RIC-3: a nicotinic acetylcholine receptor chaperone

Br J Pharmacol. 2008 Mar;153 Suppl 1(Suppl 1):S177-83. doi: 10.1038/sj.bjp.0707661. Epub 2008 Feb 4.


RIC-3 is a transmembrane protein which acts as a molecular chaperone of nicotinic acetylcholine receptors (nAChRs). For some nAChR subtypes (such as homomeric alpha7 neuronal nAChRs), RIC-3 is required for efficient receptor folding, assembly and functional expression. In contrast, for other nAChR subtypes (such as heteromeric alpha4beta2 neuronal nAChRs) there have been reports that RIC-3 can both enhance and reduce levels of functional expression. There is also evidence that RIC-3 can modulate maturation of the closely related 5-hydroxytryptamine (5-HT) receptor (5-HT(3)R). As with heteromeric nAChRs, apparently contradictory results have been reported for the influence of RIC-3 on 5-HT(3)R maturation in different expression systems. Recent evidence indicates that these differences in RIC-3 chaperone activity may be influenced by the host cell, suggesting that other proteins may play an important role in modulating the effects of RIC-3 as a chaperone. RIC-3 was originally identified in the nematode Caenorhabditis elegans as the protein encoded by the gene ric-3 (resistance to inhibitors of cholinesterase) and has subsequently been cloned and characterized from mammalian and insect species. This review provides a brief history of RIC-3; from the identification of the ric-3 gene in C. elegans in 1995 to the more recent demonstration of its activity as a nAChR chaperone.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / physiology*
  • Molecular Chaperones / genetics
  • Molecular Chaperones / physiology*
  • Parasympathetic Nervous System / physiology
  • Receptors, Nicotinic / genetics
  • Receptors, Nicotinic / physiology*
  • Signal Transduction
  • Subcellular Fractions


  • Intracellular Signaling Peptides and Proteins
  • Molecular Chaperones
  • RIC3 protein, human
  • Receptors, Nicotinic