A feedback loop coupling 5 S rRNA synthesis to accumulation of a ribosomal protein.
We have shown that elevated expression of ribosomal protein L5 in Xenopus embryos results in the ectopic activation of 5 S rRNA genes that are normally inactive. This transcriptional stimulation mimics the effect of overexpressing transcription factor IIIA (TFIIIA), the 5 S rRNA gene-specific transcription factor. The results support a model in which a network of nucleic acid-protein interactions involving 5 S rRNA, the 5 S rRNA gene, TFIIIA, and L5 mediates both feedback inhibition of 5 S rRNA synthesis and coupling of 5 S rRNA synthesis to accumulation of a ribosomal protein, L5. We propose that these mechanisms contribute to the homeostatic control of ribosome assembly.
Pittman
R H
RH
Department of Molecular Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Andrews
M T
MT
Setzer
D R
DR
D000818:Animals; D005246:Feedback; D012341:RNA, Ribosomal, 5S / Q000096:biosynthesis*; D012269:Ribosomal Proteins / Q000378:metabolism*; D014981:Xenopus
D012341:RNA, Ribosomal, 5S; D012269:Ribosomal Proteins; C029742:ribosomal protein L5