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Kinetics of re-establishing H3K79 methylation marks in global human chromatin.

ABSTRACT: We employ a stable isotope strategy wherein both histones and their methylations are labeled in synchronized human cells. This allows us to differentiate between old and new methylations on pre-existing versus newly synthesized histones. The strategy is implemented on K79 methylation in an isoform-specific manner for histones H3.1, H3.2, and H3.3. Although levels of H3.3K79 monomethylation are higher than that of H3.2/H3.1, the rate of establishing the K79 methylation is the same for all three isoforms. Surprisingly, we find that pre-existing "old" histones continue to be K79-monomethylated and -dimethylated at a rate equal to the newly synthesized histones. These observations imply that some degree of positional "scrambling" of K79 methylation occurs through the cell cycle.

SUBMITTER: Sweet SM

PROVIDER: S-EPMC2963384 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature

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Kinetics of re-establishing H3K79 methylation marks in global human chromatin.

Sweet Steve M M SMM Li Mingxi M Thomas Paul M PM Durbin Kenneth R KR Kelleher Neil L NL

The Journal of biological chemistry 20100809 43

We employ a stable isotope strategy wherein both histones and their methylations are labeled in synchronized human cells. This allows us to differentiate between old and new methylations on pre-existing versus newly synthesized histones. The strategy is implemented on K79 methylation in an isoform-specific manner for histones H3.1, H3.2, and H3.3. Although levels of H3.3K79 monomethylation are higher than that of H3.2/H3.1, the rate of establishing the K79 methylation is the same for all three i ...[more]

PMID: 20699226

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