VPS35 regulates cell surface recycling and signaling of dopamine receptor D1

Neurobiol Aging. 2016 Oct;46:22-31. doi: 10.1016/j.neurobiolaging.2016.05.016. Epub 2016 May 21.

Abstract

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.

Keywords: Dopamine; Dopamine receptor D1; Dopamine signaling; Parkinson's disease; Trafficking; Vacuolar protein sorting 35.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Dopaminergic Neurons / metabolism*
  • Dopaminergic Neurons / pathology
  • Dopaminergic Neurons / physiology*
  • Epistasis, Genetic
  • HEK293 Cells
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mutation*
  • Parkinson Disease / genetics*
  • Parkinson Disease / pathology
  • Receptors, Dopamine D1 / metabolism*
  • Receptors, Dopamine D1 / physiology
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • Tumor Cells, Cultured
  • Vesicular Transport Proteins / deficiency
  • Vesicular Transport Proteins / genetics*
  • Vesicular Transport Proteins / physiology*

Substances

  • DRD1 protein, human
  • Receptors, Dopamine D1
  • VPS35 protein, human
  • Vesicular Transport Proteins