Figure 2. Loss-of-function mutation Japan/57 NA_D286G results in colocalization of NA and tetherin in VLPs.

Cos-1 cells were transfected with the loss-of-function Japan/57 NA_D286G mutant, fixed at 48 hours post-transfection and processed for thin section immunogold labeling electron microscopy as described in the Materials and Methods. Panels A-A2, VLPs at the cell surface labeled with 18 nm tetherin gold beads; panels B and C, VLPs at the cell surface double labeled for NA (12nm gold) and tetherin (18nm gold). Circles in panel A2 indicate tetherin gold labeling at apparent fusion points between VLP particles. Large and small arrows in panels B and C indicate 18 nm tetherin gold labeling and 12 nm NA gold labeling within single VLPs, respectively.