Identification of RNase L-Dependent, 3'-End-Modified, Viral Small RNAs in Sindbis Virus-Infected Mammalian Cells

Girardi, Erika; Chane-Woon-Ming, Béatrice; Messmer, Mélanie; Kaukinen, Pasi; Pfeffer, Sébastien

RNase L is involved in the production of SvsRNAs. We then hypothesized that an endoribonuclease involved in the antiviral response could be implicated in SvsRNA production. RNase L is a ubiquitous, cytoplasmic, interferon-induced endonuclease that plays a key role in the cellular response to viral infections. It cleaves single-stranded RNA regions after the dinucleotides UA/UU, thereby preventing virus accumulation (28) . As such, we knocked down RNase L using siRNAs, before infecting the cells with SINV. As expected, RNase L knockdown (KD) resulted in the upregulation of the SINV genome by approximately 2.5-fold ( Fig. 2A and B) . Interestingly, it also resulted in a dramatic reduction of the viral small RNAs SvsRNA-1, -2, and -3 and their precursors (Fig. 2C) .