Figure 1.
Structure and expression pattern of gephyrin constructs in COS-7 cells.
A
, G, C (or L), and E correspond to the N-terminal, central (or linker), and C-terminal domains of gephyrin, respectively. Ge(2) is the most abundant splice variant of gephyrin. Insertion of cassettes 4 and 5 (light gray boxes) generates the ge(2,4,5) variant. The constructs are N-terminally tagged either with Venus or mrfp.
B
, COS-7 cells cotransfected with vege(2), mrfpge(2), and the myc-tagged GlyR subunit GlyRα1βgb form gephyrin clusters (both in the green and the red channels) that colocalize with surface GlyRα1βgb immunostained 24 h after transfection.
C
, Over-expression of the truncated construct mrfpG(2) results in a diffuse distribution and a reduction in the size of gephyrin/GlyRα1βgb coclusters (arrows in the magnified images). Scale bar, 10 μm.
D
,
E
, Quantification of the size (
D
) and relative cellular surface area covered by vege(2)/GlyRα1βgb clusters (
E
) in COS-7 cells cotransfected with the different mrfp-tagged gephyrin constructs [means ± SEM; N = at least 10 cells for each condition; Student's t test, significant differences from mrfpge(2) with p ≤ 10−3 (***), 10−2 (**), and 5 × 10−2 (*)].