A role for the catalytic ribonucleoprotein RNase P in RNA polymerase III transcription.
The physical and functional links between transcription and processing machines of tRNA in the cell remain essentially unknown. We show here that whole HeLa extracts depleted of ribonuclease P (RNase P), a tRNA-processing ribonucleoprotein, exhibit a severe deficiency in RNA polymerase (Pol) III transcription of tRNA and other small, noncoding RNA genes. However, transcription can be restored by the addition of a purified holoenzyme. Targeted cleavage of the H1 RNA moiety of RNase P alters enzyme specificity and diminishes Pol III transcription. Moreover, inactivation of RNase P by targeting its protein subunits for destruction using small interfering RNAs inhibits Pol III function and Pol III-directed promoter activity in the cell. RNase P exerts its role in transcription through association with Pol III and chromatin of active tRNA and 5S rRNA genes. The results demonstrate a role for RNase P in Pol III transcription and suggest that transcription and early processing of tRNA may be coordinated.
Reiner
Robert
R
Department of Molecular Biology, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
Ben-Asouli
Yitzhak
Y
Krilovetzky
Ilana
I
Jarrous
Nayef
N
D002384:Catalysis; D002457:Cell Extracts; D002843:Chromatin / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D021122:Protein Subunits; D034622:RNA Interference; D012320:RNA Polymerase III / Q000378:metabolism*; D012341:RNA, Ribosomal, 5S / Q000235:genetics; D012343:RNA, Transfer / Q000737:chemistry; D022661:RNA, Untranslated / Q000235:genetics; D043262:Ribonuclease P / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D013379:Substrate Specificity; D014158:Transcription, Genetic
D002457:Cell Extracts; D002843:Chromatin; D021122:Protein Subunits; D012341:RNA, Ribosomal, 5S; D022661:RNA, Untranslated; D012261:Ribonucleoproteins; D012343:RNA, Transfer; D012320:RNA Polymerase III; D043262:Ribonuclease P