Involvement of DARPP-32 phosphorylation in the stimulant action of caffeine.
Caffeine has been imbibed since ancient times in tea and coffee, and more recently in colas. Caffeine owes its psychostimulant action to a blockade of adenosine A(2A) receptors, but little is known about its intracellular mechanism of action. Here we show that the stimulatory effect of caffeine on motor activity in mice was greatly reduced following genetic deletion of DARPP-32 (dopamine- and cyclic AMP-regulated phosphoprotein of relative molecular mass 32,000). Results virtually identical to those seen with caffeine were obtained with the selective A(2A) antagonist SCH 58261. The depressant effect of the A(2A) receptor agonist, CGS 21680, on motor activity was also greatly attenuated in DARPP-32 knockout mice. In support of a role for DARPP-32 in the action of caffeine, we found that, in striata of intact mice, caffeine increased the state of phosphorylation of DARPP-32 at Thr 75. Caffeine increased Thr 75 phosphorylation through inhibition of PP-2A-catalysed dephosphorylation, rather than through stimulation of cyclin-dependent kinase 5 (Cdk5)-catalysed phosphorylation, of this residue. Together, these studies demonstrate the involvement of DARPP-32 and its phosphorylation/dephosphorylation in the stimulant action of caffeine.
Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
Maria
M
Lindskog
Per
P
Svenningsson
Laura
L
Pozzi
Yong
Y
Kim
Allen A
AA
Fienberg
James A
JA
Bibb
Bertil B
BB
Fredholm
Angus C
AC
Nairn
Paul
P
Greengard
Gilberto
G
Fisone
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects; D017072:Neostriatum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009419:Nerve Tissue Proteins; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D010627:Phenethylamines / Q000494:pharmacology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D010769:Phosphothreonine / Q000378:metabolism; D058915:Purinergic P1 Receptor Antagonists; D011743:Pyrimidines / Q000494:pharmacology; D018047:Receptors, Purinergic P1 / Q000378:metabolism; D014230:Triazoles / Q000494:pharmacology
C098657:5-amino-7-(2-phenylethyl)-2-(2-furyl)pyrazolo(4,3-e)-1,2,4-triazolo(1,5-c)pyrimidine; D000697:Central Nervous System Stimulants; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D009419:Nerve Tissue Proteins; D010627:Phenethylamines; D010750:Phosphoproteins; D058915:Purinergic P1 Receptor Antagonists; D011743:Pyrimidines; D018047:Receptors, Purinergic P1; D014230:Triazoles; D010769:Phosphothreonine; C061282:2-(4-(2-carboxyethyl)phenethylamino)-5'-N-ethylcarboxamidoadenosine; D002110:Caffeine; D051360:Cyclin-Dependent Kinase 5; C495906:Cdk5 protein, mouse; D018844:Cyclin-Dependent Kinases; D000241:Adenosine