Figure 1.

Surf4 localizes mainly to the ERGIC. (A) Localization of endogenous Surf4 in HeLa cells by confocal immunofluorescence microscopy using affinity-purified antibodies against Surf4 in combination with antibodies against ERGIC-53, giantin, and BAP31. Right, HeLa cells were treated with 10 μg/ml BFA for 90 min (+BFA) and labeled with antibodies against Surf4 and ERGIC-53. (B) HeLa cells were transfected with HA-Surf4 or HA-Surf4SSS. The tagged versions of Surf4 were stained with anti-HA and costained with anti-ERGIC-53 and anti-giantin antibodies. Arrowheads indicate colocalization of HA-Surf4 with ERGIC-53. Bars, 10 μm.