Fig. 3
Spatial training and NMDA injection both increase Smad4 SUMOylation. a Rats either received water maze training for 4 days or served as swimming controls. They were sacrificed at the end of training and their CA1 tissue was subjected to Smad4 SUMOylation determination. Left panel: Immunoprecipitated with anti-Smad4 antibody and immunoblotted with anti-Smad4 antibody. Right panel: The membrane was stripped and further immunoblotted with anti-SUMO1 antibody. b Quantified results. n = 6 for each group, t(1,10) = 17.45, # P < 0.001, Student’s t-test. c Animals received an injection of PBS or NMDA (8 mM) to the CA1 area of their brains and were sacrificed 30 min or 60 min later. Their CA1 tissue was subjected to Smad4 SUMOylation assay and pERK1, pERK2, ERK1, and ERK2 determinations. Upper left panel: Immunoblotted with anti-Smad4 antibody. Right panel: The membrane was stripped and further immunoblotted with anti-SUMO1 antibody. Lower-left panel: Representative gel pattern of pERK1, pERK2, ERK1, and ERK2 western blot. d Quantified result of Smad4 SUMOylation. n = 6 for each group, F(2,15) = 220.72, # P < 0.001; q = 12.03, # P < 0.001 comparing the PBS and NMDA 30 min groups; q = 29.54, # P < 0.001 comparing the PBS and NMDA 60 min groups; q = 17.52, # P < 0.001 comparing the NMDA 30 min and NMDA 60 min groups. e Quantified result of pERK1/ERK1. n = 6 for each group, F(2,15) = 65.36, # P < 0.001; q = 15.14, # P < 0.001 comparing the PBS and NMDA 30 min groups; q = 12.48, # P < 0.001 comparing the NMDA 30 min and NMDA 60 min groups. f Quantified result of pERK2/ERK2. n = 6 for each group, F(2,15) = 27.71, # P < 0.001; q = 9.9, # P < 0.001 comparing the PBS and NMDA 30 min groups; q = 8.05, # P < 0.001 comparing the NMDA 30 min and NMDA 60 min groups. Data are expressed as means ± SEMs. IB immunoblotting, IP immunoprecipitation, PBS phosphate-buffered saline, SEM standard error of the mean