Analyses of the Golgi pool of Cav1. (A) P-11 and (B) TCN23-19 cells were transfected with Cav1-YFP. After 24 h, cells were fixed and stained for giantin and imaged. (C) P-11 and (D) TCN23-19 cells were immunostained for endogenous Cav1 and giantin. The white square area was enlarged and showed at the top right corner of the merged image to display the colocalization of giantin with Cav1. (E) P-11 and TCN23-19 cells were extracted by cold 0.1% Triton X-100 for 2 min as described in Materials and methods. Both soluble and insoluble fractions were collected and subjected to Western blot detection of α1 and Cav1. A representative blot of three independent experiments is shown. (F) P-11(a and b) and TCN23-19 (c and d) cells were transfected with Cav1-YFP for 3 h, then cells were fixed and stained for giantin (a and c). In b and d, transfected cells were treated with 10 μg/ml cycloheximide (Chx) for 3 h, then stained for giantin. Similar experiments were repeated at least four times. Images were taken by confocal microscope. Bars stand for 5 μm in all images.