The E3 SUMO ligase Mms21 controls ribosome biogenesis
Ontology highlight
ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE69826 | GEO | 2015/06/13
SECONDARY ACCESSION(S): PRJNA286877
REPOSITORIES: GEO
Similar Datasets
Project description:The budding yeast E3 SUMO ligase Mms21, a component of the Smc5-6 complex, regulates sister chromatid cohesion, DNA replication, and DNA repair. We identify a role for Mms21 in ribosome biogenesis. The mms21RINGD mutant exhibits reduced rRNA production, nuclear accumulation of 60S and 40S ribosomal proteins, and elevated Gcn4 translation. Genes involved in ribosome biogenesis and translation are down-regulated in the mms21RINGD mutant. Examining gene expression profile of mms21RINGD mutant compared to wild-type by RNA Seq using Ilumina sequencing
2015-06-13 | E-GEOD-69826 | biostudies-arrayexpress
Project description:Levels of the ribosome, the conserved molecular machine that mediates translation, are tightly linked to cellular growth rate. In humans, ribosomopathies are diseases associated with cell-type-specific pathologies and reduced ribosomal protein (RP) levels. Because gene expression defects resulting from ribosome deficiency have not yet been experimentally defined, we systematically probed mRNA, translation, and protein signatures that were either unlinked or linked to cellular growth rate in RP-deficient yeast cells. Ribosome concentration was seen to be associated with translation of gene sub-classes, and profound general secondary effects of RP loss on the spectrum of cellular mRNAs were seen. Among these effects, growth-defective 60S mutants increased synthesis of proteins involved in proteasome-mediated degradation, whereas 40S mutants accumulated mature 60S subunits and increased translation of ribosome biogenesis genes. These distinct signatures of protein synthesis suggest intriguing and currently mysterious differences in the cellular consequences of deficiency for small and large ribosomal subunits.
2018-11-29 | GSE121189 | GEO
Project description:Hcr1/eIF3j is a sub-stoichiometric subunit of eukaryotic initiation factor 3 (eIF3) that can dissociate the post-termination 40S ribosomal subunit from mRNA in vitro. We examined this ribosome recycling role in vivo by ribosome profiling and reporter assays and found that loss of Hcr1 led to reinitiation of translation in 3’UTRs, consistent with a defect in recycling. However, the defect appeared to be in recycling of the 60S subunit, rather than the 40S subunit, because reinitiation did not require an AUG codon and was suppressed by overexpression of the 60S dissociation factor Rli1/ABCE1. Consistent with a 60S recycling role, overexpression of Hcr1 could not compensate for loss of 40S recycling factors Tma64/eIF2D and Tma20/MCT-1. Intriguingly, loss of Hcr1 triggered higher expression of RLI1 via an apparent feedback loop. These findings suggest Hcr1/eIF3j is recruited to ribosomes at stop codons and may coordinate the transition to a new round of translation.
2019-05-23 | GSE124204 | GEO
Project description:The REIL proteins are required for late ribosomal biogenesis and accumulation of the 60S large ribosome subunit in mature leaves of Arabidopsis thaliana upon acclimation to low temperature. To validate these functions in roots, we conducted a multi-level system analysis targeted at understanding defects and compensations responses of reil mutants before acclimation to low temperature and following temperature shift. Hydroponic root tissue enabled analysis of eukaryotic ribosome complexes with negligible interference of organelle ribosomes. Hydroponic cultivation attenuated the growth defect of reil mutants at low temperature and provided new insights into the primary functions of Arabidopsis REIL proteins. Arabidopsis tightly controls the balance of non-translating 40S and 60S subunits. Reil mutants initially deplete both non-translating subunits upon shift to 10°C and subsequently replenish these pools slowly. Reil mutations compensate the 60S biosynthesis defect by increased baseline levels of non-translating 40S and 60S subunits and depletion of a likely non-translating, KCl-sensitive 80S sub-fraction in the cold. We infer that Arabidopsis buffers fluctuating translation demands following temperature cues by activating non-translating ribosome fractions before de novo synthesis meets temperature-induced demands. Reil1 reil2 double mutants accumulate 43S-preinitiation complexes and pre-60S-maturation complexes and affect the paralog composition of non-translating ribosome fractions. With few exceptions, e.g. RPL3B and RPL24C, these changes were not under transcriptional control. Our study suggests requirement of de novo synthesis of eukaryotic ribosomes for long-term cold acclimation. Double mutant analysis indicates feedback control of REIL-mediated 60S maturation on NUC2 and eIF3C2 transcription and implies functions of two so far non-described proteins in late plant ribosome biogenesis. We propose that Arabidopsis requires biosynthesis of specialized ribosomes for successful cold acclimation.
2021-02-03 | GSE144916 | GEO
Project description:The recycling of ribosomes at stop codons for use in further rounds of translation is critical for efficient protein synthesis. Removal of the 60S subunit is catalyzed by the ATPase Rli1 (ABCE1) while removal of the 40S is thought to require Tma64 (eIF2D), Tma20 (MCT-1), and Tma22 (DENR). However, it remains unclear how these Tma proteins cause 40S removal and control reinitiation of downstream translation. Here we developed an enhanced 40S ribosome footprinting strategy to directly observe intermediate steps of ribosome recycling in cells. Deletion of the genes encoding these Tma proteins resulted in broad accumulation of unrecycled 40S subunits at stop codons, directly establishing their role in 40S recycling. Furthermore, the Tma20/Tma22 heterodimer was responsible for a majority of 40S recycling events while Tma64 played a minor role. Introduction of an autism-associated mutation into TMA22 resulted in a loss of 40S recycling activity, linking ribosome recycling and neurological disease.
2021-03-01 | GSE145904 | GEO
Project description:eIF3 is a multi-subunit complex thought to execute numerous functions in canonical translation initiation, including mRNA recruitment to the 40S ribosome, scanning for the start codon, and inhibition of 60S subunit joining 1–3. eIF3 was also found to interact with 40S and 60S ribosomal proteins and translation elongation factors 4, but a direct involvement in translation elongation has never been demonstrated. Using selective ribosome profiling, we made the unexpected observation that eIF3 remains bound to post-initiation 80S ribosomes, followed by release after translation of ~50 codons. Furthermore, eIF3 deficiency reduces early ribosomal elongation speed, particularly on mRNAs encoding proteins associated with membrane-associated functions, resulting in defective synthesis of their encoded proteins and abnormal mitochondrial and lysosomal physiology. Accordingly, heterozygous eIF3e+/- knockout mice accumulate giant mitochondria in skeletal muscle and show a progressive decline in muscle strength with age. Hence, in addition to its canonical role in translation initiation, eIF3 interacts with 80S ribosomes to enhance, at the level of early elongation, the synthesis of proteins with membrane-associated functions, an activity that is critical for normal muscle health.
2020-06-01 | GSE131074 | GEO
Project description:eIF3 is a multi-subunit complex thought to execute numerous functions in canonical translation initiation, including mRNA recruitment to the 40S ribosome, scanning for the start codon, and inhibition of 60S subunit joining 1–3. eIF3 was also found to interact with 40S and 60S ribosomal proteins and translation elongation factors 4, but a direct involvement in translation elongation has never been demonstrated. Using selective ribosome profiling, we made the unexpected observation that eIF3 remains bound to post-initiation 80S ribosomes, followed by release after translation of ~50 codons. Furthermore, eIF3 deficiency reduces early ribosomal elongation speed, particularly on mRNAs encoding proteins associated with membrane-associated functions, resulting in defective synthesis of their encoded proteins and abnormal mitochondrial and lysosomal physiology. Accordingly, heterozygous eIF3e+/- knockout mice accumulate giant mitochondria in skeletal muscle and show a progressive decline in muscle strength with age. Hence, in addition to its canonical role in translation initiation, eIF3 interacts with 80S ribosomes to enhance, at the level of early elongation, the synthesis of proteins with membrane-associated functions, an activity that is critical for normal muscle health.
2020-06-15 | GSE149697 | GEO
Project description:Levels of the ribosome, the conserved molecular machine that mediates translation, are tightly linked to cellular growth rate. In humans, ribosomopathies are diseases associated with cell-type-specific pathologies and reduced ribosomal protein (RP) levels. Because gene expression defects resulting from ribosome deficiency have not yet been experimentally defined, we systematically probed mRNA, translation, and protein signatures that were either unlinked or linked to cellular growth rate in RP-deficient yeast cells. Ribosome concentration was seen to be associated with translation of gene sub-classes, and profound general secondary effects of RP loss on the spectrum of cellular mRNAs were seen. Among these effects, growth-defective 60S mutants increased synthesis of proteins involved in proteasome-mediated degradation, whereas 40S mutants accumulated mature 60S subunits and increased translation of ribosome biogenesis genes. These distinct signatures of protein synthesis suggest intriguing and currently mysterious differences in the cellular consequences of deficiency for small and large ribosomal subunits.
2018-10-12 | MSV000083033 | MassIVE
Project description:The recycling of ribosomal subunits after translation termination is critical for efficient gene expression. Tma64 (eIF2D), Tma20 (MCT-1), and Tma22 (DENR) function as 40S recycling factors in vitro, but it is unknown whether they perform this function in vivo or serve as alternative initiation factors. Ribosome profiling of strains missing these factors revealed 80S ribosomes queued behind the stop codon, consistent with a block in 40S recycling. We found that unrecycled ribosomes could reinitiate translation at AUG codons in the 3’UTR, as evidenced by peaks in the footprint data and 3’UTR reporter analysis. In vitro translation experiments using reporter mRNAs containing upstream ORFs (uORFs) further established that reinitiation increased in the absence of these proteins. In some cases, 40S ribosomes appeared to rejoin with 60S subunits and undergo an alternative 80S reinitiation process in 3’UTRs. These results support a crucial role for Tma64, Tma20, and Tma22 in the recycling of 40S ribosomal subunits at stop codons and translation reinitiation.
2018-08-30 | GSE108942 | GEO
Project description:In S. cerevisiae, the ribosome assembly factor Reh1 binds to pre-60S subunits at a late stage during their cytoplasmic maturation. Unlike canonical assembly factors, which associate exclusively with pre-60S subunits, we observed that Reh1 sediments with polysomes in addition to free 60S subunits. We therefore investigated the intriguing possibility that Reh1 remains associated with 60S subunits after the release of the anti-association factor Tif6 and after subunit joining. Here, we show that Reh1-bound nascent 60S subunits associate with 40S subunits to form actively translating ribosomes.
2024-01-24 | GSE246163 | GEO