Efficient NES-dependent protein nuclear export requires ongoing synthesis and export of mRNAs.
The mechanisms regulating nuclear export of proteins are not fully understood. To investigate whether the efficiency of protein nuclear export may depend on ongoing RNA synthesis and/or mRNA nuclear export, we used a microinjection approach with a fluorescent reporter protein containing a nuclear export signal (NES) and scored protein export in human fibroblasts under conditions when the synthesis or export of mRNAs was inhibited. We show that inhibition of transcription significantly attenuated generic NES-dependent nuclear export. Furthermore, digestion of endogenous nuclear RNAs by co-microinjection of RNAse A inhibited NES-dependent nuclear export. Finally, nuclear export of the NES reporter protein was significantly inhibited in cells in which nuclear export of mRNAs had been specifically blocked by microinjection of anti-TAP antibodies or by expression of a dominant negative form of NUP160. These results demonstrate a novel role for ongoing synthesis and export of mRNAs in NES-dependent protein nuclear export.
O'Hagan
Heather M
HM
Department of Radiation Oncology, University of Michigan Comprehensive Cancer Center, Ann Arbor, MI 48109, USA.
Ljungman
Mats
M
D018528:ATP-Binding Cassette Transporters; D021581:Active Transport, Cell Nucleus / Q000187:drug effects*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005456:Fluorescent Dyes; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D028884:Karyopherins / Q000378:metabolism; D008164:Luminescent Proteins; D008845:Microinjections; D008954:Models, Biological; D019913:Nuclear Localization Signals / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000187:drug effects / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins / Q000378:metabolism; D012235:Rhodamines; D012259:Ribonuclease, Pancreatic / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects; D000097606:Exportin 1 Protein
D018528:ATP-Binding Cassette Transporters; D005456:Fluorescent Dyes; D005982:Glutathione Transferase; D049452:Green Fluorescent Proteins; D015395:Histocompatibility Antigens Class I; D028884:Karyopherins; D008164:Luminescent Proteins; D019913:Nuclear Localization Signals; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D012235:Rhodamines; D012259:Ribonuclease, Pancreatic; D000097606:Exportin 1 Protein; C440251:NUP160 protein, human; C477327:transporter associated with antigen processing (TAP)