In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

doi: bioRxiv preprint 65 required for the antiviral activity of both IFITM3 and IFITM1 [9]. The subcellular localization of 66 IFITMs is a key determinant of their antiviral profile. When expressed singly, IFITM3 and IFITM2 67 preferentially localize to early and late endosomes and lysosomes, and restrict viruses that enter via 68 these endo-lysosomal compartments. In contrast, IFITM1 primarily localizes at the cell surface and 69 can restrict viruses that enter through the plasma membrane [11-14]. Indeed, mutants of IFITM3 70 that lack an N-terminal endocytic sorting motif 20 YEML 23 localize to the plasma membrane and lose 71 their ability to inhibit influenza A virus (IAV), alphavirus and coronavirus infection by endosomal 72 routes [14-18]. 73 74 Studies focusing on IFITM3 restriction of IAV and Semliki Forest Virus (SFV) indicate that virus 75 internalization is unaffected by IFITM3 expression and, for SFV at least, the viral envelope 76 . CC-BY-NC-ND 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/737841 doi: bioRxiv preprint 109 knockout mice show enhanced morbidity after infection with IAV, alphaviruses and flaviviruses [33-110 .
Comparative analysis reveals adaptive evolution of bat IFITMs and a novel 1 antiviral determinant

Ebola virus (EboV) belongs to the Filoviridae family of viruses that causes severe and fatal hemhorragic fever. Infection by EboV involves fusion between the virus and host cell membranes mediated by the envelope glycoprotein GP2 of the virus. Similar to the envelope glycoproteins of other viruses, the central feature of the GP2 ectodomain postfusion structure is a six-helix bundle formed by the protein's N-and C-heptad repeat regions (NHR and CHR, respectively). Folding of this six-helix bundle provides the energetic driving force for membrane fusion; in other viruses, designed agents that disrupt formation of the six-helix bundle act as potent fusion inhibitors. To interrogate determinants of EboV GP2-mediated membrane fusion, we designed model proteins that consist of the NHR and CHR segments linked by short protein linkers. Circular dichroism and gel filtration studies indicate that these proteins adopt stable ahelical folds consistent with design. Thermal denaturation indicated that the GP2 six-helix bundle is highly stable at pH 5.3 (melting temperature, T m , of 86.8 6 2.0°C and van't Hoff enthalpy, DH vH , of 228.2 6 1.0 kcal/mol) and comparable in stability to other viral membrane fusion six-helix bundles. We found that the stability of our designed a-helical bundle proteins was dependent on buffering conditions with increasing stability at lower pH. Small pH differences (5.3-6.1) had dramatic effects (DT m 5 37°C) suggesting a mechanism for conformational control that is dependent on environmental pH. These results suggest a role for low pH in stabilizing six-helix bundle formation during the process of GP2-mediated viral membrane fusion.
Designed protein mimics of the Ebola virus glycoprotein GP2 a-helical bundle: Stability and pH effects

Background: Astroviruses (AstVs) have been reported to infect and cause gastroenteritis in most animal species. Human AstVs were regarded the causative agent of viral diarrhea in children. In dogs, little is known about the epidemiology and clinical significance of AstV infection. Findings: In this study, we collected and tested 253 rectal swabs from pet dogs; of which 64 samples (25.3%) tested positive for AstVs with diarrhea and 15 more samples (5.9%) also was identified as AstVs, however without any clinical signs. Phylogenetic analysis of 39 partial ORF1b sequences from these samples revealed that they are similar to AstVs, which can be subdivided into three lineages. Interestingly, out of the 39 isolates sequenced, 16 isolates are shown to be in the Mamastrovirus 5/canine astrovirus (CAstV) lineage and the remaining 23 isolates displayed higher similarities with known porcine astrovirus (PoAstV) 5 and 2. Further, analysis of 13 capsid sequences from these isolates showed that they are closely clustered with Chinese or Italy CAstV isolates. The findings indicate that CAstVs commonly circulate in pet dogs, and our sequencing results have shown the genomic diversity of CAstVs leading to increasing number of clusters.

Detection and genetic characterization of canine astroviruses in pet dogs in Guangxi, China