Coupled transcription and translation within nuclei of mammalian cells.
It is widely assumed that the vital processes of transcription and translation are spatially separated in eukaryotes and that no translation occurs in nuclei. We localized translation sites by incubating permeabilized mammalian cells with [3H]lysine or lysyl-transfer RNA tagged with biotin or BODIPY; although most nascent polypeptides were cytoplasmic, some were found in discrete nuclear sites known as transcription "factories." Some of this nuclear translation also depends on concurrent transcription by RNA polymerase II. This coupling is simply explained if nuclear ribosomes translate nascent transcripts as those transcripts emerge from still-engaged RNA polymerases, much as they do in bacteria.
Iborra
F J
FJ
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE UK.
Jackson
D A
DA
Cook
P R
PR
D000818:Animals; D001345:Autoradiography; D001710:Biotin / Q000378:metabolism; D001896:Boron Compounds / Q000378:metabolism; D019556:COS Cells; D002458:Cell Fractionation; D002463:Cell Membrane Permeability; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D005453:Fluorescence; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D008928:Mitochondria / Q000378:metabolism; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D011506:Proteins / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D012346:RNA, Transfer, Amino Acyl; D001710:Biotin; D003513:Cycloheximide; D012319:RNA Polymerase II