title: RNAi screening of Drosophila (Sophophora) melanogaster S2 cells for ricin sensitivity and resistance.
abstract: The ribosome-inhibiting toxin ricin binds exposed β1→4 linked galactosyls on multiple glycolipids and glycoproteins on the cell surface of most eukaryotic cells. After endocytosis, internal cell trafficking is promiscuous, with only a small proportion of ricin proceeding down a productive (cytotoxic) trafficking route to the endoplasmic reticulum (ER). Here, the catalytic ricin A chain traverses the membrane to inactivate the cytosolic ribosomes, which can be monitored by measuring reduction in protein biosynthetic capacity or cell viability. Although some markers have been discovered for the productive pathway, many molecular details are lacking. To identify a more comprehensive set of requirements for ricin intoxication, the authors have developed an RNAi screen in Drosophila S2 cells, screening in parallel the effects of individual RNAi treatments alone and when combined with a ricin challenge. Initial screening of 806 gene knockdowns has revealed a number of candidates for both productive and nonproductive ricin trafficking, including proteins required for transport to the Golgi, plus potential toxin interactors within the ER and cytosol.
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry, UK.
authors.forename: Vidya
authors.initials: V
authors.lastname: Pawar
authors.forename: Antara
authors.initials: A
authors.lastname: De
authors.forename: Laura
authors.initials: L
authors.lastname: Briggs
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Omar
authors.forename: Sean T
authors.initials: ST
authors.lastname: Sweeney
authors.forename: J Michael
authors.initials: JM
authors.lastname: Lord
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Roberts
authors.forename: Robert A
authors.initials: RA
authors.lastname: Spooner
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Moffat
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002619:Chemical Warfare Agents / Q000494:pharmacology; D004331:Drosophila melanogaster / Q000166:cytology / Q000187:drug effects* / Q000235:genetics*; D004351:Drug Resistance / Q000235:genetics; D015723:Gene Library; D057166:High-Throughput Screening Assays; D034622:RNA Interference; D012276:Ricin / Q000494:pharmacology*
chemical_list: D002619:Chemical Warfare Agents; D012276:Ricin