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Yeast contains multiple forms of histone acetyltransferase
G López-Rodas1, V Tordera, M M Sánchez del Pino
1Department of Biochemistry and Molecular Biology, Faculties of Sciences, University of Valencia, Spain.
The Journal of Biological Chemistry
|November 15, 1989
Summary
Researchers identified multiple yeast histone acetyltransferases, enzymes crucial for gene regulation. These enzymes show specificity for different histone proteins, suggesting diverse roles in cellular processes.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Histone acetylation is a key epigenetic modification regulating gene expression.
- Understanding the enzymes responsible for histone acetylation (histone acetyltransferases or HATs) is crucial for deciphering gene regulation mechanisms.
Purpose of the Study:
- To quantitatively recover and characterize yeast histone acetyltransferases (HATs).
- To investigate the multiplicity and substrate specificity of yeast HATs.
- To differentiate between various HAT activities based on their chromatographic behavior and substrate preference.
Main Methods:
- Assaying multiple methods for quantitative recovery of yeast HATs, including ammonium sulfate precipitation and salt dissociation of chromatin.
- Utilizing DEAE-Sepharose chromatography to separate and partially purify HAT activities.
- Employing cation-exchange chromatography for further resolution of enzyme activities.
- Determining specific activity against individual histones (H2B, H3, H4) using [14C]acetyl-CoA.
Main Results:
- Two methods yielded convenient preparations of total yeast HATs.
- DEAE-Sepharose chromatography revealed three peaks of activity with total histones, but four peaks when individual histones were analyzed.
- Two distinct HAT activities were resolved, one specific for H2B and another for H3.
- Two H4-specific HAT activities were identified, one chromatin-bound and one cytoplasmic.
- The H2B-specific enzyme was found to acetylate chicken erythrocyte H2A.
Conclusions:
- Yeast possesses multiple distinct histone acetyltransferase enzymes.
- These enzymes exhibit specificities towards different histone substrates (H2B, H3, H4).
- The identified HAT multiplicity likely reflects the diverse functional roles of histone acetylation in yeast.