ADP/ATP Translocase 1 Was Glycosylated and Its Underglycosylation Was Associated with High Risk of Parkinson's Disease

Background: Aberrant glycosylation of proteins has major implications for human diseases. To evaluate whether the protein glycosylation has an etiological implication for Parkinson's disease (PD), a neurodegenerative disorder, we established PD mouse model treated by 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Methods: The PD mice were verified by measuring the impairment of motor function, and the reduction of the representative biological markers related to PD including dopamine, 5-hydroxytryptamine, tyrosine hydroxylase and α-synuclein. Glycosylation alteration was accessed using biotinylated Lectin of Dolichos Biflorus Agglutinin (DBA) specific for exposed N-acetylgalactosame. Findings: A glycoprotein with a significantly reduced glycosylation was revealed by immunoblotting identification blotted with DBA, and identified as ADP/ATP translocase 1 (ANT1) by lectin affinity charomatography coupled with MALDI-TOF MS/MS (mass spectrometry). In suit dual co-immunofluorescence analysis and Western blot using anti-ANT1 antibody as a probe confirmed that ANT1 was the interest glycoprotein containing the exposed N-acetylgalactosamine. Furthermore, a dramatic decrease of ANT1 in striatum, hippocampus, midbrain and brain stem, a increase in cortex, and no difference in cerebellum, was found in MPTP induced mice. Interpretation: We firstly described ANT1 as a glycoprotein containing N-acetylgalactosamine, and ANT1 was underglycosylated in nigrostriatal region of the MPTP induced PD mice. This suggested the underglycosylated ANT1 was highly correlated with PD pathogenesis. This investigation potentially promoted an innovative understanding of the protein glycosylation on the etiology of PD and provided valuable information on developing potential drug targets in PD treatment or reliable biomarkers in PD prognostication.   Funding Statement: This work was supported in part by National Natural Science Foundation of China (81272429) and Liaoning Provincial Program for Top Discipline of Basic Medical Sciences. Declaration of Interests: The authors declare no conflict of interest. Ethics Approval Statement: This study was carried out in accordance with the principles of the Basel Declaration and recommendations of Dalian Medical University for laboratory animals. The protocol was approved by the Animal Ethics Committee of Dalian Medical University.