Furin cleavage site alignment and DENV maturation. (A) Amino acid sequence alignment of viral furin cleavage sites from position 9 (P9) to position 1 prime (P1′). PiTou scores are the prediction of logarithmic-odd probabilities of all the different viral furin cleavage sites (higher value = better substrate for furin). Viruses: DENV1, -2, -3, and -4; Zika virus (ZIKV); West Nile virus (WNV); Japanese encephalitis virus (JEV); yellow fever virus (YFV); Tick-borne encephalitis virus (TBEV); Kyasanur Forest disease virus (KFDV); Kunjin virus (KUN); Murray Valley encephalitis virus (MVEV); St. Louis encephalitis virus (SLEV); Powassan virus (POW); Usutu virus (USUV); highly pathogenic avian influenza virus (HPAI); SARS-Coronavirus-2. (B) Representative Western blot image of DV1-WT, DV2-WT, DV3-WT, and DV4-WT viral supernatants grown in either Vero or C6/36 blotted with anti-Env and anti-prM antibodies.