Figure 3.

Depletion of cellular B55 by pECE-B55as. (A) Hs68 were transiently transfected with the empty pECE plasmid (mock) or with the B55 antisense construct pECE-B55as (B55as). Thirty-six hours after transfection 50 μg of total lysate were electrophoretically separated and immunoblotted using Ab55^recomb. Immunodecoration using Ab55^473/448 revealed a similar disappearance of B55 in extracts of pECE-B55as-transfected cells. In parallel experiments an efficiency of 60% transfection was determined using a green fluorescent protein expression construct. (B and C) Cells were microinjected with the B55-antisense RNA–expressing construct pECE-B55as, mixed with mouse immunoglobulin G, cultured for a further 15 h, fixed, and stained for B55 using Ab55^473/448 (B). The arrowheads indicate the microinjected cell as identified by costaining for the microinjection marker antibody (C). Note that this cell has been exclusively microinjected in the nucleus. Bar, 5 μm.