Messenger RNA Cap Methylation in Vesicular Stomatitis Virus, a Prototype of Non‐Segmented Negative‐Sense RNA Virus

The non‐segmented negative‐sense (NNS) RNA viruses encompass a wide range of signifi‐ cant human, animal, and plant pathogens including several National Institute of Allergy and Infectious Diseases (NIAID) Category A and C biodefense pathogens. The NNS RNA viruses are classified into four families: the Rhabdoviridae, as exemplified by rabies virus and vesicular stomatitis virus (VSV); the Paramyxoviridae, as exemplified by human respiratory syncytial virus (RSV), human metapneumovirus (hMPV), human parainfluenza virus type 3 (PIV3), measles virus, mump virus, Newcastle disease virus (NDV), Nipah virus, and Hen‐ dra virus; the Filoviridae, as exemplified by Ebola and Marburg viruses; and the Bornaviridae, as exemplified by Borna disease virus. For many of these viruses, there are no effective vac‐ cines or anti-viral drugs. RSV, hMPV, and PIV3 account for more than 70% of acute viral respiratory diseases, especially in infants, children, and the elderly [1, 2]. hPIV 1-3 have been recognized as the causative agents of croup since the late 1950’s [3]. In addition, measles re‐ mains a major killer of children worldwide, despite successful vaccination programs in de‐ veloped countries [4]. The most virulent strains of NDV, the viscerotropic velogenic strains (often called “exotic” NDV), are classified as High Consequence Livestock Pathogens by US‐ DA due to their potential as agents of agricultural bioterrorism [5].