The role of Hsp90‐R2TP complex in snoRNP assembly and ribosomal RNA processing
Bibliographic record
Abstract
Box C/D snoRNPs, which typically consist of a snoRNA and four protein components (Nop1, Nop56, Nop58 and Snu13), play an essential role in the modification and processing of pre‐rRNA. Earlier, we had demonstrated that the Hsp90‐R2TP (Rvb1‐Rvb2‐Tah1‐Pih1) complex is involved in box C/D snoRNP biogenesis and assembly and, consequently, influences pre‐rRNA processing. Rvb1 and Rvb2 are AAA+ helicases, while Tah1 and Pih1 are Hsp90 cofactors/interactors. We had shown that the stability of the R2TP complex is modulated by Hsp90. More recently, we found, unexpectedly, that the activity of the R2TP complex is controlled by the dynamic subcellular redistribution of its protein components in response to growth conditions and nutrient limitation. In vigorously growing cells, the R2TP complex localizes in the nucleoplasm and interacts tightly with box C/D snoRNPs through Pih1, whereas, this interaction is significantly reduced in poorly growing cells. The R2TP complex is found to affect snoRNP levels by stabilizing Nop58. Our data suggest the presence of an unconventional communication pathway in which the Hsp90 chaperone stabilizes and promotes the assembly of the R2TP complex which in turn stabilizes and promotes the assembly of the box C/D snoRNP complexes. Our progress in this regard will be described in addition to our ongoing efforts aimed at the structural characterization of the R2TP complex.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".