Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dengue is the most prevalent arboviral disease worldwide. The outcome of the infection is determined by the interplay of viral and host factors. In the present study, we evaluated the cellular response of human monocyte-derived DCs (mdDCs) infected with recombinant dengue virus type 1 (DV1) strains carrying a single point mutation in the NS3hel protein (L435S or L480S). Both mutated viruses infect and replicate more efficiently and produce more viral progeny in infected mdDCs compared with the parental, non-mutated virus (vBACDV1). Additionally, global gene expression analysis using cDNA microarrays revealed that the mutated DVs induce the up-regulation of the interferon (IFN) signalling and pattern recognition receptor (PRR) canonical pathways in mdDCs. Pronounced production of type I IFN were detected specifically in mdDCs infected with DV1-NS3hel-mutated virus compared with mdDCs infected with the parental virus. In addition, we showed that the type I IFN produced by mdDCs is able to reduce DV1 infection rates, suggesting that cytokine function is effective but not sufficient to mediate viral clearance of DV1-NS3hel-mutated strains. Our results demonstrate that single point mutations in subdomain 2 have important implications for adenosine triphosphatase (ATPase) activity of DV1-NS3hel. Although a direct functional connection between the increased ATPase activity and viral replication still requires further studies, these mutations speed up viral RNA replication and are sufficient to enhance viral replicative capacity in human primary cell infection and circumvent type I IFN activity. This information may have particular relevance for attenuated vaccine protocols designed for DV.
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PMID:Single point mutations in the helicase domain of the NS3 protein enhance dengue virus replicative capacity in human monocyte-derived dendritic cells and circumvent the type I interferon response. 2634 Apr 9

The yellow fever mosquito Aedes aegypti is the major vector of arboviruses, causing numerous devastating human diseases, such as dengue and yellow fevers, Chikungunya and Zika. Female mosquitoes need vertebrate blood for egg development, and repeated cycles of blood feeding are tightly linked to pathogen transmission. The mosquito's posterior midgut (gut) is involved in blood digestion and also serves as an entry point for pathogens. Thus, the mosquito gut is an important tissue to investigate. The miRNA aae-miR-275 (miR-275) has been shown to be required for normal blood digestion in the female mosquito; however, the mechanism of its action has remained unknown. Here, we demonstrate that miR-275 directly targets and positively regulates sarco/endoplasmic reticulum Ca2+ adenosine triphosphatase, which is implicated in active transport of Ca2+ from the cytosol to the sarco/endoplasmic reticulum. We utilized a combination of the gut-specific yeast transcription activator protein Gal4/upstream activating sequence (Gal4/UAS) system and miRNA Tough Decoy technology to deplete the endogenous level of miR-275 in guts of transgenic mosquitoes. This gut-specific reduction of miR-275 post blood meal decreased SERCA mRNA and protein levels of the digestive enzyme late trypsin. It also resulted in a significant reduction of gut microbiota. Moreover, the decrease of miR-275 and SERCA correlated with defects in the Notch signaling pathway and assembly of the gut actin cytoskeleton. The adverse phenotypes caused by miR-275 silencing were rescued by injections of miR-275 mimic. Thus, we have discovered that miR-275 directly targets SERCA, and the maintenance of its level is critical for multiple gut functions in mosquitoes.
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PMID:MicroRNA-275 targets sarco/endoplasmic reticulum Ca2+ adenosine triphosphatase (SERCA) to control key functions in the mosquito gut. 2878 46

The protein-RNA interactions within the flavivirus replication complex (RC) are not fully understood. Our structure of dengue virus NS3 adenosine triphosphatase (ATPase)/helicase bound to the conserved 5' genomic RNA 5'-AGUUGUUAGUCU-3' reveals that D290 and R538 make specific interactions with G2 and G5 bases respectively. We show that single-stranded 12-mer RNA stimulates ATPase activity of NS3, however the presence of G2 and G5 leads to significantly higher activation. D290 is adjacent to the DEXH motif found in SF2 helicases like NS3 and interacts with R387, forming a molecular switch that activates the ATPase site upon RNA binding. Our structure guided mutagenesis revealed that disruption of D290-R387 interaction increases basal ATPase activity presumably as a result of higher conformational flexibility of the ATPase active site. Mutational studies also showed R538 plays a critical role in RNA interactions affecting translocation of viral RNA through dynamic interactions with bases at positions 4 and 5 of the ssRNA. Restriction of backbone flexibility around R538 through mutation of G540 to proline abolishes virus replication, indicating conformational flexibility around residue R538 is necessary for RNA translocation. The functionally critical sequence-specific contacts in NS3 RNA binding groove in subdomain III reveals potentially novel allosteric anti-viral drug targets.
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PMID:NS3 helicase from dengue virus specifically recognizes viral RNA sequence to ensure optimal replication. 2916 89