Analysis of nuclear RNA processing and transport by temperature perturbation of a cell-free system from mammalian cells.
The similarity of the Arrhenius plots relating temperature to messenger RNA (mRNA) transport from intact and membrane-denuded rat liver nuclei demonstrates that the ATP and cytosol-dependent transport is independent of the lipid phase of the nuclear membrane. This temperature dependence of RNA release was confirmed for alpha 2u-globulin mRNA by use of a recombinant DNA probe. Ribosomal RNA (rRNA) release showed a similar temperature dependence, suggesting that both mRNA and rRNA share a common temperature-sensitive step. The kinetics of RNA release at different temperatures suggest that RNA transport from mammalian cell nuclei is a rate-controlled rather than a graded unlocking phenomenon. The processing of mRNA precursors also exhibits a temperature dependence as shown by the linear increase in the ratio of total alpha 2u-globulin RNA to alpha 2u-globulin precursor as a function of time at 30 degrees C but not at 14 degrees C in spite of residual transport at the lower temperature. This temperature dependence of mRNA processing was confirmed by Northern blot analysis of the nuclear RNA following a 45 min incubation. Thus, both the processing and transport of RNA show temperature-sensitive steps when analyzed in cell-free systems derived from mammalian cells.
French
B T
BT
Schumm
D E
DE
Tejwani
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R
Webb
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TE
D000510:Alpha-Globulins / Q000235:genetics; D000818:Animals; D001692:Biological Transport; D002467:Cell Nucleus / Q000378:metabolism*; D002474:Cell-Free System; D003600:Cytosol / Q000378:metabolism; D004274:DNA, Recombinant; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D008297:Male; D009693:Nucleic Acid Hybridization; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013696:Temperature; D013997:Time Factors
D000510:Alpha-Globulins; D004274:DNA, Recombinant; D012333:RNA, Messenger; D012335:RNA, Ribosomal; C013803:alpha 2u globulin