Article Figures & Data
Figures
- Figure 1.
PKA activation induces Kv4.2g redistribution in hippocampal neurons. A, Representative images show that AMPA (50 μm) or FSK (10 μm) treatment causes Kv4.2 redistribution from dendritic spines. B, Summary plot shows a significant decrease in the percentage of spines containing Kv4.2g after AMPA (n = 10 neurons, 1296 spines) or FSK (n = 19 neurons, 2372 spines) treatment relative to control (n = 18 neurons, 2163 spines). All data are mean ± SE. *p < 0.001.
- Figure 2.
PKA activation elicits Kv4.2myc internalization in hippocampal neurons. A, Representative images show internalized Kv4.2myc channels (green) and surface-remaining Kv4.2myc channels (red) after AMPA (100 μm), FSK (10 μm), or 8-Br-cAMP (100 μm) treatment. B, Summary plot shows a significant increase in the intensity ratio (green integrated intensity/total integrated intensity) after AMPA (n = 11), FSK (n = 16), or 8-Br-cAMP (n = 10) treatments, relative to control (n = 29). C, In cultured hippocampal neurons, endogenous IA peak amplitude is reduced after AMPA (50 μm; n = 12), FSK (10 μm; n = 14), or 8-Br-cAMP (50 μm; n = 18) treatment, and no changes in sustained current peak amplitudes after any treatment were observed (p > 0.30). Open bars, Pretreatment recordings; gray bars, posttreatment recordings. Calibration: 50 pA, 100 ms. D, The cell-surface biotinylation experiment in acute hippocampal slices demonstrates that surface expression of endogenous Kv4.2 is reduced 37 ± 0.09% after FSK (10 μm; n = 3) treatment compared with control (Cont; n = 3). All data are mean ± SE. *p < 0.05.
- Figure 3.
PKA inhibition blocks Kv4.2myc activity-dependent internalization. A, Representative images showing internalized Kv4.2myc channels (green) and surface-remaining Kv4.2myc channels (red) after H89 (10 μm) pretreatment and AMPA (50 μm) stimulation in hippocampal neurons. B, Summary plot shows that the increase in intensity ratio (green integrated intensity/total integrated intensity) after AMPA treatment (n = 14) is prevented by pretreatment with H89 (n = 19). No differences (p > 0.05) were found between control (n = 23), H89 + AMPA (n = 19), and H89 alone (n = 13). All data are mean ± SE. *p < 0.001.
- Figure 4.
Kv4.2 internalization requires PKA phosphorylation at Ser 552. A, Representative images show that AMPA (50 μm) does not induce redistribution of Kv4.2gS552A from dendritic spines. AMPA treatment (n = 23 neurons, 1908 spines) had no effect on the percentage of spines containing Kv4.2gS552A (92.17 ± 1.49%), compared with control (93.89 ± 0.87%; n = 25 neurons, 3247 spines; p = 0.33). B, FSK (10 μm; n = 6) significantly reduces the peak current density of IA compared with untreated cultured neurons expressing Kv4.2g (Cont; n = 8; *p < 0.05). This effect was not observed in cultured neurons expressing Kv4.2S552A (Cont, n = 6; FSK, n = 8; p = 0.65). All data are mean ± SE.
Additional Files
Supplemental Data
Files in this Data Supplement:
- supplemental material - Supplemental Figure 1
- supplemental material - Supplemental Figure 2
