title: Comparison of cytoplasmic and nuclear poly(A)-containing RNA sequences in Xenopus liver cells.
abstract: Poly(A)-containing RNAs from cytoplasm and nuclei of adult Xenopus liver cells are compared. After denaturation of the RNA by dimethysulfoxide the average molecule of nuclear poly(A)-containing RNA has a sedimentation value of 28 S whereas the cytoplasmic poly(A)-containing RNA sediments slightly ahead of 18 S. To compare the complexity of cytoplasmic and nuclear poly(A)-containing RNA, complementary DNA (cDNA) transcribed on either cytoplasmic or nuclear RNA is hybridized to the RNA used as a template. The hybridization kinetics suggest a higher complexity of the nuclear RNA compared to the cytoplasmic fraction. Direct evidence of a higher complexity of nuclear poly(A)-containing RNA is shown by the fact that 30% of the nuclear cDNA fails to hybridize with cytoplasmic poly(A)-containing RNA. An attempt to isolate a specific probe for this nucleus-restricted poly(A)-containing RNA reveals that more than 10(4) different nuclear RNA sequences adjacent to the poly(A) do not get into the cytoplasm. We conclude that a poly(A) on a nuclear RNA does not ensure the transport of the adjacent sequence to the cytoplasm.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000032:analysis*; D007700:Kinetics; D008099:Liver / Q000032:analysis*; D008297:Male; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D009695:Nucleic Acid Renaturation; D011061:Poly A / Q000032:analysis*; D012313:RNA; D014981:Xenopus
chemical_list: D011061:Poly A; D012313:RNA