title: Biosynthesis of low molecular weight RNA in mouse myeloma cells.
abstract: The low molecular weight RNAs in the nucleus and cytoplasm of mouse myeloma cells have been characterized. There are major nuclear species (other than 5-S and tRNA), four of which contain 'capped' 5' termini. There are three major small cytoplasmic RNAs none of which contain 'caps'. The biosynthesis of the nuclear species when studied using [3H]adenosine as an RNA precursor is characterized by a rapid, transient appearance in the cytoplasm, followed by fixation in the nucleus. Within 15 min, the amount in the cytoplasm has reached a steady-state level maintained for 60 min, while the accumulation in nuclei is linear after a short lag (less than 5 min). When biosynthesis is studied using [Me-3H]methionine as a precursor, much less labeled RNA is present in the cytoplasm, suggesting that methylation may immediately precede fixation into the nucleus.
mesh_terms: D000241:Adenosine / Q000378:metabolism; D000469:Alkaline Phosphatase; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000096:biosynthesis*; D012260:Ribonucleases
chemical_list: D012313:RNA; D008715:Methionine; D012260:Ribonucleases; D000469:Alkaline Phosphatase; D000241:Adenosine