FIG. 4.

Specific association of endogenous and ectopically expressed SRPK1 and SRPK2 with GST-HBV core protein. COS-7 cells were transiently transfected with either control vectors or plasmids encoding FLAG-tagged SRPK1 (1.5 μg/well) or VSV-tagged SRPK2 (1.0 μg/well). After 24 h, cells were lysed, and extracts were subjected to in vitro association with either GST or GST-HBV-C1 protein. Samples were then resolved in duplicate by SDS-PAGE, followed by immunoblotting with anti-SRPK1 and anti-FLAG antibodies (left panels) or anti-SRPK2 and anti-VSV antibodies (right panels).