RT Journal Article SR Electronic T1 In vivo assembly and trafficking of olfactory Ionotropic Receptors JF bioRxiv FD Cold Spring Harbor Laboratory SP 441782 DO 10.1101/441782 A1 Liliane Abuin A1 Lucia L. Prieto-Godino A1 Haiyun Pan A1 Craig Gutierrez A1 Lan Huang A1 Rongsheng Jin A1 Richard Benton YR 2018 UL http://biorxiv.org/content/early/2018/10/12/441782.abstract AB lonotropic Receptors (IRs) are a large, divergent subfamily of ionotropic glutamate receptors(iGluRs), with roles in chemosensation, thermosensation and hygrosensation. Analogous to the synaptic targeting mechanisms of their iGluR ancestors, IRs are thought to form complexes of broadly-expressed co-receptors and selectively-expressed ‘tuning’ receptors to localise to sensory cilia. While tuning receptors’ extracellular ligand-binding domain (LBD) defines sensory specificity, the role of this domain in co-receptors is unclear. We identify a coreceptor-specific sequence in the LBD, which contains a single N-glycosylation site. Combining molecular genetic and cell biological analyses, we show that this site is dispensable for assembly of IR complexes in olfactory sensory neurons, but essential for endoplasmic reticulum exit of some,but not all, IR complexes. Our data reveal an important role for the IR co-receptor LBD in control of intracellular transport, provide novel insights into the stoichiometry and assembly of IR complexes, and uncover an unexpected heterogeneity in the trafficking regulation of this sensory receptor family.