PKA and PDE4D3 anchoring to AKAP9 provides distinct regulation of cAMP signals at the centrosome.
Previous work has shown that the protein kinase A (PKA)-regulated phosphodiesterase (PDE) 4D3 binds to A kinase-anchoring proteins (AKAPs). One such protein, AKAP9, localizes to the centrosome. In this paper, we investigate whether a PKA-PDE4D3-AKAP9 complex can generate spatial compartmentalization of cyclic adenosine monophosphate (cAMP) signaling at the centrosome. Real-time imaging of fluorescence resonance energy transfer reporters shows that centrosomal PDE4D3 modulated a dynamic microdomain within which cAMP concentration selectively changed over the cell cycle. AKAP9-anchored, centrosomal PKA showed a reduced activation threshold as a consequence of increased autophosphorylation of its regulatory subunit at S114. Finally, disruption of the centrosomal cAMP microdomain by local displacement of PDE4D3 impaired cell cycle progression as a result of accumulation of cells in prophase. Our findings describe a novel mechanism of PKA activity regulation that relies on binding to AKAPs and consequent modulation of the enzyme activation threshold rather than on overall changes in cAMP levels. Further, we provide for the first time direct evidence that control of cell cycle progression relies on unique regulation of centrosomal cAMP/PKA signals.
Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
Anna
A
Terrin
Stefania
S
Monterisi
Alessandra
A
Stangherlin
Anna
A
Zoccarato
Andreas
A
Koschinski
Nicoletta C
NC
Surdo
Marco
M
Mongillo
Akira
A
Sawa
Niove E
NE
Jordanides
Joanne C
JC
Mountford
Manuela
M
Zaccolo
D054758:A Kinase Anchor Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D020134:Catalytic Domain / Q000502:physiology*; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D018385:Centrosome / Q000502:physiology*; D006224:Cricetinae; D000242:Cyclic AMP / Q000502:physiology*; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4 / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015398:Signal Transduction / Q000502:physiology*
D054758:A Kinase Anchor Proteins; C119719:AKAP9 protein, human; D003598:Cytoskeletal Proteins; D000242:Cyclic AMP; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits; D017868:Cyclic AMP-Dependent Protein Kinases; C517757:PRKACA protein, human; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4