TRP and rhodopsin transport depends on dual XPORT ER chaperones encoded by an operon

TitleTRP and rhodopsin transport depends on dual XPORT ER chaperones encoded by an operon
Publication TypeJournal Article
Year of Publication2015
AuthorsChen Z, Chen H-C, Montell C
JournalCell Rep
Volume13
Pagination573-84
Date Published2015 Oct 20
ISSN2211-1247
Abstract

TRP channels and G protein-coupled receptors (GPCRs) play critical roles in sensory reception. However, the identities of the chaperones that assist GPCRs in translocating from the endoplasmic reticulum (ER) are limited, and TRP ER chaperones are virtually unknown. The one exception for TRPs is Drosophila XPORT. Here, we show that the xport locus is bicistronic and encodes unrelated transmembrane proteins, which enable the signaling proteins that initiate and culminate phototransduction, rhodopsin 1 (Rh1) and TRP, to traffic to the plasma membrane. XPORT-A and XPORT-B are ER proteins, and loss of either has a profound impact on TRP and Rh1 targeting to the light-sensing compartment of photoreceptor cells. XPORT-B complexed in vivo with the Drosophila homolog of the mammalian HSP70 protein, GRP78/BiP, which, in turn, associated with Rh1. Our work highlights a coordinated network of chaperones required for the biosynthesis of the TRP channel and rhodopsin in Drosophila photoreceptor cells.

DOI10.1016/j.celrep.2015.09.018
Alternate JournalCell Rep
PubMed ID26456832
PubMed Central IDPMC4618092
Grant ListR01 EY008117 / EY / NEI NIH HHS / United States
R01 EY010852 / EY / NEI NIH HHS / United States