Effect of PB1c45 on Influenza Virus Replication

Influenza virus RNA polymerase is composed of three subunits, PB1, PB2 and PA, which is involved in both transcription and replication of viral genome RNA, negative strand RNA. Influenza virus gene product RNA dependent RNA polymerase synthesizes two different RNAs, one is mRNA and another is cRNA which become a template for virus genome RNA synthesis. To synthesize two different RNAs the RNA polymerase should be converted by some factor(s) in the virus infected cell. It was speculated that between polymerase structure and function could be some relations. It is started to screen the protein(s) which interact(s) with RNA polymerase using yeast two-hybrid screening system. Nine host proteins were identified, which interacted with different polymerase subunits. One of them, PB1c45, which interacted with PB1 subunit in polymerase and molecular weight was 45kDa, was analyzed the effect on polymerase activity and influenza virus infectivity. The PB1c45 inhibited the polymerase activity and also reduced the influenza virus infectivity