In vitro PKA phosphorylation‐mediated human PDE4A4 activation
F Laliberté, S Liu, E Gorseth, B Bobechko… - FEBS …, 2002 - Wiley Online Library
F Laliberté, S Liu, E Gorseth, B Bobechko, A Bartlett, P Lario, MJ Gresser, Z Huang
FEBS letters, 2002•Wiley Online LibraryThe PDE4 catalytic machinery comprises, in part, two divalent cations in a binuclear motif.
Here we report that PDE4A4 expressed in Sf9 cells exhibits a biphasic Mg2+ dose–
response (EC50 of∼ 0.15 and> 10 mM) in catalyzing cAMP hydrolysis. In vitro
phosphorylation of PDE4A4 by the PKA‐catalytic subunit increases the enzyme's sensitivity
to Mg2+, leading to 4‐fold increased cAMP hydrolysis without affecting its K m. The
phosphorylation also increases the potencies of (R)‐and (S)‐rolipram without affecting CDP …
Here we report that PDE4A4 expressed in Sf9 cells exhibits a biphasic Mg2+ dose–
response (EC50 of∼ 0.15 and> 10 mM) in catalyzing cAMP hydrolysis. In vitro
phosphorylation of PDE4A4 by the PKA‐catalytic subunit increases the enzyme's sensitivity
to Mg2+, leading to 4‐fold increased cAMP hydrolysis without affecting its K m. The
phosphorylation also increases the potencies of (R)‐and (S)‐rolipram without affecting CDP …
The PDE4 catalytic machinery comprises, in part, two divalent cations in a binuclear motif. Here we report that PDE4A4 expressed in Sf9 cells exhibits a biphasic Mg2+ dose–response (EC50 of ∼0.15 and >10 mM) in catalyzing cAMP hydrolysis. In vitro phosphorylation of PDE4A4 by the PKA‐catalytic subunit increases the enzyme's sensitivity to Mg2+, leading to 4‐fold increased cAMP hydrolysis without affecting its K m. The phosphorylation also increases the potencies of (R)‐ and (S)‐rolipram without affecting CDP‐840 and SB‐207499. The results support that modulating the cofactor binding affinity of PDE4 represents a mechanism for regulating its activity.
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