title: Effect of puromycin on synthesis, processing, and nucleocytoplasmic translocation of rRNA in Tetrahymena pyriformis.
abstract: 1. Treatment of Tetrahymena pyriformis with various concentrations of puromycin results in a more pronounced inhibition of [3H]uridine accumulation in stable RNA than of protein synthesis. 2. At a concentration of 500 micrograms/ml, which is almost completely inhibitory to [3H]uridine incorporation in vivo, puromycin has no influence on the incorporation of [3H]UTP into RNA in isolated macronuclei. Pretreatment of the cells with the antibiotic, however, reduces the activity of RNA polymerases in isolated nuclei to less than 30%. 3. In puromycin-treated cells a small amount of pre-rRNA is synthesized but not processed into cytoplasmic rRNAs. 4. Puromycin reduces the nucleocytoplasmic translocation of pre-existing RNA to about 25% of the control rate within 5 min, resulting in an accumulation of relatively stable rRNA precursor molecules in the macronucleus.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D014176:Protein Biosynthesis; D011691:Puromycin / Q000494:pharmacology*; D012322:RNA Precursors / Q000187:drug effects / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects; D012335:RNA, Ribosomal / Q000187:drug effects* / Q000378:metabolism; D013769:Tetrahymena pyriformis / Q000187:drug effects* / Q000378:metabolism; D014529:Uridine / Q000378:metabolism
chemical_list: D012322:RNA Precursors; D012335:RNA, Ribosomal; D011691:Puromycin; D014529:Uridine