A49 interacts with the ubiquitin E3 ligase β-TrCP.

<p>(A) Alignment of β-TrCP recognition motif present in A49, IκBα, IκBβ, β-catenin, Emi1, HIV Vpu and p105. Phosphorylated serine residues are shown in bold and numbers indicate the first residue of the motif in each protein. (B) HeLa cells were cotransfected with myc-β-TrCP or myc-TAK1, with nTAP-A49 or nTAP-C6. Cells were lysed with IP buffer 24 h later and proteins pulled down with streptavidin beads. Whole cell lysate (WCL) (3%) of each sample was analysed. (C) HeLa cells were transfected with TAP-RIG-I or TAP-β-TrCP, and 24 h later were mock-infected or infected with vΔA49 or vA49rev at 10 PFU/cell for 6 h. Cells were lysed in IP buffer and a streptavidin pull-down was performed. D8 immunoblotting served as control for viral infection. WCL (1.5%) of each sample was analysed. (D) HeLa cells were either mock-infected or infected with vΔA49 or vA49rev with 10 PFU/cell for 6 h. After lysis with IP buffer, lysates were immunoprecipitated with a goat anti-β-TrCP antibody or an isotype control. WCL (1%) of each sample was analysed. Asterisk marks the antibody heavy chain. Data shown in (B) and (C) are one representative experiment of at least three. Data shown in (D) are one representative experiment out of two showing indistinguishable results.