathways. In detail, when the N protein was ectopically expressed, we noted a marked decrease in TRIM25-mediated RIG-I activation. The capability of the N protein to bind to, and probably mask, TRIM25 could be the consequence of its antagonistic activity. Furthermore, this interaction occurred at the SPRY domain of TRIM25, harboring the RNA-binding activity necessary for TRIM25 self-activation. Here, we describe new findings regarding the interplay between SARS-CoV-2 and the IFN system, filling some gaps for a better understanding of the molecular mechanisms affecting the innate immune response in COVID-19.

NOB1: A Potential Biomarker or Target in Cancer

2019 ◽  
Vol 20 (10) ◽  
pp. 1081-1089
Author(s):  
Weiwei Ke ◽  
Zaiming Lu ◽  
Xiangxuan Zhao
Keyword(s):  
Cancer Treatment ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Binding Protein ◽  
Tumor Development ◽  
Anticancer Therapy ◽  
Research Progress ◽  
Normal Tissues ◽  
Potential Biomarker

Human NIN1/RPN12 binding protein 1 homolog (NOB1), an RNA binding protein, is expressed ubiquitously in normal tissues such as the lung, liver, and spleen. Its core physiological function is to regulate protease activities and participate in maintaining RNA metabolism and stability. NOB1 is overexpressed in a variety of cancers, including pancreatic cancer, non-small cell lung cancer, ovarian cancer, prostate carcinoma, osteosarcoma, papillary thyroid carcinoma, colorectal cancer, and glioma. Although existing data indicate that NOB1 overexpression is associated with cancer growth, invasion, and poor prognosis, the molecular mechanisms behind these effects and its exact roles remain unclear. Several studies have confirmed that NOB1 is clinically relevant in different cancers, and further research at the molecular level will help evaluate the role of NOB1 in tumors. NOB1 has become an attractive target in anticancer therapy because it is overexpressed in many cancers and mediates different stages of tumor development. Elucidating the role of NOB1 in different signaling pathways as a potential cancer treatment will provide new ideas for existing cancer treatment methods. This review summarizes the research progress made into NOB1 in cancer in the past decade; this information provides valuable clues and theoretical guidance for future anticancer therapy by targeting NOB1.

Molecular Mechanisms of the Inhibitory Effects of Bupivacaine, Levobupivacaine, and Ropivacaine on Sarcolemmal Adenosine Triphosphate–sensitive Potassium Channels in the Cardiovascular System

2004 ◽  
Vol 101 (2) ◽  
pp. 390-398 ◽  
Author(s):  
Takashi Kawano ◽  
Shuzo Oshita ◽  
Akira Takahashi ◽  
Yasuo Tsutsumi ◽  
Yoshinobu Tomiyama ◽  
...  
Keyword(s):  
Cardiovascular System ◽  
Adenosine Triphosphate ◽  
Local Anesthetics ◽  
Molecular Mechanisms ◽  
Transmembrane Domain ◽  
Katp Channels ◽  
Inhibitory Effect ◽  
Amino Acid Residues ◽  
Sulfonylurea Receptor ◽  
Inhibitory Effects

Background Sarcolemmal adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system may be involved in bupivacaine-induced cardiovascular toxicity. The authors investigated the effects of local anesthetics on the activity of reconstituted KATP channels encoded by inwardly rectifying potassium channel (Kir6.0) and sulfonylurea receptor (SUR) subunits. Methods The authors used an inside-out patch clamp configuration to investigate the effects of bupivacaine, levobupivacaine, and ropivacaine on the activity of reconstituted KATP channels expressed in COS-7 cells and containing wild-type, mutant, or chimeric SURs. Results Bupivacaine inhibited the activities of cardiac KATP channels (IC50 = 52 microm) stereoselectively (levobupivacaine, IC50 = 168 microm; ropivacaine, IC50 = 249 microm). Local anesthetics also inhibited the activities of channels formed by the truncated isoform of Kir6.2 (Kir6.2 delta C36) stereoselectively. Mutations in the cytosolic end of the second transmembrane domain of Kir6.2 markedly decreased both the local anesthetics' affinity and stereoselectivity. The local anesthetics blocked cardiac KATP channels with approximately eightfold higher potency than vascular KATP channels; the potency depended on the SUR subtype. The 42 amino acid residues at the C-terminal tail of SUR2A, but not SUR1 or SUR2B, enhanced the inhibitory effect of bupivacaine on the Kir6.0 subunit. Conclusions Inhibitory effects of local anesthetics on KATP channels in the cardiovascular system are (1) stereoselective: bupivacaine was more potent than levobupivacaine and ropivacaine; and (2) tissue specific: local anesthetics blocked cardiac KATP channels more potently than vascular KATP channels, via the intracellular pore mouth of the Kir6.0 subunit and the 42 amino acids at the C-terminal tail of the SUR2A subunit, respectively.

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