Fig. 4. Detection of cell surface FcRn. The cell surface of FO-1 cells (lane 3),
FO-1ß2m cells (lane 5), FO-1 cells expressing Myc-hFcRn (lanes 1,4) and
FO-1ß2m cells expressing Myc-hFcRn (lanes 2,6) were biotinylated on ice
with a membrane-impermeable reagent. Cells were lysed and an aliquot of the
lysates directly analyzed by immunoblotting (lysate; lanes 1,2) to detect the
presence of Myc-hFcRn (
-Myc). The remaining lysate was precipitated
with anti-Myc antibodies (-Myc IP) and biotinylated Myc-hFcRn present
in the precipitates detected by blotting with streptavidin-HRP (SA-HRP, lanes
3-6, top panel). Alternatively, biotinylated proteins were first precipitated
with streptavidin-agarose (SA-P) and precipitates immunoblotted to detect
Myc-hFcRn (-Myc, lower panel). hc, heavy chain of the antibody used for
immunoprecipitation. The data shown is representative of at least three
independent experiments, each carried out using two different cell clones.
