scholarly journals Depletion of yeast ribosomal proteins L16 or rp59 disrupts ribosome assembly.

1990 ◽  
Vol 111 (6) ◽  
pp. 2261-2274 ◽  
Author(s):  
M Moritz ◽  
A G Paulovich ◽  
Y F Tsay ◽  
J L Woolford
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Proteins ◽  
Ribosomal Subunit ◽  
Ribosome Assembly ◽  
Ribosomal Rnas ◽  
Subunit Protein ◽  
40S Ribosomal Subunit ◽  
Ribosomal Subunit Protein ◽  
The Stability

Two strains of Saccharomyces cerevisiae were constructed that are conditional for synthesis of the 60S ribosomal subunit protein, L16, or the 40S ribosomal subunit protein, rp59. These strains were used to determine the effects of depriving cells of either of these ribosomal proteins on ribosome assembly and on the synthesis and stability of other ribosomal proteins and ribosomal RNAs. Termination of synthesis of either protein leads to diminished accumulation of the subunit into which it normally assembles. Depletion of L16 or rp59 has no effect on synthesis of most other ribosomal proteins or ribosomal RNAs. However, most ribosomal proteins and ribosomal RNAs that are components of the same subunit as L16 or rp59 are rapidly degraded upon depletion of L16 or rp59, presumably resulting from abortive assembly of the subunit. Depletion of L16 has no effect on the stability of most components of the 40S subunit. Conversely, termination of synthesis of rp59 has no effect on the stability of most 60S subunit components. The implications of these findings for control of ribosome assembly and the order of assembly of ribosomal proteins into the ribosome are discussed.

scholarly journals Modification of yeast ribosomal proteins. Phosphorylation

1978 ◽  
Vol 175 (1) ◽  
pp. 213-219 ◽  
Author(s):  
T Kruiswijk ◽  
J T de Hey ◽  
R J Planta
Keyword(s):  
Ribosomal Proteins ◽  
Ribosomal Subunit ◽  
Electrophoretic Analysis ◽  
Ribosome Assembly ◽  
Two Dimensional ◽  
Protein Species ◽  
Phosphorylated Protein ◽  
40S Ribosomal Subunit ◽  
Phosphate Groups

Two-dimensional polyacrylamide-gel electrophoretic analysis of yeast ribosomal proteins labelled in vivo with 32PO43- revealed that the proteins S2 and S10 of the 40S ribosomal subunit, and the proteins L9, L30, L44 and L45 of the 60S ribosomal subunit, are phosphorylated in vivo. Most of the phosphate groups appeared to be linked to serine residues. Teh number of phosphate groups per molecule of phosphorylated protein species ranged from 0.01 to 0.79. Since most of the phosphorylated ribosomal proteins appear to associate with the pre-ribosomal particles at a very late stage of ribosome assembly, phosphorylation is more likely to play a role in the functioning of the ribosome than in its assembly.

Genes Encoding Ribosomal Proteins Rps0A/B of Saccharomyces cerevisiae Interact With TOM1 Mutants Defective in Ribosome Synthesis

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1107-1116
Author(s):  
Amy L Tabb ◽  
Takahiko Utsugi ◽  
Clavia R Wooten-Kee ◽  
Takeshi Sasaki ◽  
Steven A Edling ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Proteins ◽  
Elevated Temperatures ◽  
Synergistic Effects ◽  
Ribosomal Subunit ◽  
Hect Domain ◽  
Ribosome Synthesis ◽  
Ubiquitin Protein Ligase ◽  
40S Ribosomal Subunit ◽  
Genes Encoding

Abstract The Saccharomyces cerevisiae RPS0A/B genes encode proteins of the 40S ribosomal subunit that are required for the maturation of 18S rRNA. We show here that the RPS0 genes interact genetically with TOM1. TOM1 encodes a member of the hect-domain-containing E3 ubiquitin-protein ligase family that is required for growth at elevated temperatures. Mutant alleles of the RPS0 and TOM1 genes have synergistic effects on cell growth at temperatures permissive for TOM1 mutants. Moreover, the growth arrest of TOM1 mutants at elevated temperatures is partially suppressed by overexpression of RPS0A/B. Strains with mutant alleles of TOM1 are defective in multiple steps in rRNA processing, and interactions between RPS0A/B and TOM1 stem, in part, from their roles in the maturation of ribosomal subunits. Ribosome synthesis is therefore included among the cellular processes governed by members of the hect-domain-containing E3 ubiquitin-protein ligase family.

High levels of the mitochondrial large ribosomal subunit protein 40 prevent loss of mitochondrial DNA in nullmmf1 Saccharomyces cerevisiae cells

Yeast ◽  
2004 ◽  
Vol 21 (7) ◽  
pp. 539-548 ◽  
Author(s):  
Rosita Accardi ◽  
Ellinor Oxelmark ◽  
Nicolas Jauniaux ◽  
Vito de Pinto ◽  
Antonio Marchini ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Ribosomal Subunit ◽  
Large Ribosomal Subunit ◽  
Subunit Protein ◽  
Ribosomal Subunit Protein

Ribosomal protein S14 is altered by two-step emetine resistance mutations in Chinese hamster cells

1983 ◽  
Vol 3 (2) ◽  
pp. 190-197
Author(s):  
J J Madjar ◽  
M Frahm ◽  
S McGill ◽  
D J Roufa
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Ribosomal Subunit ◽  
Chinese Hamster ◽  
Complementation Group ◽  
Resistance Mutations ◽  
Cho Cell ◽  
Ribosomal Subunits ◽  
40S Ribosomal Subunit ◽  
One Step

Four two-dimensional polyacrylamide gel electrophoresis systems were used to identify 78 Chinese hamster cell ribosomal proteins by the uniform nomenclature based on rat liver ribosomal proteins. The 40S ribosomal subunit protein affected by Chinese hamster ovary (CHO) cell one-step emetine resistance mutations is designated S14 in the standard nomenclature. To seek unambiguous genetic evidence for a cause and effect relationship between CHO cell emetine resistance and mutations in the S14 gene, we mutagenized a one-step CHO cell mutant and isolated second-step mutant clones resistant to 10-fold-higher concentrations of emetine. All of the highly resistant, two-step CHO cell mutants obtained displayed additional alterations in ribosomal protein S14. Hybridization complementation tests revealed that the two-step CHO cell emetine resistance mutants were members of the same complementation group defined by one-step CHO cell mutants, EmtB. Two-step mutants obtained from a Chinese hamster lung cell emetine-resistant clone belong to the EmtA complementation group. The two-step and EmtB mutants elaborated 40S ribosomal subunits, which dissociated to 32S and 40S core particles in buffers containing 0.5 M KCl at 4 degrees C. In contrast, 40S ribosomal subunits purified from all EmtA, one-step EmtB EmtC mutants, and wild-type CHO and lung cells were stable at this temperature in buffers containing substantially higher concentrations of salt. Thus, two-step emtB mutations affect the structure of S14 protein directly and the stability of the 40S ribosomal subunit indirectly.

scholarly journals Proteotoxicity from aberrant ribosome biogenesis compromises cell fitness

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Blake W Tye ◽  
Nicoletta Commins ◽  
Lillia V Ryazanova ◽  
Martin Wühr ◽  
Michael Springer ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Ribosome Assembly ◽  
Maximal Growth ◽  
Proliferating Cells ◽  
Cellular Processes ◽  
Direct Contribution ◽  
The Face ◽  
Cellular Phenotypes

To achieve maximal growth, cells must manage a massive economy of ribosomal proteins (r-proteins) and RNAs (rRNAs) to produce thousands of ribosomes every minute. Although ribosomes are essential in all cells, natural disruptions to ribosome biogenesis lead to heterogeneous phenotypes. Here, we model these perturbations in Saccharomyces cerevisiae and show that challenges to ribosome biogenesis result in acute loss of proteostasis. Imbalances in the synthesis of r-proteins and rRNAs lead to the rapid aggregation of newly synthesized orphan r-proteins and compromise essential cellular processes, which cells alleviate by activating proteostasis genes. Exogenously bolstering the proteostasis network increases cellular fitness in the face of challenges to ribosome assembly, demonstrating the direct contribution of orphan r-proteins to cellular phenotypes. We propose that ribosome assembly is a key vulnerability of proteostasis maintenance in proliferating cells that may be compromised by diverse genetic, environmental, and xenobiotic perturbations that generate orphan r-proteins.

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 Analysis of subunit folding contribution of three yeast large ribosomal subunit proteins required for stabilisation and processing of intermediate nuclear rRNA precursors.

2021 ◽  
Author(s):  
Philipp Milkereit ◽  
Gisela Pöll ◽  
Michael Pilsl ◽  
Joachim Griesenbeck ◽  
Herbert Tschochner
Keyword(s):  
Electron Microscopy ◽  
Ribosomal Proteins ◽  
Ribosomal Subunit ◽  
Protein Assembly ◽  
Functional Coupling ◽  
Large Ribosomal Subunit ◽  
Cryo Electron Microscopy ◽  
Intrinsic Quality ◽  
Domain Arrangement ◽  
The Stability

In yeast and human cells many of the ribosomal proteins (r-proteins) are required for the stabilisation and productive processing of rRNA precursors. Functional coupling of r-protein assembly with the stabilisation and maturation of subunit precursors potentially promotes the production of ribosomes with defined composition. To further decipher mechanisms of such an intrinsic quality control pathway we analysed here the contribution of three yeast large ribosomal subunit r-proteins for intermediate nuclear subunit folding steps. Structure models obtained from single particle cryo-electron microscopy analyses provided evidence for specific and hierarchic effects on the stable positioning and remodelling of large ribosomal subunit domains. Based on these structural and previous biochemical data we discuss possible mechanisms of r-protein dependent hierarchic domain arrangement and the resulting impact on the stability of misassembled subunits.

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