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Updated: Aug 9, 2026
Purification of H3 and H4 Histone Proteins and the Quantification of Acetylated Histone Marks in Cells and Brain Tissue
Published on: November 30, 2018
Acetylation of MyoD by p300 requires more than its histone acetyltransferase domain
1CNRS UPR 9079, Institut André Lwoff, 7 Rue Guy Moquet, 94800 Villejuif, France.
Abstract:
MyoD, an essential transcription factor involved in muscle cell terminal differentiation, is regulated by acetylation, as are a number of other transcription factors, but the histone acetyltransferase enzyme responsible for this acetylation is a matter of controversy. In particular, contradictory findings have been reported concerning the ability of CBP/p300 to acetylate MyoD in vitro. Here we provide an explanation for this discrepancy: although full-length p300 does indeed acetylate MyoD, a fragment of p300 corresponding to its histone acetyltransferase domain does not. In addition to clearly demonstrating that p300 acetylates MyoD in vitro, these results underscore the necessity of using full-length histone acetyltransferase enzymes to draw valid conclusions from acetylation experiments.
Insights
Full-length p300 acetylates MyoD, resolving controversy over its role in muscle differentiation. Using full enzyme length is crucial for accurate in vitro acetylation studies.
Area of Science:
- Molecular Biology
- Cellular Differentiation
- Epigenetics
Background:
- MyoD is a key transcription factor for muscle cell differentiation.
- Acetylation regulates transcription factors, but the responsible enzymes are debated.
- Previous studies showed conflicting results on p300's ability to acetylate MyoD.
Purpose of the Study:
- To clarify the role of CBP/p300 in MyoD acetylation.
- To explain discrepancies in previous in vitro findings.
- To emphasize the importance of using full-length enzymes in acetylation assays.
Main Methods:
- In vitro acetylation assays using full-length p300.
- In vitro acetylation assays using a p300 histone acetyltransferase domain fragment.
- Analysis of MyoD acetylation.
Main Results:
- Full-length p300 successfully acetylated MyoD in vitro.
- A fragment of p300 lacking the full enzyme structure did not acetylate MyoD.
- This demonstrates p300's direct role in MyoD acetylation.
Conclusions:
- Full-length p300 acetylates MyoD, resolving prior experimental discrepancies.
- The use of full-length histone acetyltransferase enzymes is essential for valid in vitro acetylation studies.
- This finding clarifies a key regulatory mechanism in muscle cell differentiation.
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