UniProt:Q12532 RQC2

chain
  • chain:1-1038
checksum C0ADE76922F26BE0
comment
  • 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 (PubMed:20691087, PubMed:23178123, PubMed:23479637, PubMed:25349383, PubMed:25554787, PubMed:26934223, PubMed:28751611, PubMed:32934225). 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 (PubMed:23178123). Within the RQC complex, 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 (PubMed:23479637, PubMed:25349383). Following binding to stalled 60S ribosomal subunits, 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) (PubMed:25554787, PubMed:26934223, PubMed:27129255, PubMed:28751611, PubMed:32934225, PubMed:36804914). 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 (PubMed:28751611, PubMed:32934225). Following ubiquitination, incompletely synthesized nascent polypeptides are recognized by CDC48 and degraded by the proteasome (PubMed:27129255). 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 (PubMed:26934223, PubMed:27129255, PubMed:31133701).SUBUNIT Component of the ribosome quality control complex (RQC), composed of the E3 ubiquitin ligase RKR1/LTN1, RQC1 and RQC2, as well as CDC48 and its ubiquitin-binding cofactors associated with the 60S ribosomal subunit (PubMed:23178123, PubMed:23479637, PubMed:25349383). RQC2 binds to the 40S-binding surface of tRNAs (PubMed:25554787).INTERACTION Present with 7700 molecules/cell in log phase SD medium.SIMILARITY Belongs to the NEMF family.
created [InstanceEdit:217385] Schmidt, EE, 2008-03-27 06:23:53
crossReference
databaseName UniProt
dbId 256816
description
  • recommendedName: fullName evidence="17"Ribosome quality control complex subunit 2 alternativeName: fullName evidence="16"Translation-associated element 2
displayName UniProt:Q12532 RQC2
geneName
  • RQC2
  • TAE2
  • YPL009C
  • YP8132.04C
identifier Q12532
isSequenceChanged false
keyword
  • 3D-structure
  • Coiled coil
  • Cytoplasm
  • Phosphoprotein
  • Protein biosynthesis
  • Reference proteome
modified [InstanceEdit:9983091] Weiser, Joel, 2026-02-20
moleculeType Protein
name
  • RQC2
otherIdentifier
  • 856098
  • GO:0000049
  • GO:0003674
  • GO:0003723
  • GO:0003729
  • GO:0005575
  • GO:0005737
  • GO:0005840
  • GO:0006412
  • GO:0006414
  • GO:0010494
  • GO:0022626
  • GO:0043023
  • GO:0043043
  • GO:0051603
  • GO:0072344
  • GO:0140708
  • GO:1904678
  • GO:1990112
  • GO:1990116
physicalEntity
referenceDatabase [ReferenceDatabase:2] UniProt
referenceGene
referenceTranscript
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • RQC2_YEAST
  • D6W403
sequenceLength 1038
species [Species:68322] Saccharomyces cerevisiae
stId uniprot:Q12532
url http://purl.uniprot.org/uniprot/Q12532
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