Subcellular localization of the yeast proteome
Proteome survey reveals modularity of the yeast cell machinery
Global landscape of protein complexes in the yeast Saccharomyces cerevisiae
Co-translational capturing of nascent ribosomal proteins by their dedicated chaperones
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Sqt1 is a dedicated chaperone for Rpl10 and shields Rpl10's N-terminal rRNA-binding residues during incorporation into pre-60S subunits.
"Affinity purification of four chaperones (Rrb1, Syo1, Sqt1 and Yar1) selectively enriched the mRNAs encoding their specific ribosomal protein clients (Rpl3, Rpl5, Rpl10 and Rps3). X-ray crystallography reveals how the N-terminal, rRNA-binding residues of Rpl10 are shielded by Sqt1's WD-repeat beta-propeller."
An inter-species protein-protein interaction network across vast evolutionary distance
Chaperone-directed ribosome repair after oxidative damage.
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Sqt1 releases oxidized Rpl10 from mature ribosomes and supports replacement with newly synthesized Rpl10, extending its carrier-chaperone activity from 60S assembly to ribosome repair under oxidative stress.
"Oxidized Rps26 and Rpl10 are released from ribosomes by their chaperones, Tsr2 and Sqt1, and the damaged ribosomes are subsequently repaired with newly made proteins."
The social and structural architecture of the yeast protein interactome
Ribosome Assembly and Repair.
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A 2024 review summarizes Sqt1/Tsr2-dependent replacement of oxidized Rpl10 and Rps26 as a chaperone-directed repair mechanism in idle 80S ribosomes.
"To mitigate the harm from dysfunctional ribosomes, the damaged proteins are then selectively released from ribosomes via their chaperones Tsr2 and Sqt1, respectively, to allow for their relatively rapid turnover."
SQT1, which encodes an essential WD domain protein of Saccharomyces cerevisiae, suppresses dominant-negative mutations of the ribosomal protein gene QSR1
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Sqt1 is required for late 60S subunit assembly or modification in the cytoplasm.
"Loss of SQT1 function by down regulation from an inducible promoter results in formation of half-mer polyribosomes and decreased Qsr1p levels on free 60S subunits."
Falcon deep research report for SQT1
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Falcon supports SQT1 as a cytosolic Rpl10 carrier chaperone required for late 60S maturation and ribosome homeostasis.
"Sqt1 is an essential cytoplasmic WD40-repeat beta-propeller protein that functions as a dedicated chaperone/escortin for ribosomal protein Rpl10/uL16."