scholarly journals Assembly of 5S Ribosomal RNA Is Required at a Specific Step of the Pre-rRNA Processing Pathway

1999 ◽  
Vol 145 (7) ◽  
pp. 1369-1380 ◽  
Author(s):  
Anne-Marie Dechampesme ◽  
Olga Koroleva ◽  
Isabelle Leger-Silvestre ◽  
Nicole Gas ◽  
Sylvie Camier
Keyword(s):  
Ribosomal Rna ◽  
5S Rna ◽  
Nucleolar Structure ◽  
Yeast Strains ◽  
5.8S Rrna ◽  
Specific Step ◽  
Mutant Strains ◽  
Efficient Processing ◽  
Precursor Rna ◽  
Rna Precursor

A collection of yeast strains surviving with mutant 5S RNA has been constructed. The mutant strains presented alterations of the nucleolar structure, with less granular component, and a delocalization of the 25S rRNA throughout the nucleoplasm. The 5S RNA mutations affected helix I and resulted in decreased amounts of stable 5S RNA and of the ribosomal 60S subunits. The shortage of 60S subunits was due to a specific defect in the processing of the 27SB precursor RNA that gives rise to the mature 25S and 5.8S rRNA. The processing rate of the 27SB pre-rRNA was specifically delayed, whereas the 27SA and 20S pre-rRNA were processed at a normal rate. The defect was partially corrected by increasing the amount of mutant 5S RNA. We propose that the 5S RNA is recruited by the pre-60S particle and that its recruitment is necessary for the efficient processing of the 27SB RNA precursor. Such a mechanism could ensure that all newly formed mature 60S subunits contain stoichiometric amounts of the three rRNA components.

scholarly journals METABOLISM OF RIBOSOMAL PRECURSOR RIBONUCLEIC ACID IN KIDNEY

1970 ◽  
Vol 46 (2) ◽  
pp. 362-369 ◽  
Author(s):  
Geert Ab ◽  
Ronald A. Malt
Keyword(s):  
Ribosomal Rna ◽  
Intermediate Product ◽  
Turnover Time ◽  
Mouse Kidney ◽  
Rnase Inhibitor ◽  
Phenol Extraction ◽  
Precursor Rna ◽  
Ribosomal Precursor ◽  
Kinetics Of ◽  
Rna Precursor

The labile precursors of ribosomal RNA in mouse kidney are preserved when nuclei rapidly isolated after sieving through multiple screens are swollen and cleansed in the presence of an RNase inhibitor before digestion with DNase and phenol extraction. The kinetics of nucleolar labeling analyzed on polyacrylamide gels show that 36S RNA is the major intermediate product in the catabolism of the original 45S RNA precursor to 32S RNA, from which 28S RNA is derived. Each kidney nucleus contains about 200–600 molecules of 45S RNA; the turnover time of the 45S pool is about 3 ± 2 min. Compared with HeLa cells, kidney nuclei have a different major intermediate product and a much smaller and more rapidly turning-over pool of ribosomal precursor RNA.

Synthesis of RNA in oocytes of Xenopus laevis during culture in vitro

Development ◽  
1974 ◽  
Vol 32 (2) ◽  
pp. 515-532
Author(s):  
A. Colman
Keyword(s):  
Xenopus Laevis ◽  
In Vitro Culture ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Salt Medium ◽  
Complex Media ◽  
18S Ribosomal Rna ◽  
Rna Precursor

RNA synthesis can be maintained in large oocytes of Xenopus laevis during periods of in vitro culture of at least 10 days. A simple salt medium, modified Barth's solution, is found to be as effective a culture medium for these oocytes as several other complex media. The newly synthesized RNA is characterized electrophoretically and shown to consist predominantly of ribosomal RNA precursor, 28S and 18S ribosomal RNA, and 4S RNA. The distribution of this RNA within the oocyte is detected autoradiographically, where it is found to be greatly concentrated over the nucleoli. No qualitative alterations in either of these parameters are found during culture, within the limits of sensitivity of the assay procedures.

scholarly journals The modifying enzyme Tsr3 establishes the hierarchy of Rio kinase activity in 40S ribosome assembly

2021 ◽  
Author(s):  
Haina Huang ◽  
Melissa Parker ◽  
Katrin Karbstein
Keyword(s):  
Quality Control ◽  
Binding Site ◽  
Ribosomal Rna ◽  
Ribosomal Proteins ◽  
Kinase Activity ◽  
Ribosomal Subunit ◽  
Ribosome Assembly ◽  
Small Ribosomal Subunit ◽  
Yeast Strains

AbstractRibosome assembly is an intricate process, which in eukaryotes is promoted by a large machinery comprised of over 200 assembly factors (AF) that enable the modification, folding, and processing of the ribosomal RNA (rRNA) and the binding of the 79 ribosomal proteins. While some early assembly steps occur via parallel pathways, the process overall is highly hierarchical, which allows for the integration of maturation steps with quality control processes that ensure only fully and correctly assembled subunits are released into the translating pool. How exactly this hierarchy is established, in particular given that there are many instances of RNA substrate “handover” from one highly related AF to another remains to be determined. Here we have investigated the role of Tsr3, which installs a universally conserved modification in the P-site of the small ribosomal subunit late in assembly. Our data demonstrate that Tsr3 separates the activities of the Rio kinases, Rio2 and Rio1, with whom it shares a binding site. By binding after Rio2 dissociation, Tsr3 prevents rebinding of Rio2, promoting forward assembly. After rRNA modification is complete, Tsr3 dissociates, thereby allowing for recruitment of Rio1. Inactive Tsr3 blocks Rio1, which can be rescued using mutants that bypass the requirement for Rio1 activity. Finally, yeast strains lacking Tsr3 randomize the binding of the two kinases, leading to the release of immature ribosomes into the translating pool. These data demonstrate a role for Tsr3 and its modification activity in establishing a hierarchy for the function of the Rio kinases.

scholarly journals Oocyte and somatic 5S ribosomal RNA and 5S RNA encoding genes in Xenopus tropicalis

1988 ◽  
Vol 16 (18) ◽  
pp. 8803-8815 ◽  
Author(s):  
W. Nietfeld ◽  
M. Digweed ◽  
H. Mentzel ◽  
W. Meyerhof ◽  
M. Koster ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Xenopus Tropicalis ◽  
5S Rna ◽  
5S Ribosomal Rna ◽  
Encoding Genes

scholarly journals In vitro splicing of the ribosomal RNA precursor in isolated nucleoli from Tetrahymena

1980 ◽  
Vol 8 (23) ◽  
pp. 5551-5566 ◽  
Author(s):  
M. Carin ◽  
B.F. Jensen ◽  
K.D. Jentsch ◽  
J.C. Leer ◽  
O.F. Nielsen ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
In Vitro Splicing ◽  
Rna Precursor
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