RISC assembly defects in the Drosophila RNAi mutant armitage.
The putative RNA helicase, Armitage (Armi), is required to repress oskar translation in Drosophila oocytes; armi mutant females are sterile and armi mutations disrupt anteroposterior and dorsoventral patterning. Here, we show that armi is required for RNAi. armi mutant male germ cells fail to silence Stellate, a gene regulated endogenously by RNAi, and lysates from armi mutant ovaries are defective for RNAi in vitro. Native gel analysis of protein-siRNA complexes in wild-type and armi mutant ovary lysates suggests that armi mutants support early steps in the RNAi pathway but are defective in the production of active RNA-induced silencing complex (RISC), which mediates target RNA destruction in RNAi. Our results suggest that armi is required for RISC maturation.
Tomari
Yukihide
Y
Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
Du
Tingting
T
Haley
Benjamin
B
Schwarz
Dianne S
DS
Bennett
Ryan
R
Cook
Heather A
HA
Koppetsch
Birgit S
BS
Theurkauf
William E
WE
Zamore
Phillip D
PD
D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D005260:Female; D005854:Germ Cells / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics; D008297:Male; D009154:Mutation / Q000235:genetics*; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics; D020365:RNA Helicases / Q000172:deficiency* / Q000235:genetics; D034622:RNA Interference / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D034743:RNA-Induced Silencing Complex / Q000096:biosynthesis* / Q000235:genetics
D029721:Drosophila Proteins; D019476:Insect Proteins; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex; C091675:osk protein, Drosophila; D011494:Protein Kinases; C094331:Ste protein, Drosophila; D020365:RNA Helicases