Anti-VPS35 (aa 400-500) polyclonal antibody Knockout Validated

Vacuolar protein sorting 35 (VPS35) is a retromer complex component regulating membrane protein trafficking and retrieval. Mutations or dysfunction of VPS35 have been linked to Parkinson's disease (PD), which is pathologically characterized by the loss of dopamine neurons in brain substantia nigra region. Dopamine plays a key role in regulating various brain physiological functions by binding to its receptors and triggering their endocytosis and signaling pathways. However, it is unclear whether there is a link between VPS35 and dopamine signaling in PD. Herein, we found that VPS35 interacted with dopamine receptor D1 (DRD1). Notably, overexpression and downregulation of VPS35 increased and decreased steady-state cell surface levels of DRD1 and phosphorylation of cAMP-response element binding protein (CREB) and extracellular regulated protein kinases (ERK) that are important dopamine signaling effectors, respectively. In addition, overexpression of VPS35 promoted cell surface recycling of endocytic DRD1. Furthermore, downregulation of VPS35 abolished dopamine-induced CREB/ERK phosphorylation. More importantly, although the PD-associated VPS35 mutant VPS35 (D620N) still interacted with DRD1, its expression did not affect cell surface recycling of DRD1 and phosphorylation of CREB/ERK nor rescue the reduction of CREB/ERK phosphorylation caused by VPS35 downregulation. These results demonstrate that VPS35 regulates DRD1 trafficking and DRD1-mediated dopamine signaling pathway, and that the PD-associated VPS35 (D620N) mutant loses such functions, providing a novel molecular mechanism underlying PD pathogenesis. (C) 2016 Elsevier Inc. All rights reserved.

Although Parkinson's disease (PD) was considered to be a textbook example of a non-genetic condition until the mid 1990s, at least 8 forms of monogenic parkinsonism have been identified in the past 15 years that can be clinically indistinguishable from idiopathic Parkinson's disease. Whereas the currently known PD gene collectively explains only about 5% of all PD cases in Germany, about 5000 of the 100000 German PD patients will have a genetic cause underlying their disease. Major technical advances have been paralleled by a decrease in costs for genetic testing; thus, molecular genetic tests for all known PD genes are offered by certified laboratories in Germany. There are no guidelines for genetic testing for PD; a genetic test should be considered in cases of an early age of disease onset, a specific ethnic background and a positive family history. A careful description of the phenomenology and the putative mode of inheritance is the first step in the diagnosis of a specific form of (hereditary) parkinsonism and the basis for an informed step-wise analysis. A negative test result does not exclude a genetic form. Molecular testing for genetic parkinsonism should be considered in carefully selected cases and may have an important impact on patients despite the current lack of a specific or neuroprotective therapy. This may affect diagnostic procedures, prognostic considerations, family and career planning and even therapeutic approaches. However, a profound change in our view of the role of genetic testing for PD will depend on the advent of neuroprotective therapies.