RESUMO
The neuronal dopamine transporter (DAT) is a presynaptic plasma membrane protein mediating the re-uptake of dopamine released from synaptic cleft into the nerve terminals. While the regulation of its activity by protein kinase C signalling is well-characterized, there is controversial debate about its regulation by protein kinase A (PKA) signalling. In rat striatal synaptosomes, we showed that a cell-permeable cyclic adenosine 3',5'-monophosphate analogue up-regulated the DAT capacity without modification of its efficiency. This acute effect was PKA-, calcium calmodulin dependent kinase II- and phosphatase-dependent. Together, these results suggest that the activity of DAT may depend on a state of the transporter with both specific phosphorylated and dephosphorylated sites.
