Mov34 protein from mouse brain interacts with the 3 ' noncoding region of Japanese encephalitis virus

The plus-sense RNA genome of Japanese encephalitis virus (JEV) contains non coding regions (NCRs) of 95 and 585 bases at its 5' and 3' ends, respective ly. The last 83 nucleotides of the 3'-NCR are predicted to form stable stem -loop (SL) structures. The shape of this 3'-SL structure is highly conserve d among divergent flaviviruses even though only small stretches of nucleoti de sequence contained within these structures are conserved. These SL struc tures have been predicted to function as cis-acting signals for RNA replica tion and as such may bind to viral and cellular proteins that may be involv ed in viral replication. We have studied the interaction of the JEV 3'-NCR RNA with host proteins using gel retardation assays. We show that the JEV 3 '-SL structure RNA forms three complexes with proteins from the S100 cytopl asmic extract prepared from the neonatal mouse brain. These complexes could be obtained in the presence of 200 mM KCl, indicating that the RNA-protein interaction may be physiologically relevant. UV-induced cross-linking and Northwestern blotting analyses deterred three proteins with apparent molecu lar masses of 32, 35, and 50 kDa that bound to the JEV 3'-SL structure RNA. Screening of the neonatal mouse brain cDNA library with the JEV 3'-SL stru cture RNA identified a 36-kDa Mov34 protein interacting with it. Competitio n experiments using the RNA extracted from JEV virions established that the 36-kDa Mov34 protein indeed bound to the JEV genome. Murine Mov34 belongs to a family of proteins whose members have been shown to be involved in RNA transcription and translation. It is, therefore, likely that the murine Mo v34 interaction with JEV 3'-NCR has a role in RNA replication.