FIGURE 3.
Immunocytochemical staining of Kv1.5 and Kvβ1.3-Myc subunits using antibody-induced patching. A, positive control. Colocalization of the subunits appears as yellow membrane clusters due to the merge of the green (Kv1.5) and red (Kvβ1.3-Myc) channels after detection with secondary fluorescent antibodies. B, negative control. Kv2.1-HA and Kvβ1.3-Myc channels do not assemble. Thus, they were used as a negative control for colocalization. Lack of colocalization is visualized as an absence of yellow fluorescence. C, calphostin C-treated (200 nm) cells transiently transfected with Kv1.5+Kvβ1.3-Myc; yellow fluorescence is evident in patches of the membrane, indicating colocalization of Kv1.5 and Kvβ1.3-Myc subunits in the cell membrane. In all pictures, the bar represents 5 μm. D, histograms of the pixel-by-pixel analysis of the section indicated by lines in Merge panels in A, B, and C, respectively.