Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The nonexpressor of pathogenesis-related (PR) genes (NPR1) protein plays an important role in mediating defense responses activated by pathogens in Arabidopsis. In rice, a disease-resistance pathway similar to the Arabidopsis NPR1-mediated signaling pathway one has been described. Here, we show that constitutive expression of the Arabidopsis NPR1 (AtNPR1) gene in rice confers resistance against fungal and bacterial pathogens. AtNPR1 exerts its protective effects against fungal pathogens by priming the expression of salicylic acid (SA)-responsive endogenous genes, such as the PR1b, TLP (PR5), PR10, and PBZ1. However, expression of AtNPR1 in rice has negative effects on viral infections. The AtNPR1-expressing rice plants showed a higher susceptibility to infection by the Rice yellow mottle virus (RYMV) which correlated well with a misregulation of RYMV-responsive genes, including expression of the SA-regulated RNA-dependent RNA polymerase 1 gene (OsRDR1). Moreover, AtNPR1 negatively regulates the expression of genes playing a role in the plant response to salt and drought stress (rab21, salT, and dip1), which results in a higher sensitivity of AtNPR1 rice to the two types of abiotic stress. These observations suggest that AtNPR1 has both positive and negative regulatory roles in mediating defense responses against biotic and abiotic stresses.
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PMID:The Arabidopsis AtNPR1 inversely modulates defense responses against fungal, bacterial, or viral pathogens while conferring hypersensitivity to abiotic stresses in transgenic rice. 1870 Aug 26

In mouse ovarian follicles, the oocyte is maintained in meiotic prophase arrest by natriuretic peptide type C (NPPC) acting via its cognate receptor, natriuretic peptide receptor 2 (NPR2). As there is a marked species difference in the receptor selectivity of the natriuretic peptide family, this study examined the functional effect of other natriuretic peptides, type A (NPPA) and type B (NPPB), acting via NPR2 on mouse-oocyte meiotic arrest. The results by quantitative, reverse-transcriptase PCR showed that Npr2 was the predominant natriuretic peptide receptor transcript, and that Npr1 and Npr3 mRNA levels were negligible in cumulus cells isolated from equine chorionic gonadotropin (eCG)-primed, immature female mice. While NPPA and NPPB from human and rat had no effect on oocyte maturation, porcine NPPB (pNPPB) maintained oocyte meiotic arrest in a dose-dependent manner. Furthermore, pNPPB-mediated meiotic arrest and cGMP production could be completely blocked by the NPR2 inhibitor sphingosine-1-phosphate (S1P). Neither the NPR1 antagonist anantin or Npr1 knockout had an effect on pNPPB-mediated meiotic arrest. Thus, pNPPB can functionally maintain mouse-oocyte meiotic arrest by the receptor NPR2 of cumulus cells. These findings demonstrate that pNPPB may be used as a probe to identify the essential amino acid sequences for activation of NPR2.
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PMID:Porcine natriuretic peptide type B (pNPPB) maintains mouse oocyte meiotic arrest via natriuretic peptide receptor 2 (NPR2) in cumulus cells. 2461 55

A defence response can be induced by nonpathogenic Fusarium oxysporum CS-20 in several crops, but the molecular mechanism has not been clearly demonstrated. In the present study, we analysed the defence mechanism of a susceptible cucumber cultivar (Cucumis sativus L. 9930) against a pathogen (F. oxysporum f. sp. cucumerinum) through the root precolonization of CS-20. A challenge inoculation assay indicated that the disease severity index (DSI) was reduced, ranging from 18.83 to 61.67 in comparison with the pathogen control. Root colonization analysis indicated that CS-20 clearly did not appear to influence the growth of cucumber seedlings. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) revealed that CS-20-mediated defence response was activated by PR3, LOX1 and PAL1 and the pathogen-mediated resistance response was regulated by PR1 and PR3. Moreover, both nonpathogenic and pathogenic F. oxysporum were able to upregulate NPR1 expression. In contrast to a pathogen, CS-20 can activate the Ca(2+) /CaM signal transduction pathway, and the gene expression of both CsCam7 and CsCam12 increased significantly. The gene expression analysis indicated that CS-20 strongly enhanced the expression of PR3, LOX1, PAL1, NPR1, CsCam7 and CsCam12 after inoculation. Overall, the defence response induced by CS-20 can be controlled by multiple genes in the cucumber plant.
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PMID:Analysis of the defence-related mechanism in cucumber seedlings in relation to root colonization by nonpathogenic Fusarium oxysporum CS-20. 2481 Mar 67

Sumoylation is a transient, reversible dynamic posttranslational modification that regulates diverse cellular processes including plant-pathogen interactions. Sumoylation of NPR1, a master regulator of basal and systemic acquired resistance to a broad spectrum of plant pathogens, activates the defense response. Here, we report that NIb, the only RNA-dependent RNA polymerase of Turnip mosaic virus (TuMV) that targets the nucleus upon translation, interacts exclusively with and is sumoylated by SUMO3 (SMALL UBIQUITIN-LIKE MODIFIER3), but not the three other Arabidopsis thaliana SUMO paralogs. TuMV infection upregulates SUMO3 expression, and the sumoylation of NIb by SUMO3 regulates the nuclear-cytoplasmic partitioning of NIb. We identified the SUMO-interacting motif in NIb that is essential for its sumoylation and found that knockout or overexpression of SUMO3 suppresses TuMV replication and attenuates viral symptoms, suggesting that SUMO3 plays dual roles as a host factor of TuMV and as an antiviral defender. Sumoylation of NIb by SUMO3 is crucial for its role in suppressing the host immune response. Taken together, our findings reveal that sumoylation of NIb promotes TuMV infection by retargeting NIb from the nucleus to the cytoplasm where viral replication takes place and by suppressing host antiviral responses through counteracting the TuMV infection-induced, SUMO3-activated, NPR1-mediated resistance pathway.
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PMID:Sumoylation of Turnip mosaic virus RNA Polymerase Promotes Viral Infection by Counteracting the Host NPR1-Mediated Immune Response. 2822 39

Potyviruses represent the largest group of known plant RNA viruses and include many agriculturally important viruses, such as Plum pox virus, Soybean mosaic virus, Turnip mosaic virus, and Potato virus Y. Potyviruses adopt polyprotein processing as their genome expression strategy. Among the 11 known viral proteins, the nuclear inclusion protein b (NIb) is the RNA-dependent RNA polymerase responsible for viral genome replication. Beyond its principal role as an RNA replicase, NIb has been shown to play key roles in diverse virus-host interactions. NIb recruits several host proteins into the viral replication complexes (VRCs), which are essential for the formation of functional VRCs for virus multiplication, and interacts with the sumoylation pathway proteins to suppress NPR1-mediated immunity response. On the other hand, NIb serves as a target of selective autophagy as well as an elicitor of effector-triggered immunity, resulting in attenuated virus infection. These contrasting roles of NIb provide an excellent example of the complex co-evolutionary arms race between plant hosts and potyviruses. This review highlights the current knowledge about the multifunctional roles of NIb in potyvirus infection, and discusses future research directions.
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PMID:The RNA-Dependent RNA Polymerase NIb of Potyviruses Plays Multifunctional, Contrasting Roles during Viral Infection. 3193 67