Cell Surface Expression of 5-Hydroxytryptamine Type 3 Receptors Is Promoted by RIC-3

Aixin Cheng, Neil A. McDonald, Christopher N. Connolly
2005 Journal of Biological Chemistry  
RIC-3 has been identified as a molecule essential for the recruitment of functional nicotinic acetylcholine receptors composed of ␣7, but it exhibits inhibitory effects on ␣4␤2 or ␣3␤4 receptors. In this study, we investigated the role of RIC-3 in the recruitment of 5-hydroxytryptamine type 3A (5-HT 3A ) receptors to the cell surface. Although RIC-3 is not essential for the surface transport of 5-HT 3A receptors, we found that its presence enhances both receptor transport and function in a
more » ... function in a concentration-dependent manner. RIC-3 is localized to the endoplasmic reticulum, as evidenced by co-localization with the chaperone molecule, binding protein (BiP). RIC-3 is not detected at significant levels on the cell surface when expressed alone or in the presence of 5-HT 3A . RIC-3 and 5-HT 3A show a low level interaction that is transient (<4 h). That RIC-3 can interact with an endoplasmic reticulum-retained 5-HT 3A construct, combined with the transient interaction observed and lack of significant surface-expressed RIC-3, suggests that RIC-3 may play a role in 5-HT 3A receptor folding, assembly, or transport to the cell surface.
doi:10.1074/jbc.m414341200 pmid:15809299 fatcat:rkev73fvajarhkcmmkgp4aubgq