Modulation of yeast 5 S rRNA synthesis in vitro by ribosomal protein YL3. A possible regulatory loop.
Synthesis of yeast 5 S rRNA in a homologous cell-free system has previously been shown to be inhibited by exogenous yeast 5 S rRNA. This inhibition is diminished when 5 S rDNA is first incubated with the cell-free system, implying the presence of a transcription factor IIIA analog in yeast, and is dependent on the nucleotide sequence of the 5 S rRNA added. A two-dimensional gel electrophoresis method was used to demonstrate assembly of newly synthesized 5 S rRNA into a ribonucleoprotein complex containing ribosomal protein YL3. Immunodepletion of the cell-free system with anti-YL3 IgG was found to increase the sensitivity of 5 S rRNA synthesis to inhibition by 5 S rRNA. We propose a model for the regulation of yeast 5 S rRNA synthesis in which YL3 competes with the presumptive transcription factor IIIA analog for binding of 5 S rRNA.
Brow
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Department of Biology, University of California, San Diego, La Jolla 92093.
Geiduschek
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D006706:Homeostasis; D007700:Kinetics; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D012341:RNA, Ribosomal, 5S / Q000096:biosynthesis* / Q000235:genetics; D012269:Ribosomal Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S; D012269:Ribosomal Proteins