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.
Laboratory of Molecular and Cellular Biology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo, 183-8509 Japan.
H
H
Horiuchi
T
T
Udagawa
R
R
Koga
H
H
Moriyama
T
T
Fukuhara
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