Figure 1.

CAML interacts with the γ2 but not α2 and β3 subunits in transfected 293T cells. A-F, Human embryo kidney 293T cells were transfected with α2β3^mycγ2 (A, B) or α2β3 receptors (C - F), either alone (A, C, E) or together with FL-CAML (B, D, F) and stained with antibodies specific for the ^mycγ2 subunit (A2, B2, blue), the α2 subunit (A3, B3, C, D2, red) or β3 subunit (E, F2) and FL-CAML (B1, D1, F1, green). Panel A1 shows a bright field image; the other panels show single optical sections of representative cells imaged by confocal microscopy. Merged images representing two or three separate fluorescent channels of cells in A, B, D, and F are shown in the right column. Note the colocalization of α2 and γ2 subunits at the cell surface of the α2β3^mycγ2 receptor-transfected cell in (A) evident in the merged image (A4) that is absent upon cotransfection of CAML with α2β3^mycγ2 receptors in the cell shown in (B) (merged image B4). Whereas cells cotransfected with FL-CAML and α2β3^mycγ2 show intracellular trapping of the γ2 (B2, B4) and α2 subunits (B3), virtually no intracellular GABA_AR subunit staining is seen when α2β3^mycγ2 receptors are transfected alone (A2-4), or upon cotransfection of α2β3 receptors with FL-CAML (D2, D3, F2, F3). Arrows point to colocalization of FL-CAML and GABA_AR subunits, arrowheads indicate lack of colocalization. Scale bar, 10 μm.