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Patterns of histone acetylation in Physarum polycephalum. H2A and H2B acetylation is functionally distinct from H3
Abstract:
Histone acetylation has previously been correlated with both chromosome replication and transcription. We present evidence that (a) confirms both correlations in the true slime mold, Physarum polycephalum and (b) shows that quite a different pattern of acetate turnover is associated with replication compared with transcription. The pattern associated with replication involves turnover of acetate on all four core histones on species containing one or two acetates per molecule. This pattern was resolved from the transcription-associated pattern by three different procedures: (a) detailed analysis of gels of histones pulse-labelled with acetate; (b) the pattern of acetylation of histones pulse-labelled with [3H]lysine; and (c) the pattern of acetylation of soluble histones. The pattern associated with transcription is restricted to histones H3 and H4 and occurs mostly on highly acetylated species. This pattern was resolved by (a) analysis of gels of histones pulse-labelled with acetate; (b) the pattern of histone acetylation in G2 phase of the cell cycle; and (c) the pattern of histone acetylation in the presence of cycloheximide.
Insights
Histone acetylation patterns differ between chromosome replication and transcription in Physarum polycephalum. Replication involves all core histones, while transcription focuses on H3 and H4 acetylation.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Histone acetylation is linked to DNA replication and gene transcription.
- Understanding these distinct roles is crucial for cell cycle regulation.
Purpose of the Study:
- To investigate and differentiate histone acetylation patterns during replication versus transcription in Physarum polycephalum.
- To confirm the correlation of histone acetylation with both processes.
Main Methods:
- Pulse-labeling of histones with acetate and [3H]lysine.
- Analysis of histone acetylation patterns on gels.
- Examination of histone acetylation during G2 phase and in the presence of cycloheximide.
Main Results:
- Replication-associated acetylation involves all four core histones.
- Transcription-associated acetylation is specific to histones H3 and H4.
- Distinct acetate turnover patterns were observed for replication and transcription.
Conclusions:
- Histone acetylation plays differential roles in chromosome replication and transcription.
- Physarum polycephalum provides a model for studying these distinct acetylation dynamics.