Proteomic and 3D structure analyses highlight the C/D box snoRNP assembly mechanism and its control

Bizarro, Jonathan; Charron, Christophe; Boulon, Séverine; Westman, Belinda J.; Pradet‐Balade, Bérengère; Vandermoere, Franck; Chagot, M.E.; Hallais, Marie; Ahmad, Yasmeen; Leonhardt, Heinrich; Lamond, Angus I.; Manival, Xavier; Branlant, Christiane; Charpentier, Bruno; Verheggen, Céline; Bertrand, Édouard

doi:10.1083/jcb.201404160

Cited by 60 publications

(156 citation statements)

References 72 publications

(144 reference statements)

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“…As mentioned previously, ZNHIT6 and ZNHIT3 are snoRNP biogenesis factors that interact with NUFIP1 and the AAA+ ATPases91415. ZNHIT1 and INO80B/ZNHIT4 are components of chromatin remodelling complexes SRCAP and INO80, respectively, both of which also harbour a RUVBL1 and RUVBL2 module7.…”

Section: Resultsmentioning

confidence: 88%

R2TP/Prefoldin-like component RUVBL1/RUVBL2 directly interacts with ZNHIT2 to regulate assembly of U5 small nuclear ribonucleoprotein

et al. 2017

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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.

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Section: Resultsmentioning

confidence: 88%

R2TP/Prefoldin-like component RUVBL1/RUVBL2 directly interacts with ZNHIT2 to regulate assembly of U5 small nuclear ribonucleoprotein

et al. 2017

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“…Our affinity purification/mass spectrometry analyses confirmed the interaction of ECD with PRPF8. The R2TP complex regulates mRNA and ribosome biogenesis by facilitating the assembly of small nucleolar ribonucleoproteins (snoRNPs), which are known to be involved in spliceosome modification (51,52). Upregulation of R2TP and snoRNP components is thought to promote ribosome synthesis in cancer cells (47).…”

Section: Discussionmentioning

confidence: 99%

A Novel Interaction of Ecdysoneless (ECD) Protein with R2TP Complex Component RUVBL1 Is Required for the Functional Role of ECD in Cell Cycle Progression

Mir

Bele

Mirza

et al. 2016

Molecular and Cellular Biology

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Ecdysoneless (ECD) is an evolutionarily conserved protein whose germ line deletion is embryonic lethal. Deletion of Ecd in cells causes cell cycle arrest, which is rescued by exogenous ECD, demonstrating a requirement of ECD for normal mammalian cell cycle progression. However, the exact mechanism by which ECD regulates cell cycle is unknown. Here, we demonstrate that ECD protein levels and subcellular localization are invariant during cell cycle progression, suggesting a potential role of posttranslational modifications or protein-protein interactions. Since phosphorylated ECD was recently shown to interact with the PIH1D1 adaptor component of the R2TP cochaperone complex, we examined the requirement of ECD phosphorylation in cell cycle progression. Notably, phosphorylation-deficient ECD mutants that failed to bind to PIH1D1 in vitro fully retained the ability to interact with the R2TP complex and yet exhibited a reduced ability to rescue Ecd-deficient cells from cell cycle arrest. Biochemical analyses demonstrated an additional phosphorylation-independent interaction of ECD with the RUVBL1 component of the R2TP complex, and this interaction is essential for ECD's cell cycle progression function. These studies demonstrate that interaction of ECD with RUVBL1, and its CK2-mediated phosphorylation, independent of its interaction with PIH1D1, are important for its cell cycle regulatory function. P recisely regulated cell proliferation is essential for embryonic development as well as homeostasis in adult organs and tissues, whereas uncontrolled cell proliferation is a hallmark of cancer (1). A more in-depth understanding of the regulatory controls of cell cycle progression is therefore of great interest.The Ecd gene was originally inferred from studies of Drosophila melanogaster ecdysoneless (or ecd) mutants that exhibit defective development due to reduced production of the steroid hormone ecdysone (2). Subsequent cloning of drosophila ecd helped identify a cell-autonomous role of ECD protein in cell survival aside from its non-cell-autonomous role in ecdysis (molting) (3). However, the molecular basis of how ECD functions remains unknown (3). The human ECD homologue was initially identified in a screen of human open reading frames that complemented the S. cerevisiae mutants lacking Gcr2 (glycolysis regulation 2) gene, and it rescued the growth defect caused by reduced glycolytic enzyme activity in Gcr2 mutants. The human gene was initially designated HSGT1 (human suppressor of Gcr2) and was suggested to function as a coactivator of glycolytic gene transcription (4). However, ECD protein bears no structural homology to Gcr2, and a true ECD orthologue is absent in S. cerevisiae, suggesting that ECD likely functions by distinct mechanisms.We identified human ECD in a yeast two-hybrid screen of human mammary epithelial cell cDNA-encoded proteins for novel binding partners of the human papillomavirus 16 (HPV16) E6 oncogene (5). We showed that deletion of Ecd gene in mice causes embryonic lethality, identifying an esse...

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“…Interestingly, only ATP-loaded RUVBL1/2 can bind to ZNHIT6, whereas the binding of ATP releases RUVBL1/2 from R2TP 69,89 . This would suggest that it is the ATP loaded form of RUVBL1/2 that binds the pre-snoRNP complex and that the role of the HSP90/R2TP system would thus be to liberate RUVBL1/2 from R2TP to load them on the core proteins SNU13 and NOP58 84 . In agreement with this idea, yeast NOP58 mutants that fail to assemble with SNU13 interact more strongly with yeast R2TP and in particular with the yeast homologs of PIH1D1 and RPAP3 78 …”

Section: Introductionmentioning

confidence: 99%

“…In higher eukaryotes, NOP58 lacks the DSDD motif. These organisms however have the C12orf45 factor, which tighly associates with NOP58 and may mediate its interaction with the R2TP 84 . Thus, the details of interactions might differ substantially between yeast and human systems, in agreement with rather important differences between the homologs of PIH1D1 and RPAP3.…”

Section: Introductionmentioning

confidence: 99%

Assembly and trafficking of box C/D and H/ACA snoRNPs

2016

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Box C/D and box H/ACA snoRNAs are abundant non-coding RNAs that localize in the nucleolus and mostly function as guides for nucleotide modifications. While a large pool of snoRNAs modifies rRNAs, an increasing number of snoRNAs could also potentially target mRNAs. ScaRNAs belong to a family of specific RNAs that localize in Cajal bodies and that are structurally similar to snoRNAs. Most scaRNAs are involved in snRNA modification, while telomerase RNA, which contains H/ACA motifs, functions in telomeric DNA synthesis. In this review, we describe how box C/D and H/ACA snoRNAs are processed and assembled with core proteins to form functional RNP particles. Their biogenesis involve several transport factors that first direct pre-snoRNPs to Cajal bodies, where some processing steps are believed to take place, and then to nucleoli. Assembly of core proteins involves the HSP90/R2TP chaperone-cochaperone system for both box C/D and H/ACA RNAs, but also several factors specific for each family. These assembly factors chaperone unassembled core proteins, regulate the formation and disassembly of pre-snoRNP intermediates, and control the activity of immature particles. The AAA+ ATPase RUVBL1 and RUVBL2 belong to the R2TP co-chaperones and play essential roles in snoRNP biogenesis, as well as in the formation of other macro-molecular complexes. Despite intensive research, their mechanisms of action are still incompletely understood.

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Proteomic and 3D structure analyses highlight the C/D box snoRNP assembly mechanism and its control

Abstract: During small nucleolar ribonucleoprotein complex assembly, a pre-snoRNP complex consisting only of protein components forms first, followed by displacement of the ZNHIT3 subunit when C/D snoRNAs bind and dynamic loading and unloading of RuvBL AAA+ ATPases.

Cited by 60 publications

References 72 publications

R2TP/Prefoldin-like component RUVBL1/RUVBL2 directly interacts with ZNHIT2 to regulate assembly of U5 small nuclear ribonucleoprotein

R2TP/Prefoldin-like component RUVBL1/RUVBL2 directly interacts with ZNHIT2 to regulate assembly of U5 small nuclear ribonucleoprotein

A Novel Interaction of Ecdysoneless (ECD) Protein with R2TP Complex Component RUVBL1 Is Required for the Functional Role of ECD in Cell Cycle Progression

Assembly and trafficking of box C/D and H/ACA snoRNPs

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