It has been shown that rat liver ribosomal proteins can be acetylated both in viuo and in vitro (Liew & Gornall, 1973). After purification of the ribosomal proteins to remove any possible contamination by lipids, nucleotides and cytoplasmic protein, the radioactivity still remained in these proteins. When the [’Hlacetate-labelled ribosomal proteins were hydrolysed in strong acid at 110°C overni...

MIany aspects of ribosomal RNA synthesis and ribosome formation in cultured animal cells have been clarified over the past several years. Ribosomal precursor RNA synthesis in the cell nucleolus' 2 is rapidly followed by methylation of the RNA.', 4 Within 20-40 minutes of synthesis this new RNA can be detected in nuclear subribosomal particles which are precursors tocytoplasmicsubribosomal parti...

Deletion of ribosomal protein L32 genes resulted in a nonsexual flocculation of fission yeast. Nonsexual flocculation also occurred when two other ribosomal protein genes, rpl21-2 and rpl9-2, were deleted. However, deletion of two nonribosomal protein genes, mpg and fbp, did not cause flocculation. Overall transcript levels of rpl32 in rpl32-1Δ and rpl32-2Δ cells were reduced by 35.9% and 46.9%...

The ribosome serves as the site of protein synthesis in all cells. Biogenesis of the mammalian ribosome is a complex process involving the coordinated expression of four ribosomal RNA molecules and approximately 75 ribosomal proteins. In order to understand the mechanisms governing ribosome biosynthesis, it is necessary to elucidate the structure and organization of its components. A cDNA clone...

NuA4 (nucleosome acetyltransferase of H4) promotes transcriptional initiation of TFIID (a complex of TBP and TBP-associated factors [TAFs])-dependent ribosomal protein genes involved in ribosome biogenesis. However, it is not clearly understood how NuA4 regulates the transcription of ribosomal protein genes. Here, we show that NuA4 is recruited to the promoters of ribosomal protein genes, such ...

The fraction and distribution of DNA complementary to ribosomal RNA and preribosomal RNA was investigated by the technique of molecular hybridization with the DNA of isolated nucleoli and nuclei of rat liver. Nuclear DNA complementary to ribosomal 18 S RNA and 28 S RNA was 0.014% and 0.032%, respectively. Nucleolar DNA complementary to ribosomal 18 S RNA and 28 S RNA was 0.10% and 0.22%, respec...

Previous work has demonstrated the capsular serotypic specificity of the protection conferred on mice by Klebsiella pneumoniae ribosomal preparations. The data in these studies support the hypothesis that capsular polysaccharide plays at least some role in the specificity of the protection conferred by ribosomal preparations. In this investigation, the presence of capsular polysaccharide and li...

The elucidation of ribosomal structure has shown that the function of ribosomes is fundamentally confined to dynamic interactions established between the RNA components of the ribosomal ensemble. These findings now enable a detailed analysis of the evolution of ribosomal RNA (rRNA) structure. The origin and diversification of rRNA was studied here using phylogenetic tools directly at the struct...

The rate-limiting step in ribosome biogenesis is the transcription of ribosomal RNA, which is controlled by environmental conditions. The JmjC enzyme KDM2A/JHDM1A/FbxL11 demethylates mono- and dimethylated Lys 36 of histone H3, but its function is unclear. Here, we show that KDM2A represses the transcription of ribosomal RNA. KDM2A was localized in nucleoli and bound to the ribosomal RNA gene p...

A secondary structure model for 16S ribosomal RNA which is based on available chemical, enzymatic, and comparative sequence data shows good agreement between constraints dictated by the model and a wide variety of experimental observations. The four major structural domains created by the base-pairing scheme correspond closely to RNA fragments isolated after nuclease digestion in the presence o...