Alpha-synuclein interferes with cAMP/PKA-dependent upregulation of dopamine β-hydroxylase and is associated with abnormal adaptive responses to immobilization stress 

Sasuk Kim, Ji-Min Park, Jisook Moon, Hyun Jin Choi

Experimental Neurology, v.252 p.63~74, doi:10.1016/j.expneurol.2013.11.009

ABSTRACT

Parkinson's disease (PD) is clinically characterized not only by motor symptoms but also by non-motor symptoms, such as anxiety and mood changes. Based on our previous study showing that overexpression of wild-type or mutant α-synuclein (α-SYN) interferes with cAMP/PKA-dependent transcriptional activation in norepinephrine (NE)-producing cells, the effect of wild-type and mutant α-SYN on cAMP response element (CRE)-mediated regulation of the NE-synthesizing enzyme dopamine β-hydroxylase (DBH) was evaluated in this study. Overexpression of wild-type or mutant α-SYN interfered with CRE-mediated regulation of DBH transcription in NE-producing SK-N-BE(2) cells. Upon entering the nucleus, α-SYN interacted with the DBH promoter region encompassing the CRE, which interfered with forskolin-induced CREB binding to the CRE region. Interestingly, mutant A53T α-SYN showed much higher tendency to nuclear translocation and interaction with the DBH promoter region encompassing the CRE than wild type. In addition, A53T α-SYN expressing transgenic mice exhibited increased anxiety-like behaviors under normal conditions and abnormal regulation of DBH expression in response to immobilization stress with abnormal adaptive responses. These data provide an insight into the physiological function of α-SYN in NErgic neuronal cells, which further indicates that the α-SYN mutation may play a causative role in the generation of non-motor symptoms in PD.

* Keyword: α-Synuclein, Anxiety, cAMP, Dopamine β-hydroxylase (DBH), Parkinson's disease, Stress

- PMID: 24252179

- Fulltext: http://www.sciencedirect.com/science/article/pii/S0014488613003336