Fluctuations in histone H4 isoforms during cellular reprogramming monitored by middle‐down proteomics
Bibliographic record
Abstract
Cellular reprogramming remodels the gene expression program by re-setting the epigenome of somatic cells into an embryonic-like pluripotent state. Post-translational modifications of histones play an important role in this process. Previously, we found by ChIP-seq widespread changes of specific histone H3 marks in two divergent reprogramming routes leading to alternative pluripotent sates . Here, using an unbiased middle-down proteomics approach we have identified 72 unique isoforms of histone H4 and quantified 56 of them in the same set of samples. We found substantial differences between somatic and late-phase reprogramming cells. Also, ESCs and iPSCs displayed higher levels of H4 acetylation and tri-methylation concomitantly with lower levels of mono- and di-methylation when compared to cells undergoing reprogramming. Our data shows that the epigenetic remodeling induced by the reprogramming process goes beyond histone H3 and reveals the importance of H4 modifications as well. The presented data is a valuable resource to study the epigenetic mechanisms involved in the acquisition of induced pluripotency. All MS data have been deposited in the ProteomeXchange with identifier PXD002062 (http://proteomecentral.proteomexchange.org/dataset/PXD002062).
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".