Eukaryotic protein uS19: a component of the decoding site of ribosomes and a player in human diseases

2021 ◽  
Vol 478 (5) ◽  
pp. 997-1008
Author(s):  
Dmitri Graifer ◽  
Galina Karpova
Keyword(s):  
Ribosome Biogenesis ◽  
Lymphocytic Leukemia ◽  
Human Diseases ◽  
Tumor Suppressor P53 ◽  
Translational Fidelity ◽  
Gene Encoding ◽  
Ribosomal Subunits ◽  
Translational Machinery ◽  
Diamond Blackfan Anemia ◽  
Ribosomal Function

Proteins belonging to the universal ribosomal protein (rp) uS19 family are constituents of small ribosomal subunits, and their conserved globular parts are involved in the formation of the head of these subunits. The eukaryotic rp uS19 (previously known as S15) comprises a C-terminal extension that has no homology in the bacterial counterparts. This extension is directly implicated in the formation of the ribosomal decoding site and thereby affects translational fidelity in a manner that has no analogy in bacterial ribosomes. Another eukaryote-specific feature of rp uS19 is its essential participance in the 40S subunit maturation due to the interactions with the subunit assembly factors required for the nuclear exit of pre-40S particles. Beyond properties related to the translation machinery, eukaryotic rp uS19 has an extra-ribosomal function concerned with its direct involvement in the regulation of the activity of an important tumor suppressor p53 in the Mdm2/Mdmx-p53 pathway. Mutations in the RPS15 gene encoding rp uS19 are linked to diseases (Diamond Blackfan anemia, chronic lymphocytic leukemia and Parkinson's disease) caused either by defects in the ribosome biogenesis or disturbances in the functioning of ribosomes containing mutant rp uS19, likely due to the changed translational fidelity. Here, we review currently available data on the involvement of rp uS19 in the operation of the translational machinery and in the maturation of 40S subunits, on its extra-ribosomal function, and on relationships between mutations in the RPS15 gene and certain human diseases.

scholarly journals Impaired ribosome biogenesis in Diamond-Blackfan anemia

Blood ◽  
2006 ◽  
Vol 109 (3) ◽  
pp. 1275-1283 ◽  
Author(s):  
Valérie Choesmel ◽  
Daniel Bacqueville ◽  
Jacques Rouquette ◽  
Jacqueline Noaillac-Depeyre ◽  
Sébastien Fribourg ◽  
...  
Keyword(s):  
Ribosome Biogenesis ◽  
18S Rrna ◽  
Ribosomal Subunit ◽  
Rrna Synthesis ◽  
Rrna Processing ◽  
Gene Encoding ◽  
Ribosomal Subunits ◽  
Diamond Blackfan Anemia ◽  
Nucleolar Organization ◽  
Ribosomal Protein S19

Abstract The gene encoding the ribosomal protein S19 (RPS19) is frequently mutated in Diamond-Blackfan anemia (DBA), a congenital erythroblastopenia. The consequence of these mutations on the onset of the disease remains obscure. Here, we show that RPS19 plays an essential role in biogenesis of the 40S small ribosomal subunit in human cells. Knockdown of RPS19 expression by siRNAs impairs 18S rRNA synthesis and formation of 40S subunits and induces apoptosis in HeLa cells. Pre-rRNA processing is altered, which leads to an arrest in the maturation of precursors to the 18S rRNA. Under these conditions, pre-40S particles are not exported to the cytoplasm and accumulate in the nucleoplasm of the cells in perinuclear dots. Consistently, we find that ribosome biogenesis and nucleolar organization is altered in skin fibroblasts from DBA patients bearing mutations in the RPS19 gene. In addition, maturation of the 18S rRNA is also perturbed in cells from a patient bearing no RPS19-related mutation. These results support the hypothesis that DBA is directly related to a defect in ribosome biogenesis and indicate that yet to be discovered DBA-related genes may be involved in the synthesis of the ribosomal subunits.

scholarly journals Altered patterns of global protein synthesis and translational fidelity in RPS15-mutated chronic lymphocytic leukemia

Blood ◽  
2018 ◽  
Vol 132 (22) ◽  
pp. 2375-2388 ◽  
Author(s):  
Gabriel Bretones ◽  
Miguel G. Álvarez ◽  
Javier R. Arango ◽  
David Rodríguez ◽  
Ferran Nadeu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Chronic Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Driver Gene ◽  
Translational Fidelity ◽  
Translational Machinery ◽  
Global Protein Synthesis ◽  
Proteome Level ◽  
Genomic Studies ◽  
Altered Cell

Abstract Genomic studies have recently identified RPS15 as a new driver gene in aggressive and chemorefractory cases of chronic lymphocytic leukemia (CLL). RPS15 encodes a ribosomal protein whose conserved C-terminal domain extends into the decoding center of the ribosome. We demonstrate that mutations in highly conserved residues of this domain affect protein stability, by increasing its ubiquitin-mediated degradation, and cell-proliferation rates. On the other hand, we show that mutated RPS15 can be loaded into the ribosomes, directly impacting on global protein synthesis and/or translational fidelity in a mutation-specific manner. Quantitative mass spectrometry analyses suggest that RPS15 variants may induce additional alterations in the translational machinery, as well as a metabolic shift at the proteome level in HEK293T and MEC-1 cells. These results indicate that CLL-related RPS15 mutations might act following patterns known for other ribosomal diseases, likely switching from a hypo- to a hyperproliferative phenotype driven by mutated ribosomes. In this scenario, loss of translational fidelity causing altered cell proteostasis can be proposed as a new molecular mechanism involved in CLL pathobiology.

scholarly journals Characterization of Saccharomyces cerevisiae strains displaying high-level or low-level resistance to trichothecene antibiotics

1990 ◽  
Vol 267 (3) ◽  
pp. 709-713 ◽  
Author(s):  
M Fernandez-Lobato ◽  
M Cannon ◽  
J A Mitlin ◽  
R C Mount ◽  
A Jimenez
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosome Biogenesis ◽  
Gene Encoding ◽  
Ribosomal Subunits ◽  
Low Level ◽  
Ribosomal Protein L3 ◽  
High Level ◽  
Level Resistance

Biochemical and genetic analyses have been carried out on Saccharomyces cerevisiae strains characterized in vivo as sensitive, low-level-resistant or high-level-resistant to trichothecene antibiotics. Levels of drug resistance in vitro were determined for each strain and for suitable diploids derived from them. Ribosome biogenesis was also studied in selected haploids. It is suggested that resistance in all cases results from a mutation in the gene encoding ribosomal protein L3. If this is indeed the situation, then different mutations in this same gene not only can cause low-level or high-level resistance to trichothecene antibiotics but also can affect the maturation of either 40 S or 60 S ribosomal subunits.

scholarly journals Nucleolar Organization and Functions in Health and Disease

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 526 ◽  
Author(s):  
Ursula Stochaj ◽  
Stephanie C. Weber
Keyword(s):  
Stress Responses ◽  
Ribosome Biogenesis ◽  
Molecular Mechanisms ◽  
Rrna Genes ◽  
Cell Physiology ◽  
Ribosomal Subunits ◽  
Diamond Blackfan Anemia ◽  
Health And Disease ◽  
Progeria Syndrome ◽  
Hutchinson Gilford Progeria Syndrome

The nucleolus is a prominent, membraneless compartment found within the nucleus of eukaryotic cells. It forms around ribosomal RNA (rRNA) genes, where it coordinates the transcription, processing, and packaging of rRNA to produce ribosomal subunits. Recent efforts to characterize the biophysical properties of the nucleolus have transformed our understanding of the assembly and organization of this dynamic compartment. Indeed, soluble macromolecules condense from the nucleoplasm to form nucleoli through a process called liquid–liquid phase separation. Individual nucleolar components rapidly exchange with the nucleoplasm and separate within the nucleolus itself to form distinct subcompartments. In addition to its essential role in ribosome biogenesis, the nucleolus regulates many aspects of cell physiology, including genome organization, stress responses, senescence and lifespan. Consequently, the nucleolus is implicated in several human diseases, such as Hutchinson–Gilford progeria syndrome, Diamond–Blackfan anemia, and various forms of cancer. This Special Issue highlights new insights into the physical and molecular mechanisms that control the architecture and diverse functions of the nucleolus, and how they break down in disease.

scholarly journals The Putative RNA Helicase Dbp6p Functionally Interacts With Rpl3p, Nop8p and the Novel trans-acting Factor Rsa3p During Biogenesis of 60S Ribosomal Subunits in Saccharomyces cerevisiae

Genetics ◽  
2004 ◽  
Vol 166 (4) ◽  
pp. 1687-1699
Author(s):  
Jesús de la Cruz ◽  
Thierry Lacombe ◽  
Olivier Deloche ◽  
Patrick Linder ◽  
Dieter Kressler
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosome Biogenesis ◽  
Null Allele ◽  
Ribosomal Subunit ◽  
Interaction Network ◽  
The Novel ◽  
Rna Helicases ◽  
Ribosomal Subunits ◽  
Synthetic Lethal ◽  
Synthetically Lethal

Abstract Ribosome biogenesis requires at least 18 putative ATP-dependent RNA helicases in Saccharomyces cerevisiae. To explore the functional environment of one of these putative RNA helicases, Dbp6p, we have performed a synthetic lethal screen with dbp6 alleles. We have previously characterized the nonessential Rsa1p, whose null allele is synthetically lethal with dbp6 alleles. Here, we report on the characterization of the four remaining synthetic lethal mutants, which reveals that Dbp6p also functionally interacts with Rpl3p, Nop8p, and the so-far-uncharacterized Rsa3p (ribosome assembly 3). The nonessential Rsa3p is a predominantly nucleolar protein required for optimal biogenesis of 60S ribosomal subunits. Both Dbp6p and Rsa3p are associated with complexes that most likely correspond to early pre-60S ribosomal particles. Moreover, Rsa3p is co-immunoprecipitated with protA-tagged Dbp6p under low salt conditions. In addition, we have established a synthetic interaction network among factors involved in different aspects of 60S-ribosomal-subunit biogenesis. This extensive genetic analysis reveals that the rsa3 null mutant displays some specificity by being synthetically lethal with dbp6 alleles and by showing some synthetic enhancement with the nop8-101 and the rsa1 null allele.

Control points in eucaryotic ribosome biogenesis

1991 ◽  
Vol 69 (1) ◽  
pp. 5-22 ◽  
Author(s):  
D. E. Larson ◽  
P. Zahradka ◽  
B. H. Sells
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Rna Polymerase Iii ◽  
Ribosomal Subunits ◽  
Rrna Species ◽  
Polymerase I ◽  
Ribosomal Precursor ◽  
Precursor Molecules

Ribosome biogenesis in eucaryotic cells involves the coordinated synthesis of four rRNA species, transcribed by RNA polymerase I (18S, 28S, 5.8S) and RNA polymerase III (5S), and approximately 80 ribosomal proteins translated from mRNAs synthesized by RNA polymerase II. Assembly of the ribosomal subunits in the nucleolus, the site of 45S rRNA precursor gene transcription, requires the movement of 5S rRNA and ribosomal proteins from the nucleoplasm and cytoplasm, respectively, to this structure. To integrate these events and ensure the balanced production of individual ribosomal components, different strategies have been developed by eucaryotic organisms in response to a variety of physiological changes. This review presents an overview of the mechanisms modulating the production of ribosomal precursor molecules and the rate of ribosome biogenesis in various biological systems.Key words: rRNA, ribosomal proteins, nucleolus, ribosome.

Yeast ribosomal protein L1 is required for the stability of newly synthesized 5S rRNA and the assembly of 60S ribosomal subunits

1993 ◽  
Vol 13 (5) ◽  
pp. 2835-2845
Author(s):  
M Deshmukh ◽  
Y F Tsay ◽  
A G Paulovich ◽  
J L Woolford
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Subunit ◽  
Single Copy ◽  
5S Rrna ◽  
Gene Encoding ◽  
Ribosomal Subunits ◽  
Ribosomal Protein L1 ◽  
The Stability ◽  
And Function

Ribosomal protein L1 from Saccharomyces cerevisiae binds 5S rRNA and can be released from intact 60S ribosomal subunits as an L1-5S ribonucleoprotein (RNP) particle. To understand the nature of the interaction between L1 and 5S rRNA and to assess the role of L1 in ribosome assembly and function, we cloned the RPL1 gene encoding L1. We have shown that RPL1 is an essential single-copy gene. A conditional null mutant in which the only copy of RPL1 is under control of the repressible GAL1 promoter was constructed. Depletion of L1 causes instability of newly synthesized 5S rRNA in vivo. Cells depleted of L1 no longer assemble 60S ribosomal subunits, indicating that L1 is required for assembly of stable 60S ribosomal subunits but not 40S ribosomal subunits. An L1-5S RNP particle not associated with ribosomal particles was detected by coimmunoprecipitation of L1 and 5S rRNA. This pool of L1-5S RNP remained stable even upon cessation of 60S ribosomal subunit assembly by depletion of another ribosomal protein, L16. Preliminary results suggest that transcription of RPL1 is not autogenously regulated by L1.

scholarly journals Neuronal ribosomes exhibit dynamic and context-dependent exchange of ribosomal proteins

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Claudia M. Fusco ◽  
Kristina Desch ◽  
Aline R. Dörrbaum ◽  
Mantian Wang ◽  
Anja Staab ◽  
...  
Keyword(s):  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Ribosome Profiling ◽  
Metabolic Labeling ◽  
Local Protein Synthesis ◽  
Translational Machinery ◽  
Neuronal Synapses ◽  
Cellular Environment ◽  
Neuronal Processes ◽  
Local Protein

AbstractOwing to their morphological complexity and dense network connections, neurons modify their proteomes locally, using mRNAs and ribosomes present in the neuropil (tissue enriched for dendrites and axons). Although ribosome biogenesis largely takes place in the nucleus and perinuclear region, neuronal ribosomal protein (RP) mRNAs have been frequently detected remotely, in dendrites and axons. Here, using imaging and ribosome profiling, we directly detected the RP mRNAs and their translation in the neuropil. Combining brief metabolic labeling with mass spectrometry, we found that a group of RPs rapidly associated with translating ribosomes in the cytoplasm and that this incorporation was independent of canonical ribosome biogenesis. Moreover, the incorporation probability of some RPs was regulated by location (neurites vs. cell bodies) and changes in the cellular environment (following oxidative stress). Our results suggest new mechanisms for the local activation, repair and/or specialization of the translational machinery within neuronal processes, potentially allowing neuronal synapses a rapid means to regulate local protein synthesis.

scholarly journals The Nuclear Export Receptors TbMex67 and TbMtr2 Are Required for Ribosome Biogenesis in Trypanosoma brucei

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Constance Rink ◽  
Martin Ciganda ◽  
Noreen Williams
Keyword(s):  
Trypanosoma Brucei ◽  
Nuclear Export ◽  
Ribosome Biogenesis ◽  
Biological Process ◽  
Large Subunit ◽  
Critical Role ◽  
Ribosomal Subunits ◽  
Content Type ◽  
Protein Components ◽  
Export Receptors

ABSTRACT Ribosomal maturation is a complex and highly conserved biological process involving migration of a continuously changing RNP across multiple cellular compartments. A critical point in this process is the translocation of individual ribosomal subunits (60S and 40S) from the nucleus to the cytoplasm, and a number of export factors participate in this process. In this study, we characterize the functional role of the auxiliary export receptors TbMex67 and TbMtr2 in ribosome biogenesis in the parasite Trypanosoma brucei. We demonstrate that depletion of each of these proteins dramatically impacts the steady-state levels of other proteins involved in ribosome biogenesis, including the trypanosome-specific factors P34 and P37. In addition, we observe that the loss of TbMex67 or TbMtr2 leads to aberrant ribosome formation, rRNA processing, and polysome formation. Although the TbMex67-TbMtr2 heterodimer is structurally distinct from Mex67-Mtr2 complexes previously studied, our data show that they retain a conserved function in ribosome biogenesis. IMPORTANCE The nuclear export of ribosomal subunits (60S and 40S) depends in part on the activity of the essential auxiliary export receptors TbMtr2 and TbMex67. When these proteins are individually depleted from the medically and agriculturally significant parasite Trypanosoma brucei, distinct alterations in the processing of the rRNAs of the large subunit (60S) are observed as well as aberrations in the assembly of functional ribosomes (polysomes). We also established that TbMex67 and TbMtr2 interact directly or indirectly with the protein components of the 5S RNP, including the trypanosome-specific P34/P37. The critical role that TbMex67 and TbMtr2 play in this essential biological process together with their parasite-specific interactions may provide new therapeutic targets against this important parasite.

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