scholarly journals Interaction of the GTPase Elongation Factor Like-1 with the Shwachman-Diamond Syndrome Protein and Its Missense Mutations

2018 ◽  
Vol 19 (12) ◽  
pp. 4012 ◽  
Author(s):  
Abril Gijsbers ◽  
Diana Montagut ◽  
Alfonso Méndez-Godoy ◽  
Davide Altamura ◽  
Michele Saviano ◽  
...  
Keyword(s):  
Ribosomal Subunit ◽  
Interaction Mechanism ◽  
Elongation Factor ◽  
Missense Mutations ◽  
Molecular Alterations ◽  
X Ray Scattering ◽  
Genes Encoding ◽  
Initial Interaction ◽  
Shwachman Diamond Syndrome ◽  
Syndrome Protein

The Shwachman-Diamond Syndrome (SDS) is a disorder arising from mutations in the genes encoding for the Shwachman-Bodian-Diamond Syndrome (SBDS) protein and the GTPase known as Elongation Factor Like-1 (EFL1). Together, these proteins remove the anti-association factor eIF6 from the surface of the pre-60S ribosomal subunit to promote the formation of mature ribosomes. SBDS missense mutations can either destabilize the protein fold or affect surface epitopes. The molecular alterations resulting from the latter remain largely unknown, although some evidence suggest that binding to EFL1 may be affected. We further explored the effect of these SBDS mutations on the interaction with EFL1, and showed that all tested mutations disrupted the binding to EFL1. Binding was either severely weakened or almost abolished, depending on the assessed mutation. In higher eukaryotes, SBDS is essential for development, and lack of the protein results in early lethality. The existence of patients whose only source of SBDS consists of that with surface missense mutations highlights the importance of the interaction with EFL1 for their function. Additionally, we studied the interaction mechanism of the proteins in solution and demonstrated that binding consists of two independent and cooperative events, with domains 2–3 of SBDS directing the initial interaction with EFL1, followed by docking of domain 1. In solution, both proteins exhibited large flexibility and consisted of an ensemble of conformations, as demonstrated by Small Angle X-ray Scattering (SAXS) experiments.

Linking Defective Ribosome Maturation to Shwachman-Diamond Syndrome

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. SCI-36-SCI-36
Author(s):  
Alan John Warren
Keyword(s):  
Ribosome Biogenesis ◽  
Conflicts Of Interest ◽  
Ribosomal Subunit ◽  
Protein Translation ◽  
Ribosome Assembly ◽  
Genetic Dissection ◽  
Gtp Hydrolysis ◽  
Shwachman Diamond Syndrome ◽  
Novel Therapeutic Strategies ◽  
Syndrome Protein

Abstract Ribosomes are RNA-protein machines that translate the genetic information encoded by the mRNA template in all living cells. Recent high-resolution structures of the ribosome have revolutionized our understanding of protein translation. However, the mechanisms of ribosome assembly and the surveillance mechanisms that monitor this process and couple it to growth are poorly understood. Causative mutations and deletions of genes involved in ribosome biogenesis define an emerging group of disorders known as the ribosomopathies. Recent work from my laboratory strongly supports the hypothesis that Shwachman-Diamond syndrome (SDS) is a ribosomopathy caused by defective maturation of the large ribosomal subunit. Elucidation of the specific function of the SBDS protein that is deficient in SDS is revealing unexpected new insights that extend our understanding of the mechanisms underlying the late cytoplasmic steps of ribosome assembly and the quality control surveillance pathways that monitor 60S maturation. Genetic dissection of this pathway may inform novel therapeutic strategies for SDS. 1. Wong C.C., Traynor D., Basse N., Kay R.R., Warren A.J. Defective ribosome assembly in Shwachman-Diamond syndrome. Plenary Paper, Blood. 2011 Oct 20;118(16):4305-12. 2. Finch A.J., Hilcenko C., Basse N., Drynan L.F., Goyenechea B., Menne T.F., González Fernández Á., Simpson P., D’Santos C.S., Arends M.J., Donadieu J., Bellanné-Chantelot C., Costanzo M., Boone C., McKenzie A.N., Freund S.M., Warren A.J. Uncoupling of GTP hydrolysis from eIF6 release on the ribosome causes Shwachman-Diamond syndrome. Genes and Development (2011) 25: 917-929. 3. Menne T.M., Goyenechea B., Sánchez-Puig N., Wong C.C., Tonkin L.M., Ancliff P., Brost R.L., Costanzo M., Boone C. and Warren A.J. The Shwachman-Bodian-Diamond syndrome protein mediates translational activation of ribosomes in yeast. Nature Genetics (2007) 39: 486-95. Disclosures: No relevant conflicts of interest to declare.

scholarly journals EFL1 mutations impair eIF6 release to cause Shwachman-Diamond syndrome

Blood ◽  
2019 ◽  
Vol 134 (3) ◽  
pp. 277-290 ◽  
Author(s):  
Shengjiang Tan ◽  
Laëtitia Kermasson ◽  
Angela Hoslin ◽  
Pekka Jaako ◽  
Alexandre Faille ◽  
...  
Keyword(s):  
Hematological Malignancies ◽  
Bone Marrow Failure ◽  
Ribosomal Subunit ◽  
Elongation Factor ◽  
Protein Translation ◽  
Allosteric Regulator ◽  
Shwachman Diamond Syndrome ◽  
Biallelic Mutations ◽  
Key Aspects ◽  
Subunit Joining

Abstract Shwachman-Diamond syndrome (SDS) is a recessive disorder typified by bone marrow failure and predisposition to hematological malignancies. SDS is predominantly caused by deficiency of the allosteric regulator Shwachman-Bodian-Diamond syndrome that cooperates with elongation factor-like GTPase 1 (EFL1) to catalyze release of the ribosome antiassociation factor eIF6 and activate translation. Here, we report biallelic mutations in EFL1 in 3 unrelated individuals with clinical features of SDS. Cellular defects in these individuals include impaired ribosomal subunit joining and attenuated global protein translation as a consequence of defective eIF6 eviction. In mice, Efl1 deficiency recapitulates key aspects of the SDS phenotype. By identifying biallelic EFL1 mutations in SDS, we define this leukemia predisposition disorder as a ribosomopathy that is caused by corruption of a fundamental, conserved mechanism, which licenses entry of the large ribosomal subunit into translation.

scholarly journals On the Need to Tell Apart Fraternal Twins eEF1A1 and eEF1A2, and Their Respective Outfits

2021 ◽  
Vol 22 (13) ◽  
pp. 6973
Author(s):  
Alberto Mills ◽  
Federico Gago
Keyword(s):  
De Novo ◽  
Elongation Factor ◽  
Missense Mutations ◽  
Developmentally Regulated ◽  
High Sequence Identity ◽  
80S Ribosome ◽  
Cellular Effects ◽  
Cellular Processes ◽  
Eukaryotic Elongation Factor ◽  
A Site

eEF1A1 and eEF1A2 are paralogous proteins whose presence in most normal eukaryotic cells is mutually exclusive and developmentally regulated. Often described in the scientific literature under the collective name eEF1A, which stands for eukaryotic elongation factor 1A, their best known activity (in a monomeric, GTP-bound conformation) is to bind aminoacyl-tRNAs and deliver them to the A-site of the 80S ribosome. However, both eEF1A1 and eEF1A2 are endowed with multitasking abilities (sometimes performed by homo- and heterodimers) and can be located in different subcellular compartments, from the plasma membrane to the nucleus. Given the high sequence identity of these two sister proteins and the large number of post-translational modifications they can undergo, we are often confronted with the dilemma of discerning which is the particular proteoform that is actually responsible for the ascribed biochemical or cellular effects. We argue in this review that acquiring this knowledge is essential to help clarify, in molecular and structural terms, the mechanistic involvement of these two ancestral and abundant G proteins in a variety of fundamental cellular processes other than translation elongation. Of particular importance for this special issue is the fact that several de novo heterozygous missense mutations in the human EEF1A2 gene are associated with a subset of rare but severe neurological syndromes and cardiomyopathies.

scholarly journals Genetic Analysis of Colistin Resistance in Salmonella enterica Serovar Typhimurium

2009 ◽  
Vol 53 (6) ◽  
pp. 2298-2305 ◽  
Author(s):  
Song Sun ◽  
Aurel Negrea ◽  
Mikael Rhen ◽  
Dan I. Andersson
Keyword(s):  
Mutation Rate ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Regulatory System ◽  
Clinical Settings ◽  
Missense Mutations ◽  
Regulator Protein ◽  
Serovar Typhimurium ◽  
Sensor Kinases ◽  
Genes Encoding

ABSTRACT Colistin is a cyclic cationic peptide that kills gram-negative bacteria by interacting with and disrupting the outer membrane. We isolated 44 independent mutants in Salmonella enterica serovar Typhimurium with reduced susceptibility to colistin and identified 27 different missense mutations located in the pmrA and pmrB genes (encoding the regulator and sensor of a two-component regulatory system) that conferred increased resistance. By comparison of the two homologous sensor kinases, PmrB and EnvZ, the 22 missense mutations identified in pmrB were shown to be located in four different structural domains of the protein. All five pmrA mutations were located in the phosphate receiver domain of the regulator protein. The mutants appeared at a mutation rate of 0.6 × 10−6 per cell per generation. The MICs of colistin for the mutants increased 2- to 35-fold, and the extent of killing was reduced several orders of magnitude compared to the susceptible strain. The growth rates of the mutants were slightly reduced in both rich medium and M9-glycerol minimal medium, whereas growth in mice appeared unaffected by the pmrA and pmrB mutations. The low fitness costs and the high mutation rate suggest that mutants with reduced susceptibility to colistin could emerge in clinical settings.

Elongation factor EF-1 alpha gene dosage alters translational fidelity in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (10) ◽  
pp. 4571-4575
Author(s):  
J M Song ◽  
S Picologlou ◽  
C M Grant ◽  
M Firoozan ◽  
M F Tuite ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Dosage ◽  
Elongation Factor ◽  
Nonsense Suppression ◽  
Translational Fidelity ◽  
Genes Encoding ◽  
Alpha Gene ◽  
Nonsense Codons

Changes in the dosage of genes encoding elongation factor EF-1 alpha were shown to cause parallel changes in the misreading of nonsense codons. Higher amounts of EF-1 alpha were correlated with increased nonsense suppression, suggesting that the level of EF-1 alpha is critically involved in translational fidelity.

scholarly journals A Budding Yeast Model for Human Disease Mutations in the EXOSC2 Cap Subunit of the RNA Exosome

2020 ◽  
Author(s):  
Maria C. Sterrett ◽  
Liz Enyenihi ◽  
Sara W. Leung ◽  
Laurie Hess ◽  
Sarah E. Strassler ◽  
...  
Keyword(s):  
Amino Acid ◽  
Budding Yeast ◽  
Amino Acid Substitutions ◽  
Missense Mutations ◽  
Subunit Gene ◽  
Rna Targets ◽  
Genes Encoding ◽  
Rna Exosome ◽  
Transcriptomic Changes

AbstractRNA exosomopathies, a growing family of tissue-specific diseases, are linked to missense mutations in genes encoding the structural subunits of the conserved 10-subunit exoribonuclease complex, the RNA exosome. Such mutations in the cap subunit gene EXOSC2 cause the novel syndrome SHRF (Short stature, Hearing loss, Retinitis pigmentosa and distinctive Facies). In contrast, exosomopathy mutations in the cap subunit gene EXOSC3 cause pontocerebellar hypoplasia type 1b (PCH1b). Though having strikingly different disease pathologies, EXOSC2 and EXOSC3 exosomopathy mutations result in amino acid substitutions in similar, conserved domains of the cap subunits, suggesting that these exosomopathy mutations have distinct consequences for RNA exosome function. We generated the first in vivo model of the SHRF pathogenic amino acid substitutions using budding yeast by introducing the EXOSC2 mutations in the orthologous S. cerevisiae gene RRP4. The resulting rrp4 mutant cells have defects in cell growth and RNA exosome function. We detect significant transcriptomic changes in both coding and non-coding RNAs in the rrp4 variant, rrp4-G226D, which models EXOSC2 p.Gly198Asp. Comparing this rrp4-G226D mutant to the previously studied S. cerevisiae model of EXOSC3 PCH1b mutation, rrp40-W195R, reveals that these mutants have disparate effects on certain RNA targets, providing the first evidence for different mechanistic consequences of these exosomopathy mutations. Congruently, we detect specific negative genetic interactions between RNA exosome cofactor mutants and rrp4-G226D but not rrp40-W195R. These data provide insight into how SHRF mutations could alter the function of the RNA exosome and allow the first direct comparison of exosomopathy mutations that cause distinct pathologies.

The ribosome as a molecular machine: the mechanism of tRNA–mRNA movement in translocation

2011 ◽  
Vol 39 (2) ◽  
pp. 658-662 ◽  
Author(s):  
Marina V. Rodnina ◽  
Wolfgang Wintermeyer
Keyword(s):  
Ribosomal Subunit ◽  
Elongation Factor ◽  
Thermal Fluctuations ◽  
Spontaneous Movement ◽  
Conformational States ◽  
Gtp Hydrolysis ◽  
Time Resolved ◽  
Directional Bias ◽  
Loosely Coupled ◽  
Dynamic Events

Translocation of tRNA and mRNA through the ribosome is one of the most dynamic events during protein synthesis. In the cell, translocation is catalysed by EF-G (elongation factor G) and driven by GTP hydrolysis. Major unresolved questions are: how the movement is induced and what the moving parts of the ribosome are. Recent progress in time-resolved cryoelectron microscopy revealed trajectories of tRNA movement through the ribosome. Driven by thermal fluctuations, the ribosome spontaneously samples a large number of conformational states. The spontaneous movement of tRNAs through the ribosome is loosely coupled to the motions within the ribosome. EF-G stabilizes conformational states prone to translocation and promotes a conformational rearrangement of the ribosome (unlocking) that accelerates the rate-limiting step of translocation: the movement of the tRNA anticodons on the small ribosomal subunit. EF-G acts as a Brownian ratchet providing directional bias for movement at the cost of GTP hydrolysis.

Effects of SEL-12 presenilin on LIN-12 localization and function in Caenorhabditis elegans

Development ◽  
1998 ◽  
Vol 125 (18) ◽  
pp. 3599-3606 ◽  
Author(s):  
D. Levitan ◽  
I. Greenwald
Keyword(s):  
Plasma Membranes ◽  
General Factor ◽  
Missense Mutations ◽  
Protein Activity ◽  
App Processing ◽  
Notch Activity ◽  
C Elegans ◽  
Vulval Precursor Cells ◽  
Genes Encoding ◽  
And Function

Presenilins have been implicated in the development of Alzheimer's disease and in facilitating LIN-12/Notch activity. Here, we use genetic methods to explore the relationship between C. elegans LIN-12 and SEL-12 presenilin. Reducing sel-12 activity can suppress the effects of elevated lin-12 activity when LIN-12 is activated by missense mutations but not when LIN-12 is activated by removal of the extracellular and transmembrane domains. These results suggest that SEL-12 does not function downstream of activated LIN-12. An active SEL-12::GFP hybrid protein accumulates in the perinuclear region of the vulval precursor cells (VPCs) of living hermaphrodites, consistent with a localization in endoplasmic reticulum/Golgi membranes; when sel-12 activity is reduced, less LIN-12 protein accumulates in the plasma membranes of the VPCs. Together with the genetic interactions between lin-12 and sel-12, these observations suggest a role for SEL-12 in LIN-12 processing or trafficking. However, SEL-12 does not appear to be a general factor that influences membrane protein activity, since reducing sel-12 activity does not suppress or enhance hypomorphic mutations in other genes encoding membrane proteins. We discuss potential parallels for the role of SEL-12/presenilin in facilitating LIN-12/Notch activity and in amyloid precursor protein (APP) processing.

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