https://www.selleckchem.com/products/bay-3827.html Yellow fever virus, the prototype in the genus Flavivirus, was used to develop viruses in which the nonstructural protein NS1 is genetically fused to GFP in the context of viruses capable of autonomous replication. The GFP-tagging of NS1 at the amino-terminus appeared possible despite the presence of a small and functionally important domain at the NS1's amino-terminus which can be distorted by such fusing. GFP-tagged NS1 viruses were rescued from DNA-launched molecular clones. The initially produced GFP-tagged NS1 virus was capable of only poor replication. Sequential passages of the virus in cell cultures resulted in the appearance of mutations in GFP, NS4A, NS4B and NS5. The mutations which change amino acid sequences of GFP, NS4A and NS5 have the adaptive effect on the replication of GFP-tagged NS1 viruses. The pattern of GFP-fluorescence indicates that the GFP-NS1 fusion protein is produced into the endoplasmic reticulum. The intracellular GFP-NS1 fusion protein colocalizes with dsRNA. The discovered forms of extracellular GFP-NS1 possibly include tetramers and hexamers.The analysis of neutralizing epitope of dengue virus (DENV) is important for the development of an effective dengue vaccine. A potent neutralizing mouse monoclonal antibody named 7F4 was previously reported and, here, we further analyzed the detailed epitope of this antibody. 7F4 recognized a novel conformational epitope close to the N-67 glycan on the envelope protein. This antibody was specific to the DENV that lacks N-67 glycan, including the Mochizuki strain. Interestingly, the Mochizuki strain acquired N-67 glycan by 7F4 selective pressure. Considering that most of the currently circulating DENVs possess N-67 glycan, DENVs may have evolved to escape from antibodies targeting 7F4 epitope, suggesting the potency of this neutralizing epitope. In addition, this study demonstrated the existence of the epitopes close to 7F4 epitope and their cruc