Protein Phosphatase 2A Activity Affects Histone H3 Phosphorylation and Transcription in Drosophila melanogaster
AUTOR(ES)
Nowak, Scott J.
FONTE
American Society for Microbiology
RESUMO
Transcriptional activation of the heat shock genes during the heat shock response in Drosophila has been intimately linked to phosphorylation of histone H3 at serine 10, whereas repression of non-heat-shock genes correlates with dephosphorylation of histone H3. It is then possible that specific kinase and/or phosphatase activities may regulate histone phosphorylation and therefore transcription activation and repression, respectively. We find that treatment of cells with strong phosphatase inhibitors interferes with the genome-wide dephosphorylation of histone H3 normally observed at non-heat-shock genes during heat shock. Mutants in protein phosphatase type 2A (PP2A) also display reduced genome-wide H3 dephosphorylation, and sites of H3 phosphorylation that do not contain heat shock genes remain transcriptionally active during heat shock in PP2A mutants. Finally, the SET protein, a potent and highly selective inhibitor of PP2A activity that inhibits PP2A-mediated dephosphorylation of Ser10-phosphorylated H3, is detected at transcriptionally active regions of polytene chromosomes. These results suggest that activation and repression of gene expression during heat shock might be regulated by changes in PP2A activity controlled by the SET protein.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=180939Documentos Relacionados
- Polyadenylated H3 histone transcripts and H3 histone variants in alfalfa.
- Drosophila Ada2b Is Required for Viability and Normal Histone H3 Acetylation
- Chromosome condensation induced by fostriecin does not require p34cdc2 kinase activity and histone H1 hyperphosphorylation, but is associated with enhanced histone H2A and H3 phosphorylation.
- Phosphorylation of histone H3 correlates with transcriptionally active loci
- B56-Associated Protein Phosphatase 2A Is Required For Survival and Protects from Apoptosis in Drosophila melanogaster