RNA-dependent RNA polymerase activity associated with endogenous double-stranded RNA in rice.
RNA-dependent RNA polymerase (RdRp) activity was detected in the crude microsomal fraction of rice cultured cells that contain a 14 kbp double-stranded RNA (dsRNA). RdRp activity is maximal in the presence of all four nucleotide triphosphates and Mg2+ ion and is resistant to inhibitors of DNA-dependent RNA polymerases (actinomycin D and alpha-amanitin). RdRp activity increases approximately 2.5-fold in the presence of 0.5% deoxycholate. Treatment of purified microsomal fraction with proteinase K plus deoxycholate suggests that the RdRp enzyme complex with its own 14 kb RNA template is located in vesicles. The RdRp enzyme complex was solubilized with Nonidet P-40 and purified by glycerol gradient centrifugation, then exogenous RNA templates were added. Results indicate that exogenous dsRNA reduces RNA synthesis from the endogenous 14 kb RNA template.
Horiuchi
H
H
Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo, 183-8509 Japan.
Udagawa
T
T
Koga
R
R
Moriyama
H
H
Fukuhara
T
T
D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D003902:Detergents / Q000494:pharmacology; D008861:Microsomes / Q000187:drug effects; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D012330:RNA, Double-Stranded / Q000378:metabolism*; D018749:RNA, Plant / Q000378:metabolism*; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism*; D013395:Sucrose
D003902:Detergents; D012330:RNA, Double-Stranded; D018749:RNA, Plant; D013395:Sucrose; D012324:RNA-Dependent RNA Polymerase