FIG. 4.
Deconjugation of SUMO1 from A/Duck/Hubei/L-1/2004 (H5N1) NS1 is regulated by SENP1. (A) HEK293T cells were transfected with expression plasmids for NS1CPSFm, Cer-SUMO1, SENP1, or SENP1mut, as indicated, and total DNA levels were adjusted by adding vector plasmid. NS1 was immunoprecipitated (IP) with anti-HA agarose, and precipitated proteins were further analyzed by SDS-PAGE and Western blotting (WB) with anti-HA polyclonal antibody. (B) Modification of H5N1 NS1 protein with endogenous SUMO1. HEK293T cells were cotransfected with NS1CPSFm, SENP1, or SENP1mut, as indicated. Immunoprecipitation and detection of NS1 were performed as described above. Western blots with anti-SUMO1 or anti-actin antibody for whole-cell lysates are shown as input. The positions of molecular mass standards are marked on the left.