title: Are Wnts Retrogradely Transported to the ER?
abstract: A recent report showed that Drosophila miR-307a initiates endoplasmic reticulum (ER) stress in wingless (wg)-expressing cells by suppression of the evolutionarily conserve Wnt secretion factor Wntless (Wls). Interestingly, the authors noted that wg has a putative C-terminal dilysine motif (KKVY), which is required for its apparent retrograde Golgi-to-ER transport. Wls suppression resulted in ER stress, which was phenocopied by several other manipulations that impaired wg secretion in flies, as well as Wnt5a secretion in mammalian cells. The authors surmised that their data "reveals a previously unknown Golgi-to-ER retrograde route of wg, and elucidates a correlation between Wnt secretion and ER stress." However, there are obvious caveats to this interpretation, as ER stress resulting from Wnt secretion impairment could be readily explained by its inability to leave the ER, and not resulting from Golgi-to-ER retrograde transport. J. Cell. Physiol. 231: 2315-2316, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.
authors.forename: Bor Luen
authors.initials: BL
authors.lastname: Tang
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D021381:Protein Transport; D051153:Wnt Proteins / Q000378:metabolism*
chemical_list: D051153:Wnt Proteins