title: Polyadenylation of RNA in a cell-free system from mouse myeloma cells.
abstract: Isolated nuclei frommouse myeloma cells which were active in RNA synthesis did not synthesize detectable amounts of poly(A)-containing RNA. On addition of a soluble protein extract from crude nuclei, the highly purified nuclei synthesized significanamounts of poly(A)-containing RNA, as analyzed by chromatography on poly(U)-Sepharose. The poly(A) tract was totally synthesized de novo and was indistinguishable from poly(A) synthesized in vivo. Twenty per cent of the RNA polymerase II products were polyadenylated. More than 80% of the newly synthesized poly(A) was present on molecules at least partially transcribed in vitro. The transcription and polyadenylation reaction could be separated temporally and a portion (10%) of the polyadenylated RNA was released into the extra nuclear fraction. We conclude that this system carries out one RNA processing reaction, polyadenylation, faithfully.
mesh_terms: D000546:Amanitins / Q000494:pharmacology; D002460:Cell Line; D002474:Cell-Free System; D007700:Kinetics; D008970:Molecular Weight; D011061:Poly A / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000096:biosynthesis*; D013347:Subcellular Fractions / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000546:Amanitins; D012334:RNA, Neoplasm; D011061:Poly A