Effects of Sig-1R ligands on the dissociation of ankyrin B (ANK220)
from IP3R-3 in NG-108 cells. NG-108 cells were incubated
with respective drugs and then lysed for coimmunoprecipitation (IP)
studies. (A) Time- and concentration-dependent
dissociation of ankyrin B (ANK220) from IP3R-3 by the
(+)PTZ treatment. The concentration of (+)PTZ in the top row was 100
nM. For the concentration-dependent curve, immunoblots were digitally
scanned and densitometrically analyzed by the National Institutes of
Health image program. Data were normalized to total
immunoprecipitated IP3R-3 proteins and expressed as
percentage relative to the level of coimmunoprecipitated ANK220
obtained in the absence of (+)PTZ. Note: Ten-minute treatment time for
all concentrations. Data represent mean ± SEM from two to four
separate determinations. (B) Effects of selective Sig-1R
ligands on ANK220 coupling to IP3R-3. Sig-1R agonists (100
nM, 10 min) decreased the amount of ANK220 coimmunoprecipitated with
IP3R-3 without altering the level of IP3R-3.
NE-100 (100 nM), a Sig-1R antagonist, did not by itself affect the
ANK220 dissociation from IP3R-3. (C)
Inhibition of (+)PTZ-induced ANK220 dissociation from
IP3R-3 by NE-100. NE-100 (100 nM) was applied 5 min before
(+)PTZ (100 nM, 10 min). Data were analyzed as described in
A and represent mean ± SEM from six to seven
separate determinations. *, P < 0.05
compared with “control”; ##, P < 0.01
compared with “NE-100 + (+)PTZ”.