Fig. 1
SCAMP2 regulates T-type channel expression. a Co-immunoprecipitation of Myc-tagged SCAMP2 (SCAMP2-Myc) from tsA-201 cells co-transfected with HA-tagged Cav3.2 channel (Cav3.2-HA). The upper panel shows the result of the co-immunoprecipitation of SCAMP2-Myc with Cav3.2-HA using an anti-HA antibody. The lower panels show the immunoblot of Cav3.2-HA and SCAMP2-Myc from total cell lysates using an anti-HA and anti-Myc antibody, respectively. HC, heavy chain antibody; LC, light chain antibody. This experiment was performed four times from independent transfections and Cav3.2/SCAMP2 interaction was consistently observed. b Representative T-type current traces from tsA-201 cells expressing Cav3.2 alone (black traces) and in combination with wild-type SCAMP2 (blue traces), as well as with C201A (purple traces) and W202A (orange traces) SCAMP2 mutants in response to 150 ms depolarizing steps varied from − 90 mV to + 30 mV from a holding potential of − 100 mV. c Corresponding mean current/voltage (I/V) relationships. d Corresponding mean maximal macroscopic conductance values (Gmax) obtained from the fit of the I/V curves with the modified Boltzmann Eq. (1). e–f Mean Gmax values for tsA-201 cells expressing Cav3.1 and Cav3.3 channels, respectively. g. Immunoblot of Cav3.2-HA expressed in tsA-201 cells in the absence (−) and presence (+) of SCAMP2-Myc. The immunoblot shows the results of three independent sets of transfections. h Corresponding mean expression levels of Cav3.2-HA normalized to actin. i Representative intramembrane charge movement traces recorded at the ionic reversal potential from cells expressing Cav3.2 alone (black trace) and in the presence of SCAMP2 (blue trace). The doted lines depict the time course of the intramembrane charge mouvement integral. j Corresponding mean maximal intramembrane charge movement values (Qmax). k Corresponding mean 10–90% rise time values calculated from the integral time course shown in i. l Corresponding mean Gmax/Qmax values