Isolation of Cytosolic Ribosomes

2016 ◽  
pp. 241-247
Author(s):  
Hanna Klang Årstrand ◽  
Maria V. Turkina
Keyword(s):  
Cytosolic Ribosomes

scholarly journals Proteomic Characterization of Evolutionarily Conserved and Variable Proteins of Arabidopsis Cytosolic Ribosomes

2005 ◽  
Vol 137 (3) ◽  
pp. 848-862 ◽  
Author(s):  
Ing-Feng Chang ◽  
Kathleen Szick-Miranda ◽  
Songqin Pan ◽  
Julia Bailey-Serres
Keyword(s):  
Evolutionarily Conserved ◽  
Cytosolic Ribosomes

scholarly journals Formyl-methionine as an N-degron of a eukaryotic N-end rule pathway

Science ◽  
2018 ◽  
Vol 362 (6418) ◽  
pp. eaat0174 ◽  
Author(s):  
Jeong-Mok Kim ◽  
Ok-Hee Seok ◽  
Shinyeong Ju ◽  
Ji-Eun Heo ◽  
Jeonghun Yeom ◽  
...  
Keyword(s):  
Amino Acids ◽  
Stationary Phase ◽  
Ubiquitin Ligase ◽  
Bacterial Proteins ◽  
Cytosolic Ribosomes

In bacteria, nascent proteins bear the pretranslationally generated N-terminal (Nt) formyl-methionine (fMet) residue. Nt-fMet of bacterial proteins is a degradation signal, termed fMet/N-degron. By contrast, proteins synthesized by cytosolic ribosomes of eukaryotes were presumed to bear unformylated Nt-Met. Here we found that the yeast formyltransferase Fmt1, although imported into mitochondria, could also produce Nt-formylated proteins in the cytosol. Nt-formylated proteins were strongly up-regulated in stationary phase or upon starvation for specific amino acids. This up-regulation strictly required the Gcn2 kinase, which phosphorylates Fmt1 and mediates its retention in the cytosol. We also found that the Nt-fMet residues of Nt-formylated proteins act as fMet/N-degrons and identified the Psh1 ubiquitin ligase as the recognition component of the eukaryotic fMet/N-end rule pathway, which destroys Nt-formylated proteins.

scholarly journals Visualization of cytosolic ribosomes on the surface of mitochondria by electron cryo‐tomography

EMBO Reports ◽  
2017 ◽  
Vol 18 (10) ◽  
pp. 1786-1800 ◽  
Author(s):  
Vicki AM Gold ◽  
Piotr Chroscicki ◽  
Piotr Bragoszewski ◽  
Agnieszka Chacinska
Keyword(s):  
Cytosolic Ribosomes

scholarly journals Erratum: Corrigendum: OM14 is a mitochondrial receptor for cytosolic ribosomes that supports co-translational import into mitochondria

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Chen Lesnik ◽  
Yifat Cohen ◽  
Avigail Atir-Lande ◽  
Maya Schuldiner ◽  
Yoav Arava
Keyword(s):  
Cytosolic Ribosomes

scholarly journals OM14 is a mitochondrial receptor for cytosolic ribosomes that supports co-translational import into mitochondria

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Chen Lesnik ◽  
Yifat Cohen ◽  
Avigail Atir-Lande ◽  
Maya Schuldiner ◽  
Yoav Arava
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Strong Support ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Import ◽  
Translational Mode ◽  
Nascent Chain ◽  
Cytosolic Ribosomes

Abstract It is well established that import of proteins into mitochondria can occur after their complete synthesis by cytosolic ribosomes. Recently, an additional model was revived, proposing that some proteins are imported co-translationally. This model entails association of ribosomes with the mitochondrial outer membrane, shown to be mediated through the ribosome-associated chaperone nascent chain-associated complex (NAC). However, the mitochondrial receptor of this complex is unknown. Here, we identify the Saccharomyces cerevisiae outer membrane protein OM14 as a receptor for NAC. OM14Δ mitochondria have significantly lower amounts of associated NAC and ribosomes, and ribosomes from NAC[Δ] cells have reduced levels of associated OM14. Importantly, mitochondrial import assays reveal a significant decrease in import efficiency into OM14Δ mitochondria, and OM14-dependent import necessitates NAC. Our results identify OM14 as the first mitochondrial receptor for ribosome-associated NAC and reveal its importance for import. These results provide a strong support for an additional, co-translational mode of import into mitochondria.

scholarly journals The ribosome quality control pathway can access nascent polypeptides stalled at the Sec61 translocon

2015 ◽  
Vol 26 (12) ◽  
pp. 2168-2180 ◽  
Author(s):  
Karina von der Malsburg ◽  
Sichen Shao ◽  
Ramanujan S. Hegde
Keyword(s):  
Quality Control ◽  
Cultured Cells ◽  
E3 Ligase ◽  
Cotranslational Translocation ◽  
Biochemical Analyses ◽  
Lateral Gate ◽  
Sec61 Channel ◽  
Cytosolic Ribosomes

Cytosolic ribosomes that stall during translation are split into subunits, and nascent polypeptides trapped in the 60S subunit are ubiquitinated by the ribosome quality control (RQC) pathway. Whether the RQC pathway can also target stalls during cotranslational translocation into the ER is not known. Here we report that listerin and NEMF, core RQC components, are bound to translocon-engaged 60S subunits on native ER membranes. RQC recruitment to the ER in cultured cells is stimulated by translation stalling. Biochemical analyses demonstrated that translocon-targeted nascent polypeptides that subsequently stall are polyubiquitinated in 60S complexes. Ubiquitination at the translocon requires cytosolic exposure of the polypeptide at the ribosome–Sec61 junction. This exposure can result from either failed insertion into the Sec61 channel or partial backsliding of translocating nascent chains. Only Sec61-engaged nascent chains early in their biogenesis were relatively refractory to ubiquitination. Modeling based on recent 60S–RQC and 80S–Sec61 structures suggests that the E3 ligase listerin accesses nascent polypeptides via a gap in the ribosome–translocon junction near the Sec61 lateral gate. Thus the RQC pathway can target stalled translocation intermediates for degradation from the Sec61 channel.

Experimental approaches to the study of the biogenesis of mammalian mitochondrial proteins

1986 ◽  
Vol 64 (11) ◽  
pp. 1108-1114 ◽  
Author(s):  
Karl B. Freeman ◽  
Randall W. Yatscoff ◽  
Robert G. Ridley
Keyword(s):  
Mitochondrial Proteins ◽  
Specific Inhibition ◽  
Mitochondrial Translation ◽  
Isolated Mitochondria ◽  
Approaches To Study ◽  
Experimental Approaches ◽  
Specific Inhibitors ◽  
Cytosolic Ribosomes

Mitochondrial proteins are synthesized in mitochondria and on cytosolic ribosomes. Several approaches used to establish the site of synthesis and the identity of mitochondrially synthesized proteins are described. These include the specific inhibition of mitochondrial translation by inhibitors or mutation and the specific elimination of cytosolic translation either by using isolated mitochondria or specific inhibitors. Experimental approaches to study the import of proteins into mitochondria are also discussed.

scholarly journals Regulation of mitochondrion-associated cytosolic ribosomes by mammalian mitochondrial ribonuclease T2 (RNASET2)

2018 ◽  
Vol 293 (51) ◽  
pp. 19633-19644 ◽  
Author(s):  
Jinliang Huang ◽  
Peipei Liu ◽  
Geng Wang
Keyword(s):  
Cytosolic Ribosomes

scholarly journals Proteomic LC–MS analysis of Arabidopsis cytosolic ribosomes: Identification of ribosomal protein paralogs and re-annotation of the ribosomal protein genes

2015 ◽  
Vol 128 ◽  
pp. 436-449 ◽  
Author(s):  
Maureen Hummel ◽  
Thomas Dobrenel ◽  
Jan (J.H.G.). Cordewener ◽  
Marlène Davanture ◽  
Christian Meyer ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Protein Genes ◽  
Ms Analysis ◽  
Protein Paralogs ◽  
Cytosolic Ribosomes

scholarly journals Biogenesis of cytosolic ribosomes requires the essential iron–sulphur protein Rli1p and mitochondria

2005 ◽  
Vol 24 (3) ◽  
pp. 589-598 ◽  
Author(s):  
Gyula Kispal ◽  
Katalin Sipos ◽  
Heike Lange ◽  
Zsuzsanna Fekete ◽  
Tibor Bedekovics ◽  
...  
Keyword(s):  
Cytosolic Ribosomes
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