scholarly journals Geminivirus C4 proteins inhibit GA signaling via prevention of NbGAI degradation, to promote viral infection and symptom development in N. benthamiana

2021 ◽  
Author(s):  
Pengbai Li ◽  
Liuming Guo ◽  
Xinyuan Lang ◽  
Mingjun Li ◽  
Gentu Wu ◽  
...  
Keyword(s):  
Viral Infection ◽  
Signaling Pathway ◽  
Protein A ◽  
26S Proteasome ◽  
Plant Responses ◽  
Plant Signaling ◽  
Symptom Development ◽  
Biotic Stresses ◽  
Ga Signaling ◽  
F Box Protein

Phytohormone gibberellin (GA) is an important plant signaling molecule that regulates plant growth and defense against abiotic and biotic stresses. To date, the molecular mechanism of the plant responses to viral infection mediated by GA is still undetermined. DELLA is a repressor of GA signaling and is recognized by the F-box protein, a component of the SCF SLY1/GID2 complex. The recognized DELLA is degraded by the ubiquitin-26S proteasome, leading to the activation of the GA signaling. Here, we report that ageratum leaf curl Sichuan virus (ALCScV)-infected N. benthamiana plants showed dwarfing symptom and abnormal flower development. The infection of ALCScV alters the expressions of GA pathway-related genes and decreases the content of endogenous GA significantly in N. benthamiana. Further, ALCScV-encoded C4 protein interacts with the DELLA protein NbGAI, and interferes with the interaction between NbGAI and NbGID2 to prevent the degradation of NbGAI, leading to the inhibition of the GA signaling pathway. Silencing of NbGAI or exogenous GA 3 treatment significantly reduces viral accumulation and disease symptoms in N. benthamiana plants. The same results were proved by the experiments with C4 protein encoded by tobacco curly shoot virus (TbCSV). Therefore, we propose a novel mechanism of geminivirus C4 proteins controling virus infection and disease symptom development through interfering GA signaling pathway.

scholarly journals Genome-wide survey of the F-box/Kelch (FBK) members and molecular identification of a novel FBK gene TaAFR in wheat

2021 ◽  
Author(s):  
Chunru Wei ◽  
Weiquan Zhao ◽  
Runqiao Fan ◽  
Yuyu Meng ◽  
Yiming Yang ◽  
...  
Keyword(s):  
Developmental Stages ◽  
In Silico Analysis ◽  
Digital Pcr ◽  
Plant Responses ◽  
Plant Signaling ◽  
Biotic Stresses ◽  
Genome Wide ◽  
Cereal Species ◽  
A Genome ◽  
Genome Wide Survey

F-box proteins play critical roles in plant responses to biotic/abiotic stresses. In the present study, a total of 68 wheat F-box/Kelch ( TaFBK ) gene sequences encoding for 74 proteins were obtained in a genome-wide survey against EnsemblPlants. The 74 TaFBK proteins were divided into 5 categories based on their domain structures. The FBK proteins from wheat, Arabidopsis, and three other cereal species were grouped into 7 clades, and the number of Kelch domains present was their key clustering criterion. Sixty-eight TaFBK genes were unevenly distributed on 21 chromosomes. Most of TaFBKs were predicted to localize in the nucleus and cytoplasm. In silico analysis of a digital PCR revealed that TaFBKs were expressed at multiple developmental stages and tissues, and in response to drought and/or heat stresses. The TaFBK19 gene, a homologous to the Attenuated Far-Red Response ( AFR ) genes in other plant species, and hence named TaAFR , was selected for further analysis. The gene was isolated from the wheat line TcLr15 and its expression evaluated by quantitative real-time PCR. TaAFR transcripts were primarily detected in wheat leaves, and its expression was found to be regulated by various abiotic and biotic stresses as well as plant signaling hormones. Of particular interest, TaAFR expression was differentially regulated in the compatible vs incompatible wheat leaf rust reaction. Subcellular localization studies showed that TaAFR accumulates in the nucleus and cytoplasm. Three TaAFR-interacting proteins were identified experimentally: Skp1/ASK1-like protein (Skp1), ADP-ribosylation factor 2-like isoform X1 (ARL2) and phenylalanine ammonia-lyase (PAL). Further analysis revealed that the Skp1 protein interacted specifically with the F-box domain of TaAFR, while ARL2 and PAL were recognized by the Kelch domain. The data presented herein provides a solid foundation from which the function and metabolic network of TaAFR and other wheat FBKs can be further explored.

scholarly journals Arabidopsis OSMOTIN 34 Functions in the ABA Signaling Pathway and Is Regulated by Proteolysis

2021 ◽  
Vol 22 (15) ◽  
pp. 7915
Author(s):  
Tae-Houn Kim ◽  
Eun-Joo Park
Keyword(s):  
Abiotic Stress ◽  
Signaling Pathway ◽  
Stress Responses ◽  
Translational Control ◽  
26S Proteasome ◽  
Aba Signaling ◽  
Abiotic Stress Response ◽  
Inducible Protein ◽  
F Box Protein

Plants have evolutionarily established resistance responses to a variety of abiotic stress conditions, in which ABA mediates the integrated regulation of these stress responses. Numerous proteins function at the transcription level or at the protein level when contributing to controls of the ABA signaling process. Although osmotin is identified as a salt-inducible protein, its function in the abiotic stress response is yet to be elucidated. To examine the role of Arabidopsis OSMOTIN 34 (OSM34) in the ABA signaling pathway, a deletion mutant osm34 generated by a CRISPR/Cas9 system and the double mutant osm34 osml (osmotin 34-like) were analyzed for various ABA responses. Both osm34 and osm34 osml showed reduced levels of ABA responses in seeds and leaves. Moreover, proline level and expression of the proline biosynthesis gene P5CS1 was significantly reduced in osm34 osml. Interestingly, OSM34 binds to SKP2A, an F-Box protein whose transcription is induced by ABA. The protein stability of OSM34 was determined to be under the control of the 26S proteasome. In conclusion, our data suggest that OSM34 functions as a positive regulator in the generation of ABA responses and is under post-translational control.

scholarly journals Role for Human SIRT2 NAD-Dependent Deacetylase Activity in Control of Mitotic Exit in the Cell Cycle

2003 ◽  
Vol 23 (9) ◽  
pp. 3173-3185 ◽  
Author(s):  
Sylvia C. Dryden ◽  
Fatimah A. Nahhas ◽  
James E. Nowak ◽  
Anton-Scott Goustin ◽  
Michael A. Tainsky
Keyword(s):  
Cell Cycle ◽  
Protein A ◽  
Proteasome Inhibitors ◽  
26S Proteasome ◽  
Functional Studies ◽  
Cellular Life ◽  
Subsequent Decrease ◽  
Subsequent Degradation ◽  
Phosphorylation Cascade ◽  
And Control

ABSTRACT Studies of yeast have shown that the SIR2 gene family is involved in chromatin structure, transcriptional silencing, DNA repair, and control of cellular life span. Our functional studies of human SIRT2, a homolog of the product of the yeast SIR2 gene, indicate that it plays a role in mitosis. The SIRT2 protein is a NAD-dependent deacetylase (NDAC), the abundance of which increases dramatically during mitosis and is multiply phosphorylated at the G2/M transition of the cell cycle. Cells stably overexpressing the wild-type SIRT2 but not missense mutants lacking NDAC activity show a marked prolongation of the mitotic phase of the cell cycle. Overexpression of the protein phosphatase CDC14B, but not its close homolog CDC14A, results in dephosphorylation of SIRT2 with a subsequent decrease in the abundance of SIRT2 protein. A CDC14B mutant defective in catalyzing dephosphorylation fails to change the phosphorylation status or abundance of SIRT2 protein. Addition of 26S proteasome inhibitors to human cells increases the abundance of SIRT2 protein, indicating that SIRT2 is targeted for degradation by the 26S proteasome. Our data suggest that human SIRT2 is part of a phosphorylation cascade in which SIRT2 is phosphorylated late in G2, during M, and into the period of cytokinesis. CDC14B may provoke exit from mitosis coincident with the loss of SIRT2 via ubiquitination and subsequent degradation by the 26S proteasome.

scholarly journals Saccharomyces cerevisiae ubiquitin-like protein Rub1 conjugates to cullin proteins Rtt101 and Cul3 in vivo

2004 ◽  
Vol 377 (2) ◽  
pp. 459-467 ◽  
Author(s):  
Jose M. LAPLAZA ◽  
Magnolia BOSTICK ◽  
Derek T. SCHOLES ◽  
M. Joan CURCIO ◽  
Judy CALLIS
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein A ◽  
Fold Increase ◽  
Lysine Residue ◽  
Reading Frame ◽  
E3 Ligases ◽  
C Terminus ◽  
Dependent Modification ◽  
F Box Protein

In Saccharomyces cerevisiae, the ubiquitin-like protein Rub1p (related to ubiquitin 1 protein) covalently attaches to the cullin protein Cdc53p (cell division cycle 53 protein), a subunit of a class of ubiquitin E3 ligases named SCF (Skp1–Cdc53–F-box protein) complex. We identified Rtt101p (regulator of Ty transposition 101 protein, where Ty stands for transposon of yeast), initially found during a screen for proteins to confer retrotransposition suppression, and Cul3p (cullin 3 protein), a protein encoded by the previously uncharacterized open reading frame YGR003w, as two new in vivo targets for Rub1p conjugation. These proteins show significant identity with Cdc53p and, therefore, are cullin proteins. Modification of Cul3p is eliminated by deletion of the Rub1p pathway through disruption of either RUB1 or its activating enzyme ENR2/ULA1. The same disruptions in the Rub pathway decreased the percentage of total Rtt101p that is modified from approx. 60 to 30%. This suggests that Rtt101p has an additional RUB1- and ENR2-independent modification. All modified forms of Rtt101p and Cul3p were lost when a single lysine residue in a conserved region near the C-terminus was replaced by an arginine residue. These results suggest that this lysine residue is the site of Rub1p-dependent and -independent modifications in Rtt101p and of Rub1p-dependent modification in Cul3p. An rtt101Δ strain was hypersensitive to thiabendazole, isopropyl (N-3-chlorophenyl) carbamate and methyl methanesulphonate, but rub1Δ strains were not. Whereas rtt101Δ strains exhibited a 14-fold increase in Ty1 transposition, isogenic rub1Δ strains did not show statistically significant increases. Rtt101K791Rp, which cannot be modified, complemented for Rtt101p function in a transposition assay. Altogether, these results suggest that neither the RUB1-dependent nor the RUB1-independent form of Rtt101p is required for Rtt101p function. The identification of additional Rub1p targets in S. cerevisiae suggests an expanded role for Rub in this organism.

scholarly journals Nonstructural 3 Protein of Hepatitis C Virus Modulates the Tribbles Homolog 3/Akt Signaling Pathway for Persistent Viral Infection

2016 ◽  
Vol 90 (16) ◽  
pp. 7231-7247 ◽  
Author(s):  
Si C. Tran ◽  
Tu M. Pham ◽  
Lam N. Nguyen ◽  
Eun-Mee Park ◽  
Yun-Sook Lim ◽  
...  
Keyword(s):  
Hepatitis C ◽  
Viral Infection ◽  
Er Stress ◽  
Signaling Pathway ◽  
Akt Signaling ◽  
Hcv Rna ◽  
Akt Signaling Pathway ◽  
Protein Levels ◽  
Persistent Viral Infection ◽  
Infected Cells

ABSTRACTHepatitis C virus (HCV) infection often causes chronic hepatitis, liver cirrhosis, and ultimately hepatocellular carcinoma. However, the mechanisms underlying HCV-induced liver pathogenesis are still not fully understood. By transcriptome sequencing (RNA-Seq) analysis, we recently identified host genes that were significantly differentially expressed in cell culture-grown HCV (HCVcc)-infected cells. Of these, tribbles homolog 3 (TRIB3) was selected for further characterization. TRIB3 was initially identified as a binding partner of protein kinase B (also known as Akt). TRIB3 blocks the phosphorylation of Akt and induces apoptosis under endoplasmic reticulum (ER) stress conditions. HCV has been shown to enhance Akt phosphorylation for its own propagation. In the present study, we demonstrated that both mRNA and protein levels of TRIB3 were increased in the context of HCV replication. We further showed that promoter activity of TRIB3 was increased by HCV-induced ER stress. Silencing of TRIB3 resulted in increased RNA and protein levels of HCV, whereas overexpression of TRIB3 decreased HCV replication. By employing an HCV pseudoparticle entry assay, we further showed that TRIB3 was a negative host factor involved in HCV entry. Bothin vitrobinding and immunoprecipitation assays demonstrated that HCV NS3 specifically interacted with TRIB3. Consequently, the association of TRIB3 and Akt was disrupted by HCV NS3, and thus, TRIB3-Akt signaling was impaired in HCV-infected cells. Moreover, HCV modulated TRIB3 to promote extracellular signal-regulated kinase (ERK) phosphorylation, activator protein 1 (AP-1) activity, and cell migration. Collectively, these data indicate that HCV exploits the TRIB3-Akt signaling pathway to promote persistent viral infection and may contribute to HCV-mediated pathogenesis.IMPORTANCETRIB3 is a pseudokinase protein that acts as an adaptor in signaling pathways for important cellular processes. So far, the functional involvement of TRIB3 in virus-infected cells has not yet been demonstrated. We showed that both mRNA and protein expression levels of TRIB3 were increased in the context of HCV RNA replication. Gene silencing of TRIB3 increased HCV RNA and protein levels, and thus, overexpression of TRIB3 decreased HCV replication. TRIB3 is known to promote apoptosis by negatively regulating the Akt signaling pathway under ER stress conditions. Most importantly, we demonstrated that the TRIB3-Akt signaling pathway was disrupted by NS3 in HCV-infected cells. These data provide evidence that HCV modulates the TRIB3-Akt signaling pathway to establish persistent viral infection.

scholarly journals Role of the PI3-kinase signaling pathway in trafficking of the surfactant protein A receptor P63 (CKAP4) on type II pneumocytes

2010 ◽  
Vol 299 (6) ◽  
pp. L794-L807 ◽  
Author(s):  
Altaf S. Kazi ◽  
Jian-Qin Tao ◽  
Sheldon I. Feinstein ◽  
Li Zhang ◽  
Aron B. Fisher ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Protein A ◽  
Surfactant Protein ◽  
Pi3 Kinase ◽  
Surfactant Protein A ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type Ii Pneumocytes ◽  
Kinase Signaling Pathway ◽  
Stimulation Of

Surfactant protein A (SP-A) plays an important role in the maintenance of lung lipid homeostasis. Previously, an SP-A receptor, P63 (CKAP4), on type II pneumocyte plasma membranes (PM) was identified by chemical cross-linking techniques. An antibody to P63 blocked the specific binding of SP-A to pneumocytes and the ability of SP-A to regulate surfactant secretion. The current report shows that another biological activity of SP-A, the stimulation of surfactant uptake by pneumocytes, is inhibited by P63 antibody. cAMP exposure resulted in enrichment of P63 on the cell surface as shown by stimulation of SP-A binding, enhanced association of labeled P63 antibody with type II cells, and promotion of SP-A-mediated liposome uptake, all of which were inhibited by competing P63 antibody. Incubation of A549 and type II cells with SP-A also increased P63 localization on the PM. The phosphatidylinositol 3-kinase (PI3-kinase) signaling pathway was explored as a mechanism for the transport of this endoplasmic reticulum (ER)-resident protein to the PM. Treatment with LY-294002, an inhibitor of the PI3-kinase pathway, prevented the SP-A-induced PM enrichment of P63. Exposure of pneumocytes to SP-A or cAMP activated Akt (PKB). Blocking either PI3-kinase or Akt altered SP-A-mediated lipid turnover. The data demonstrate an important role for the PI3-kinase-Akt pathway in intracellular transport of P63. The results add to the growing body of evidence that P63 is critical for SP-A receptor-mediated interactions with type II pneumocytes and the resultant regulation of surfactant turnover.

scholarly journals Chemical Activation of the Ethylene Signaling Pathway Promotes Fusarium graminearum Resistance in Detached Wheat Heads

2019 ◽  
Vol 109 (5) ◽  
pp. 796-803 ◽  
Author(s):  
Nora A. Foroud ◽  
Reyhaneh Pordel ◽  
Ravinder K. Goyal ◽  
Daria Ryabova ◽  
Anas Eranthodi ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Fusarium Graminearum ◽  
Host Response ◽  
Chemical Activation ◽  
Disease Spread ◽  
Plant Signaling ◽  
Head Blight ◽  
Wheat Genotypes ◽  
Ethylene Signaling Pathway

Plant signaling hormones such as ethylene have been shown to affect the host response to various pathogens. Often, the resistance responses to necrotrophic fungi are mediated through synergistic interactions of ethylene (ET) with the jasmonate signaling pathway. On the other hand, ET is also an inducer of senescence and cell death, which could be beneficial for some invading necrotrophic pathogens. Fusarium graminearum, a causative agent in Fusarium head blight of wheat, is a hemibiotrophic pathogen, meaning it has both biotrophic and necrotrophic phases during the course of infection. However, the role of ET signaling in the host response to Fusarium spp. is unclear; some studies indicate that ET mediates resistance, while others have shown that it is associated with susceptibility. These discrepancies could be related to various aspects of different experimental designs, and suggest that the role of ET signaling in the host response to FHB is potentially dependent on interactions with some undetermined factors. To investigate whether wheat genotype can influence the ET-mediated response to FHB, the effect of chemical treatments affecting the ET pathway was studied in six wheat genotypes in detached-head assays. ET-inhibitor treatments broke down resistance to both initial infection and disease spread in three resistant wheat genotypes, whereas ET-enhancer treatments resulted in reduced susceptibility in three susceptible genotypes. The results presented here show that the ET signaling can mediate FHB resistance to F. graminearum in different wheat backgrounds.

scholarly journals The Ambivalent Function of YAP in Apoptosis and Cancer

2018 ◽  
Vol 19 (12) ◽  
pp. 3770 ◽  
Author(s):  
Xianbin Zhang ◽  
Ahmed Abdelrahman ◽  
Brigitte Vollmar ◽  
Dietmar Zechner
Keyword(s):  
Clinical Trials ◽  
Signaling Pathway ◽  
Clinical Relevance ◽  
Protein A ◽  
Vital Role ◽  
Cancer Drugs ◽  
Good Target ◽  
Anti Cancer ◽  
The Future

Yes-associated protein, a core regulator of the Hippo-YAP signaling pathway, plays a vital role in inhibiting apoptosis. Thus, several studies and reviews suggest that yes-associated protein is a good target for treating cancer. Unfortunately, more and more evidence demonstrates that this protein is also an essential contributor of p73-mediated apoptosis. This questions the concept that yes-associated protein is always a good target for developing novel anti-cancer drugs. Thus, the aim of this review was to evaluate the clinical relevance of yes-associated protein for cancer pathophysiology. This review also summarized the molecules, processes and drugs, which regulate Hippo-YAP signaling and discusses their effect on apoptosis. In addition, issues are defined, which should be addressed in the future in order to provide a solid basis for targeting the Hippo-YAP signaling pathway in clinical trials.

Brassinosteroids Application Responses in Fruit Crops – A Review

2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Shashi K. Sharma
Keyword(s):  
Plant Hormones ◽  
Agricultural Development ◽  
Enzymatic Reaction ◽  
Plant Responses ◽  
Gene Expressions ◽  
Biotic Stresses ◽  
Horticultural Crops ◽  
Fruit Cracking ◽  
Fruit Plants ◽  
Growing Conditions

Brassinsteroids (BRs) are a class of novel plant hormones gaining importance as potential allies of agricultural development worldwide. Research findings on influences of exogenous BRs application on various aspects of growth and development like vegetative growth, flowering, fruit set, fruit growth, ripening, storage, and tolerance to various biotic and abiotic stresses in fruit plants’ have been reviewed and discussed. The molecular or biochemical aspects of BRs responses to modulate growth and productivity by activating or withholding enzymatic reaction of different biochemical pathways of fruit plants have been elaborated. BRs are involved in ripening and fruit quality development of climacteric and non-climacteric fruits; as per reports of many researchers, they improve fruit color, phenolics, anti-oxidant activities and post-harvest life of many fruits. Fruit cracking in litchi has been found to be significantly reduced due to BRs application. This group of plant hormones possess the capacity to negate genetoxicity and pesticidal residues in many horticultural crops; it reflects the extension of their uses in producing consumer-friendly fruits through BRs application. One of the biggest advantages of BRs application is controlling favorable plant responses under abiotic and biotic stresses; plants have been reported to manage these stresses through modifications in various gene expressions and physiological processes under the influence of the BRs. The need for in-depth studies has been speculated for optimizing the concentration of BRs application together with the standardization of critical stages for harnessing the benefit of quality orchard productivity under varied growing conditions.

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