Dopamine and the phosphorylated dopamine transporter are increased in the diacylglycerol kinase η‐knockout mouse brain
It is found that DGKη knockout markedly increased dopamine levels in the midbrain and cerebral cortex and significantly augmented phosphorylated DA transporter (DAT) levels, which induce DA efflux to the synaptic cleft, in the cerebral cortex.
Abstract
The molecular mechanisms generating the mania‐like abnormal behaviors caused by diacylglycerol (DG) kinase (DGK) η deficiency remain unclear. Here, we found that DGKη knockout markedly increased dopamine (DA) levels in the midbrain (DA‐producing region, 2.8‐fold) and cerebral cortex (DA projection region, 1.2‐fold). Moreover, DGKη deficiency significantly augmented phosphorylated DA transporter (DAT) levels (1.4‐fold increase), which induce DA efflux to the synaptic cleft, in the cerebral cortex. Moreover, phosphorylation levels of protein kinase C‐β, which is activated by DG and involved in DAT phosphorylation, were also increased. DAT expressed in Neuro‐2a cells recruited DGKη to the plasma membrane and colocalized with it. These results strongly suggest that dopaminergic hyperfunction caused by DGKη deficiency in the brain leads to mania‐like behaviors.