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Histone H3 serine 57 and lysine 56 interplay in transcription elongation and recovery from S-phase stress.

Aslam A, Logie C - PLoS ONE (2010)

Bottom Line: Because phosphorylated human histone H3 serine 57 peptides have been detected by mass spectrometry we examined whether H3-S57 phosphorylation interplays with H3-K56 acetylation in vivo.Strikingly, opposite results were obtained in the context of a serine to alanine substitution at position 57 of histone H3.We speculate that histone H3-S57 couples H3-K56 acetylation to histone quaternary structures involving arginine 40 on histone H4 helix 1.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, The Netherlands.

ABSTRACT

Background: Acetylation of lysine 56 of histone H3 plays an important role in the DNA damage response and it has been postulated to play an as yet undefined role in transcription, both in yeast and in higher eukaryotes. Because phosphorylated human histone H3 serine 57 peptides have been detected by mass spectrometry we examined whether H3-S57 phosphorylation interplays with H3-K56 acetylation in vivo.

Methodology/principal findings: To explore the physiological role of H3-S57, H3-K56 was mutated to mimic constitutively (un)acetylated forms of H3-K56 and these were combined with constitutively (un)phosphorylated mimics of H3-S57, in yeast. A phosphorylated serine mimic at position 57 lessened sensitivities to a DNA replication fork inhibitor and to a transcription elongation inhibitor that were caused by an acetylated lysine mimic at position 56, while the same substitution exacerbated sensitivities due to mimicking a constitutive non-acetylated lysine at position 56. Strikingly, opposite results were obtained in the context of a serine to alanine substitution at position 57 of histone H3.

Conclusions/significance: The phenotypes elicited and the context-dependent interplay of the H3-K56 and -S57 point mutations that mimic their respective modification states suggest that serine 57 phosphorylation promotes a nucleosomal transaction when lysine 56 is acetylated. We speculate that histone H3-S57 couples H3-K56 acetylation to histone quaternary structures involving arginine 40 on histone H4 helix 1.

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Lack of dominant negative effects of the H3-K56/H3S57 mutant histone genes.The plasmid-borne H3-K56 (Q, R) and -S57 (A, E) hht2 point mutations were analyzed for dominant negative effects in YN1038, a strain harboring wild type chromosomal copies of the HHT2 and HHT1 yeast histone H3 genes. Neither growth rates measured at 30°C (A) and nor clone sizes determined on plates containing methyl methanesulfonate, hydroxyurea or formamide (B) revealed any dominant effects of the mutant histone H3 genes when wild type yeast histone H3 was present.
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pone-0010851-g001: Lack of dominant negative effects of the H3-K56/H3S57 mutant histone genes.The plasmid-borne H3-K56 (Q, R) and -S57 (A, E) hht2 point mutations were analyzed for dominant negative effects in YN1038, a strain harboring wild type chromosomal copies of the HHT2 and HHT1 yeast histone H3 genes. Neither growth rates measured at 30°C (A) and nor clone sizes determined on plates containing methyl methanesulfonate, hydroxyurea or formamide (B) revealed any dominant effects of the mutant histone H3 genes when wild type yeast histone H3 was present.

Mentions: In order to explore whether H3-S57 interplays with H3-K56 acetylation we employed a Saccharomyces cerevisiae yeast strain where both endogenous H3 genes were deleted. The yeast were kept alive with a counter-selectable plasmid driving expression of wild type histone H3 [3]. Mutations were introduced on a second H3 expression plasmid and phenotypes were assessed in the presence or absence of the plasmid bearing the wild type H3 allele. Mutations replaced lysine 56 with alanine, arginine or glutamine, eliminating lysine function, mimicking an non-acetylated lysine or mimicking a constitutively acetylated lysine, respectively. These were then combined with serine 57 substitutions into alanine, or glutamate, eliminating serine function or mimicking a phosphorylated serine, respectively. We did not detect any dominant effects at the level of growth rates or any of the tested phenotypes in yeast harboring both the wild type and any mutant version of histone H3 (Figure 1). Furthermore, and in contrast to introduction of a glutamate at position 56 which is lethal [3], [33], all of the above single and double mutations – including a glutamate at position 57 – could support life, as we obtained viable mutant yeast clones with similar frequencies (Figure 2).


Histone H3 serine 57 and lysine 56 interplay in transcription elongation and recovery from S-phase stress.

Aslam A, Logie C - PLoS ONE (2010)

Lack of dominant negative effects of the H3-K56/H3S57 mutant histone genes.The plasmid-borne H3-K56 (Q, R) and -S57 (A, E) hht2 point mutations were analyzed for dominant negative effects in YN1038, a strain harboring wild type chromosomal copies of the HHT2 and HHT1 yeast histone H3 genes. Neither growth rates measured at 30°C (A) and nor clone sizes determined on plates containing methyl methanesulfonate, hydroxyurea or formamide (B) revealed any dominant effects of the mutant histone H3 genes when wild type yeast histone H3 was present.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2877106&req=5

pone-0010851-g001: Lack of dominant negative effects of the H3-K56/H3S57 mutant histone genes.The plasmid-borne H3-K56 (Q, R) and -S57 (A, E) hht2 point mutations were analyzed for dominant negative effects in YN1038, a strain harboring wild type chromosomal copies of the HHT2 and HHT1 yeast histone H3 genes. Neither growth rates measured at 30°C (A) and nor clone sizes determined on plates containing methyl methanesulfonate, hydroxyurea or formamide (B) revealed any dominant effects of the mutant histone H3 genes when wild type yeast histone H3 was present.
Mentions: In order to explore whether H3-S57 interplays with H3-K56 acetylation we employed a Saccharomyces cerevisiae yeast strain where both endogenous H3 genes were deleted. The yeast were kept alive with a counter-selectable plasmid driving expression of wild type histone H3 [3]. Mutations were introduced on a second H3 expression plasmid and phenotypes were assessed in the presence or absence of the plasmid bearing the wild type H3 allele. Mutations replaced lysine 56 with alanine, arginine or glutamine, eliminating lysine function, mimicking an non-acetylated lysine or mimicking a constitutively acetylated lysine, respectively. These were then combined with serine 57 substitutions into alanine, or glutamate, eliminating serine function or mimicking a phosphorylated serine, respectively. We did not detect any dominant effects at the level of growth rates or any of the tested phenotypes in yeast harboring both the wild type and any mutant version of histone H3 (Figure 1). Furthermore, and in contrast to introduction of a glutamate at position 56 which is lethal [3], [33], all of the above single and double mutations – including a glutamate at position 57 – could support life, as we obtained viable mutant yeast clones with similar frequencies (Figure 2).

Bottom Line: Because phosphorylated human histone H3 serine 57 peptides have been detected by mass spectrometry we examined whether H3-S57 phosphorylation interplays with H3-K56 acetylation in vivo.Strikingly, opposite results were obtained in the context of a serine to alanine substitution at position 57 of histone H3.We speculate that histone H3-S57 couples H3-K56 acetylation to histone quaternary structures involving arginine 40 on histone H4 helix 1.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, The Netherlands.

ABSTRACT

Background: Acetylation of lysine 56 of histone H3 plays an important role in the DNA damage response and it has been postulated to play an as yet undefined role in transcription, both in yeast and in higher eukaryotes. Because phosphorylated human histone H3 serine 57 peptides have been detected by mass spectrometry we examined whether H3-S57 phosphorylation interplays with H3-K56 acetylation in vivo.

Methodology/principal findings: To explore the physiological role of H3-S57, H3-K56 was mutated to mimic constitutively (un)acetylated forms of H3-K56 and these were combined with constitutively (un)phosphorylated mimics of H3-S57, in yeast. A phosphorylated serine mimic at position 57 lessened sensitivities to a DNA replication fork inhibitor and to a transcription elongation inhibitor that were caused by an acetylated lysine mimic at position 56, while the same substitution exacerbated sensitivities due to mimicking a constitutive non-acetylated lysine at position 56. Strikingly, opposite results were obtained in the context of a serine to alanine substitution at position 57 of histone H3.

Conclusions/significance: The phenotypes elicited and the context-dependent interplay of the H3-K56 and -S57 point mutations that mimic their respective modification states suggest that serine 57 phosphorylation promotes a nucleosomal transaction when lysine 56 is acetylated. We speculate that histone H3-S57 couples H3-K56 acetylation to histone quaternary structures involving arginine 40 on histone H4 helix 1.

Show MeSH
Related in: MedlinePlus