Figure 4.

CaMKII, but not PKA, regulates increases in proteasome activity following fear conditioning. Rats received infusions of a PKA inhibitor (myr-PKI), CaMKII inhibitor (myr-AIP) or vehicle immediately after fear conditioning and amygdala tissue was collected 4 h later (n = 8–10 per group). (A) Inhibiting PKA had no effect on proteasome activity, while inhibiting CaMKII significantly reduced proteasome chymotrypsin-like activity relative to vehicle infused trained rats. (B) Inhibiting CaMKII, but not PKA, reduced proteasome peptidylglutamyl-peptide hydrolyzing-like activity. (C) Neither inhibitor altered proteasome trypsin-like activity. ^*p < 0.05 from vehicle. ^#P = 0.07 from vehicle.