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Histone H3 tail clipping regulates gene expression.

Santos-Rosa H, Kirmizis A, Nelson C, Bartke T, Saksouk N, Cote J, Kouzarides T - Nat. Struct. Mol. Biol. (2008)

Bottom Line: Induction of gene expression in yeast and human cells involves changes in the histone modifications associated with promoters.A truncated H3 product is not generated in yeast carrying a mutation of the endopeptidase recognition site (H3 Q19A L20A) and gene induction is defective in these cells.These findings identify clipping of H3 tails as a previously uncharacterized modification of promoter-bound nucleosomes, which may result in the localized clearing of repressive signals during the induction of gene expression.

View Article: PubMed Central - PubMed

Affiliation: Gurdon Institute and Department of Pathology, Tennis Court Road, Cambridge CB2 1QN, UK.

ABSTRACT
Induction of gene expression in yeast and human cells involves changes in the histone modifications associated with promoters. Here we identify a histone H3 endopeptidase activity in Saccharomyces cerevisiae that may regulate these events. The endopeptidase cleaves H3 after Ala21, generating a histone that lacks the first 21 residues and shows a preference for H3 tails carrying repressive modifications. In vivo, the H3 N terminus is clipped, specifically within the promoters of genes following the induction of transcription. H3 clipping precedes the process of histone eviction seen when genes become fully active. A truncated H3 product is not generated in yeast carrying a mutation of the endopeptidase recognition site (H3 Q19A L20A) and gene induction is defective in these cells. These findings identify clipping of H3 tails as a previously uncharacterized modification of promoter-bound nucleosomes, which may result in the localized clearing of repressive signals during the induction of gene expression.

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Histone H3 Q19L20->AA mutation abrogates tail loss and cause transcription defects.(A) The H3 Q19L20->AA yeast strain does not loose H3 tails.Nuclear fractions from wild type and Q19L20->AA H3 yeast strains cultured in glucose to OD600nm: 7 were analyzed by western blot with anti C-terminal H3 antibody. The clipped H3 product is highlighted.(B) Gene induction is defective in the H3 Q19L20->AA yeast strain.RT-PCR analysis was performed on cultures of wild type and Q19L20->AA H3 grown on rich medium to OD600nm: 0.6 and OD600nm: 7, using primers specific to the indicated genes. The histogram bar represent folds induction for each strain and gene, calculated as the ration of [induced mRNA: non induced mRNA].
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Figure 5: Histone H3 Q19L20->AA mutation abrogates tail loss and cause transcription defects.(A) The H3 Q19L20->AA yeast strain does not loose H3 tails.Nuclear fractions from wild type and Q19L20->AA H3 yeast strains cultured in glucose to OD600nm: 7 were analyzed by western blot with anti C-terminal H3 antibody. The clipped H3 product is highlighted.(B) Gene induction is defective in the H3 Q19L20->AA yeast strain.RT-PCR analysis was performed on cultures of wild type and Q19L20->AA H3 grown on rich medium to OD600nm: 0.6 and OD600nm: 7, using primers specific to the indicated genes. The histogram bar represent folds induction for each strain and gene, calculated as the ration of [induced mRNA: non induced mRNA].

Mentions: To test if the H3 tail-loss is important for gene induction we constructed a yeast strain harbouring the mutation in the histone H3 cleavage site (Q19L20->AA H3). Analysis of the nuclear fraction from yeast grown to stationary phase shows the presence of full length and cleaved H3 in the wild type strain while only full length is present in the mutant (Figure 5A). This mutant strain, which is unable to cleave H3 tails, was then tested for changes in the expression of genes activated on stationary phase (HSP26 and HSP12) and sporulation (IME2). Figure 5B shows that the mutant exhibits impaired induction of these genes. In contrast RTG2, a gene which is known not to change transcription under the tested conditions, does not show any difference between WT and mutant strains. These findings suggest that proteolytic cleavage of the H3 tail at gene promoters contributes to proper induction of gene expression.


Histone H3 tail clipping regulates gene expression.

Santos-Rosa H, Kirmizis A, Nelson C, Bartke T, Saksouk N, Cote J, Kouzarides T - Nat. Struct. Mol. Biol. (2008)

Histone H3 Q19L20->AA mutation abrogates tail loss and cause transcription defects.(A) The H3 Q19L20->AA yeast strain does not loose H3 tails.Nuclear fractions from wild type and Q19L20->AA H3 yeast strains cultured in glucose to OD600nm: 7 were analyzed by western blot with anti C-terminal H3 antibody. The clipped H3 product is highlighted.(B) Gene induction is defective in the H3 Q19L20->AA yeast strain.RT-PCR analysis was performed on cultures of wild type and Q19L20->AA H3 grown on rich medium to OD600nm: 0.6 and OD600nm: 7, using primers specific to the indicated genes. The histogram bar represent folds induction for each strain and gene, calculated as the ration of [induced mRNA: non induced mRNA].
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Related In: Results  -  Collection

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Figure 5: Histone H3 Q19L20->AA mutation abrogates tail loss and cause transcription defects.(A) The H3 Q19L20->AA yeast strain does not loose H3 tails.Nuclear fractions from wild type and Q19L20->AA H3 yeast strains cultured in glucose to OD600nm: 7 were analyzed by western blot with anti C-terminal H3 antibody. The clipped H3 product is highlighted.(B) Gene induction is defective in the H3 Q19L20->AA yeast strain.RT-PCR analysis was performed on cultures of wild type and Q19L20->AA H3 grown on rich medium to OD600nm: 0.6 and OD600nm: 7, using primers specific to the indicated genes. The histogram bar represent folds induction for each strain and gene, calculated as the ration of [induced mRNA: non induced mRNA].
Mentions: To test if the H3 tail-loss is important for gene induction we constructed a yeast strain harbouring the mutation in the histone H3 cleavage site (Q19L20->AA H3). Analysis of the nuclear fraction from yeast grown to stationary phase shows the presence of full length and cleaved H3 in the wild type strain while only full length is present in the mutant (Figure 5A). This mutant strain, which is unable to cleave H3 tails, was then tested for changes in the expression of genes activated on stationary phase (HSP26 and HSP12) and sporulation (IME2). Figure 5B shows that the mutant exhibits impaired induction of these genes. In contrast RTG2, a gene which is known not to change transcription under the tested conditions, does not show any difference between WT and mutant strains. These findings suggest that proteolytic cleavage of the H3 tail at gene promoters contributes to proper induction of gene expression.

Bottom Line: Induction of gene expression in yeast and human cells involves changes in the histone modifications associated with promoters.A truncated H3 product is not generated in yeast carrying a mutation of the endopeptidase recognition site (H3 Q19A L20A) and gene induction is defective in these cells.These findings identify clipping of H3 tails as a previously uncharacterized modification of promoter-bound nucleosomes, which may result in the localized clearing of repressive signals during the induction of gene expression.

View Article: PubMed Central - PubMed

Affiliation: Gurdon Institute and Department of Pathology, Tennis Court Road, Cambridge CB2 1QN, UK.

ABSTRACT
Induction of gene expression in yeast and human cells involves changes in the histone modifications associated with promoters. Here we identify a histone H3 endopeptidase activity in Saccharomyces cerevisiae that may regulate these events. The endopeptidase cleaves H3 after Ala21, generating a histone that lacks the first 21 residues and shows a preference for H3 tails carrying repressive modifications. In vivo, the H3 N terminus is clipped, specifically within the promoters of genes following the induction of transcription. H3 clipping precedes the process of histone eviction seen when genes become fully active. A truncated H3 product is not generated in yeast carrying a mutation of the endopeptidase recognition site (H3 Q19A L20A) and gene induction is defective in these cells. These findings identify clipping of H3 tails as a previously uncharacterized modification of promoter-bound nucleosomes, which may result in the localized clearing of repressive signals during the induction of gene expression.

Show MeSH
Related in: MedlinePlus