Munsie L N, Milnerwood A J, Seibler P, Beccano-Kelly D A, Tatarnikov I, Khinda J, Volta M, Kadgien C, Cao L P, Tapia L, Klein C, Farrer M J
Department Medical Genetics, Centre for Applied Neurogenetics, Djavad Mowafagian Centre for Brain Health, Vancouver, Canada.
Department Medical Genetics, Centre for Applied Neurogenetics, Djavad Mowafagian Centre for Brain Health, Vancouver, Canada, Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 2B5
Hum Mol Genet. 2015 Mar 15;24(6):1691-703. doi: 10.1093/hmg/ddu582. Epub 2014 Nov 21.
Vacuolar protein sorting 35 (VPS35) is a core component of the retromer complex, crucial to endosomal protein sorting and intracellular trafficking. We recently linked a mutation in VPS35 (p.D620N) to familial parkinsonism. Here, we characterize human VPS35 and retromer function in mature murine neuronal cultures and investigate neuron-specific consequences of the p.D620N mutation. We find VPS35 localizes to dendritic spines and is involved in the trafficking of excitatory AMPA-type glutamate receptors (AMPARs). Fundamental neuronal processes, including excitatory synaptic transmission, AMPAR surface expression and synaptic recycling are altered by VPS35 overexpression. VPS35 p.D620N acts as a loss-of-function mutation with respect to VPS35 activity regulating synaptic transmission and AMPAR recycling in mouse cortical neurons and dopamine neuron-like cells produced from induced pluripotent stem cells of human p.D620N carriers. Such perturbations to synaptic function likely produce chronic pathophysiological stress upon neuronal circuits that may contribute to neurodegeneration in this, and other, forms of parkinsonism.
液泡蛋白分选蛋白35（VPS35）是逆向转运复合物的核心成分，对内体蛋白分选和细胞内运输至关重要。我们最近将VPS35中的一个突变（p.D620N）与家族性帕金森病联系起来。在此，我们在成熟的小鼠神经元培养物中表征人VPS35和逆向转运复合物的功能，并研究p.D620N突变对神经元的特异性影响。我们发现VPS35定位于树突棘，并参与兴奋性α-氨基-3-羟基-5-甲基-4-异恶唑丙酸型谷氨酸受体（AMPARs）的运输。包括兴奋性突触传递、AMPAR表面表达和突触再循环在内的基本神经元过程会因VPS35的过表达而改变。在调节小鼠皮质神经元和由人p.D620N携带者的诱导多能干细胞产生的多巴胺能神经元样细胞中的突触传递和AMPAR再循环方面，VPS35 p.D620N表现为功能丧失突变。这种对突触功能的干扰可能会给神经元回路带来慢性病理生理压力，这可能导致这种及其他形式帕金森病的神经退行性变。
