PACS-1 Mediates Phosphorylation-Dependent Ciliary Trafficking of the Cyclic-Nucleotide-Gated Channel in Olfactory Sensory Neurons

J Neurosci. 2009 Aug 26;29(34):10541-51. doi: 10.1523/JNEUROSCI.1590-09.2009.

Abstract

Impaired ciliary protein transport in olfactory sensory neurons (OSNs) leads to anosmia, and is a newly recognized clinical manifestation of a class of human disorders called ciliopathies. Surprisingly little is known regarding the mechanisms controlling trafficking to this unique neuronal compartment. Here, we show a novel role for phosphofurin acidic cluster-sorting protein 1 (PACS-1) in the ciliary trafficking of the olfactory cyclic-nucleotide-gated (CNG) channel. PACS-1 is an intracellular sorting protein that mediates its effects through the binding of acidic clusters on cargo protein. This interaction is dependent on CK2 phosphorylation of both PACS-1 and its cargo. We show that CNGB1b contains two putative PACS-1 binding sites, which are phosphorylated by the serine/threonine protein kinase, CK2. Additionally, we show that PACS-1 is expressed in OSNs and interacts in complex with the CNG channel. CK2 inhibition in native OSNs causes a loss of CNG channel from cilia and subsequent olfactory dysfunction, while adenoviral expression of mutant PACS-1 causes similar mislocalization. These results provide a mechanism for the subunit-dependent ciliary trafficking of the CNG channel and offer insight into the mechanisms of ciliary transport.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alanine / genetics
  • Animals
  • Casein Kinase II / metabolism
  • Cell Line, Transformed
  • Cilia / metabolism
  • Cyclic Nucleotide-Gated Cation Channels / classification
  • Cyclic Nucleotide-Gated Cation Channels / metabolism*
  • Dogs
  • Enzyme Inhibitors / pharmacology
  • Green Fluorescent Proteins / genetics
  • Humans
  • Immunoprecipitation
  • Mice
  • Mice, Transgenic
  • Mutation / genetics
  • Olfactory Mucosa / cytology*
  • Phosphorylation / physiology
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Protein Transport / physiology
  • RNA Interference / physiology
  • RNA, Messenger / metabolism
  • Sensory Receptor Cells / physiology*
  • Serine / genetics
  • Transfection
  • Triazoles / pharmacology
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / physiology*

Substances

  • 4,5,6,7-tetrabromobenzotriazole
  • Cyclic Nucleotide-Gated Cation Channels
  • Enzyme Inhibitors
  • PACS1 protein, human
  • Protein Subunits
  • RNA, Messenger
  • Triazoles
  • Vesicular Transport Proteins
  • Green Fluorescent Proteins
  • Serine
  • Casein Kinase II
  • Alanine