RNPC3 and infection: Upon infection, once the virus RNP is delivered into the cytoplasm of the host cell, the L polymerase associated with the viral RNP initiates transcription from the genome promoter located at the 3’-end of each genomic RNA segment, L and S. The 5’ and 3’ terminal 19 nt viral promoter regions of both RNA segments required for the recognition and binding by the viral polymerase [11] exhibit a high degree of conservation among arenaviruses.