Figure 3.

Activation of the PKA pathway by cAMP protects RGS13 from degradation. (A) HEK293T cells were transfected with pEGFP-RGS13 together with empty vector or a plasmid encoding PKI. After 24 h, cells were stimulated with 8-pCPT-cAMP (2 mM) or vehicle in the presence of CHX for the indicated time periods. Cell lysates were prepared and analyzed by immunoblotting using anti-RGS13 and anti-β-actin antibodies. (B) Densitometric analysis of RGS13 levels normalized by β-actin levels (mean ± SEM from three to five independent experiments; P < 0.001 for RGS13 in the presence and absence of cAMP, Student's t-test).