Abstract
The R2TP/Prefoldin-like (R2TP/PFDL) complex has emerged as a cochaperone complex involved in the assembly of a number of critical protein complexes including snoRNPs, nuclear RNA polymerases and PIKK-containing complexes. Here we report on the use of multiple target affinity purification coupled to mass spectrometry to identify two additional complexes that interact with R2TP/PFDL: the TSC1-TSC2 complex and the U5 small nuclear ribonucleoprotein (snRNP). The interaction between R2TP/PFDL and the U5 snRNP is mostly mediated by the previously uncharacterized factor ZNHIT2. A more general function for the zinc-finger HIT domain in binding RUVBL2 is exposed. Disruption of ZNHIT2 and RUVBL2 expression impacts the protein composition of the U5 snRNP suggesting a function for these proteins in promoting the assembly of the ribonucleoprotein. A possible implication of R2TP/PFDL as a major effector of stress-, energy- and nutrient-sensing pathways that regulate anabolic processes through the regulation of its chaperoning activity is discussed.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATPases Associated with Diverse Cellular Activities / genetics
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ATPases Associated with Diverse Cellular Activities / metabolism*
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Alternative Splicing / genetics
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Cell Line
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DNA Helicases / genetics
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DNA Helicases / metabolism*
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Energy Metabolism / genetics
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HEK293 Cells
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HeLa Cells
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Humans
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Phosphoproteins / genetics
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Phosphoproteins / metabolism*
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RNA, Small Interfering / genetics
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Ribonucleoprotein, U5 Small Nuclear / biosynthesis*
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TOR Serine-Threonine Kinases / metabolism
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Tuberous Sclerosis Complex 1 Protein
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Tuberous Sclerosis Complex 2 Protein
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Tumor Suppressor Proteins / metabolism*
Substances
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Carrier Proteins
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Phosphoproteins
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RNA, Small Interfering
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Ribonucleoprotein, U5 Small Nuclear
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TSC1 protein, human
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TSC2 protein, human
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Tuberous Sclerosis Complex 1 Protein
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Tuberous Sclerosis Complex 2 Protein
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Tumor Suppressor Proteins
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ZNHIT2 protein, human
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MTOR protein, human
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TOR Serine-Threonine Kinases
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ATPases Associated with Diverse Cellular Activities
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DNA Helicases
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RUVBL1 protein, human
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RUVBL2 protein, human