RIC-3 affects properties and quantity of nicotinic acetylcholine receptors via a mechanism that does not require the coiled-coil domains.

Members of the RIC-3 gene family are effectors of nicotinic acetylcholine receptor (nAChR) expression in vertebrates and invertebrates. In Caenorhabditis elegans RIC-3 is needed for functional expression of multiple nAChRs, including the DEG-3/DES-2 nAChR. Effects of RIC-3 on DEG-3/DES-2 functional expression are found in vivo and following heterologous expression in Xenopus leavis oocytes.

Conservation within the RIC-3 gene family. Effectors of mammalian nicotinic acetylcholine receptor expression.

In Caenorhabditis elegans, the ric-3 gene is required for the maturation of multiple nicotinic acetylcholine receptors (nAChRs), whereas other neurotransmittergated channels expressed within the same cells are unaffected by the presence of RIC-3. Here we show that RIC-3 is a member of a conserved gene family with representatives in both vertebrates and invertebrates. All members of this family have two transmembrane domains followed by a coiled-coil domain.

Mutations in the extracellular domain and in the membrane-spanning domains interfere with nicotinic acetylcholine receptor maturation.

The deg-3(u662) mutation is a degeneration-causing mutation in a Caenorhabditis elegans nicotinic acetylcholine receptor. In a large screen for mutations that suppress the deleterious effects of this mutation we identified 32 mutations in the deg-3 gene. Among these, 11 are missense mutations, affecting seven residues within the extracellular domain or the membrane-spanning domains.

The C. elegans ric-3 gene is required for maturation of nicotinic acetylcholine receptors.

Mutations in ric-3 (resistant to inhibitors of cholinesterase) suppress the neuronal degenerations caused by a gain of function mutation in the Caenorhabditis elegans DEG-3 acetylcholine receptor. RIC-3 is a novel protein with two transmembrane domains and extensive coiled-coil domains. It is expressed in both muscles and neurons, and the protein is concentrated within the cell bodies.