FIG. 5.

Influenza virus NP and polymerase complex interact with hStau1 complexes. To determine which viral RNP proteins interact with hStau1, HEK293T cells were cotransfected with the plasmid expressing hStau1-TAP (or the TAP tag as a control) and all plasmids required to generate an active RNP (pCMV-PB1, pCMV-PB2, pCMV-PA, pCMV-NP and pHH-NS1) (A), each of the plasmids individually expressing the protein components of the RNP (B), the plasmids expressing the viral polymerase (C), or a plasmid expressing NP (D) (the cell lysis was performed in the presence or absence of RNase A). In every set of experiments, after 24 h posttransfection, cell extracts were used to carry out TAP purification. Aliquots of the total extract (Input), material not bound to IgG-Sepharose resin (NBIgG), and material eluted from the IgG-Sepharose resin (eluted) were analyzed by Western blotting with antibodies specific for PA, PB1, PB2, NP, NS1, and hStau1, as indicated to the right. The asterisk in panel A indicates a cross-reaction of the anti-hStau1 antibody.