Q9USN8 · RQC2_SCHPO

Function

function

Key component of the ribosome quality control complex (RQC), a ribosome-associated complex that mediates the extraction of incompletely synthesized nascent chains from stalled ribosomes as well as their ubiquitin-mediated proteasomal degradation. Thereby, frees 60S subunit ribosomes from the stalled translation complex and prevents the accumulation of nascent polypeptide chains that are potentially toxic for the cell. Within the RQC complex, mtr1/rqc2 specifically binds stalled 60S ribosomal subunits by recognizing an exposed, nascent chain-conjugated tRNA moiety and promotes the recruitment of rkr1/ltn1 to stalled 60S subunits. Following binding to stalled 60S ribosomal subunits, mtr1/rqc2 mediates CAT tailing by recruiting alanine- and threonine-charged tRNA to the A-site and directing the elongation of stalled nascent chains independently of mRNA or 40S subunits, leading to non-templated C-terminal Ala and Thr extensions (CAT tails). CAT tails promote the rkr1/ltn1-mediated ubiquitination of incompletely synthesized nascent polypeptides: CAT tailing facilitates rkr1/ltn1-dependent ubiquitination by exposing lysine residues that would otherwise remain buried in the ribosomal exit tunnel. Following ubiquitination, incompletely synthesized nascent polypeptides are recognized by CDC48 and degraded by the proteasome. CAT-tailed proteins tend to aggregate and sequester chaperones and can induce proteotoxic stress; their rkr1/ltn1-dependent ubiquitination and degradation is required to prevent proteotoxic stress.

GO annotations

all annotationsall molecular functionvirus receptor activitydna bindingrna bindingcytoskeletal motor activitycatalytic activitygtpase activitystructural molecule activitytransporter activitycytoskeletal protein bindinglipid bindingcyclase activityantioxidant activityoxidoreductase activitytransferase activityhydrolase activitylyase activityisomerase activityligase activityprotein tag activitycargo receptor activityhistone bindingprotein folding chaperonetranslation regulator activitynutrient reservoir activityreceptor ligand activitymolecular transducer activitymolecular adaptor activitytoxin activitycell adhesion mediator activitymolecular function regulator activityvirus coreceptor activitycatalytic activity, acting on a proteincatalytic activity, acting on dnacatalytic activity, acting on rnamolecular carrier activitytranscription regulator activitygeneral transcription initiation factor activitymolecular sensor activitymolecular sequestering activityatp-dependent activityother molecular functionall biological processmitotic cell cyclecytokinesiscytoplasmic translationimmune system processmuscle system processcirculatory system processrenal system processrespiratory system processcarbohydrate metabolic processgeneration of precursor metabolites and energydna replicationdna repairdna recombinationchromatin organizationdna-templated transcriptionregulation of dna-templated transcriptiontrna metabolic processprotein foldingprotein glycosylationamino acid metabolic processmodified amino acid metabolic processlipid metabolic processvitamin metabolic processsulfur compound metabolic processintracellular protein transportnucleocytoplasmic transportautophagyinflammatory responsemitochondrion organizationcytoskeleton organizationmicrotubule-based movementperoxisome organizationlysosome organizationchromosome segregationcell adhesionestablishment or maintenance of cell polarityprogrammed cell deathphotosynthesismrna metabolic processsnrna metabolic processvesicle-mediated transportreproductive processdigestive system processsignalingcell differentiationprotein catabolic processextracellular matrix organizationregulatory ncrna-mediated gene silencingtelomere organizationcell junction organizationwound healingribosome biogenesiscilium organizationanatomical structure developmentcell motilitynervous system processendocrine processprotein maturationtransmembrane transportnucleobase-containing small molecule metabolic processhepaticobiliary system processmembrane organizationprotein-containing complex assemblycell wall organization or biogenesisnitrogen cycle metabolic processprotein localization to plasma membranedefense response to other organismdetoxificationmeiotic nuclear divisionmitotic nuclear divisionmitochondrial gene expressioncarbohydrate derivative metabolic processother biological processall cellular componentnuclear chromosomeextracellular regionextracellular spacecell wallnucleusnuclear envelopenucleoplasmchromosomenucleolusmitochondrionlysosomeendosomevacuoleperoxisomeendoplasmic reticulumgolgi apparatuslipid dropletmicrotubule organizing centercytosolribosomecytoskeletonplasma membraneciliumplastidthylakoidexternal encapsulating structureextracellular matrixcytoplasmic vesicleorganelleother cellular component
Cell color indicative of number of GO terms
AspectTerm
Cellular Componentcytoplasm
Cellular Componentcytosol
Cellular ComponentRQC complex
Molecular Functionribosomal large subunit binding
Molecular FunctiontRNA binding
Biological ProcessCAT tailing
Biological Processrescue of stalled ribosome
Biological Processribosome-associated ubiquitin-dependent protein catabolic process

Names & Taxonomy

Protein names

  • Recommended name
    Ribosome quality control complex subunit 2
  • Alternative names
    • Microtubule regulator protein 1

Gene names

    • Name
      mtr1
    • ORF names
      SPCC132.01c
      , SPCC1322.17c

Organism names

Accessions

  • Primary accession
    Q9USN8
  • Secondary accessions
    • O94551

Proteomes

Organism-specific databases

Subcellular Location

Keywords

PTM/Processing

Features

Showing features for chain, modified residue.

TypeIDPosition(s)Description
ChainPRO_00001168201-1021Ribosome quality control complex subunit 2
Modified residue478Phosphoserine

Keywords

Proteomic databases

PTM databases

Interaction

Subunit

Component of the ribosome quality control complex (RQC), composed of the E3 ubiquitin ligase rkr1/ltn1, rqc1 and mtr1/rqc2, as well as cdc48 and its ubiquitin-binding cofactors associated with the 60S ribosomal subunit. RQC2 binds to the 40S-binding surface of tRNAs.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for coiled coil, region, compositional bias.

TypeIDPosition(s)Description
Coiled coil348-388
Region457-484Disordered
Compositional bias465-480Acidic residues
Coiled coil507-546
Coiled coil698-727
Compositional bias746-762Polar residues
Region746-801Disordered
Compositional bias763-800Basic and acidic residues
Region832-905Disordered
Compositional bias839-859Polar residues
Compositional bias877-905Basic and acidic residues

Sequence similarities

Belongs to the NEMF family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    1,021
  • Mass (Da)
    114,240
  • Last updated
    2004-03-29 v2
  • Checksum
    5308EEA9AEC52178
MKQRFSALDIAAIAAELREQVVGCRLNNFYDLNARTFLLKFGKQDAKYSIVIESGFRAHLTKFDRENAPLSGFVTKLRKHIKSRRLTGVSQLGTDRVLVFTFGGGANDQDPDWTYYLVCEFFAAGNVLLLDGHYKILSLLRVVTFDKDQVYAVGQKYNLDKNNLVNDNKSQSTIPHMTAERLNILLDEISTAYASPTSINEPLPDQQLSSSTKPIKVPKPVSLRKALTIRLGEYGNALIEHCLRRSKLDPLFPACQLCADETKKNDLLAAFQEADSILAAVNKPPVKGYIFSLEQALTNAADPQHPEECTTLYEDFHPFQPLQLVQANRKCMEFPTYNECVDEFFSSIEAQKLKKRAHDRLATAERRLESAKEDQARKLQSLQDAQATCALRAQAIEMNPELVEAIISYINSLLNQGMDWLDIEKLIQSQKRRSPVAAAIQIPLKLIKNAVTVFLPNPESVDNSDESSETSDDDLDDSDDDNKVKEGKVSSKFIAVELDLSLGAFANARKQYELRREALIKETKTAEAASKALKSTQRKIEQDLKRSTTADTQRILLGRKTFFFEKFHWFISSEGYLVLGGRDAQQNELLFQKYCNTGDIFVCADLPKSSIIIVKNKNPHDPIPPNTLQQAGSLALASSKAWDSKTVISAWWVRIDEVSKLAPTGEILPTGSFAIRAKKNYLPPTVLIMGYGILWQLDEKSSERRKARRLEMEVVETQGKVSELKMEGTSVTSEDNIQDVVSEVSYNEDTNNQSTPDTTGSDIHIVSEKRGKKGSKVITAKKVSAKERREARRARRQTALEESLKAPISIEDATDPQTILAILKQKKAKKKHAAREMEISSQIPSNDSSNVQTPTAESEIEEDGVSEPISAEVIEDQSRNSEAENEKGLSTEQRDEKKHAKVESFQRQEMPRSLFEEIFFAIDSLTPNPQQQDTVINAVPTFAPYNAMTKFNQKVKVMPGTGKVGKAARESIAYFMKKLPKSSKEAAYLENLKDGEIVAPISVSRLKMVFGSSGNTKKSKK

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias465-480Acidic residues
Compositional bias746-762Polar residues
Compositional bias763-800Basic and acidic residues
Compositional bias839-859Polar residues
Compositional bias877-905Basic and acidic residues

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CU329672
EMBL· GenBank· DDBJ
CAA22870.2
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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