Increased Ser-10 phosphorylation of histone H3 in mitogen-stimulated and oncogene-transformed mouse fibroblasts.
When the Ras mitogen-activated protein kinase (MAPK) signaling pathway of quiescent cells is stimulated with growth factors or phorbol esters, the early response genes c-fos and c-myc are rapidly induced, and concurrently there is a rapid phosphorylation of histone H3. Using an antibody specific for phosphorylated Ser-10 of H3, we show that Ser-10 of H3 is phosphorylated, and we provide direct evidence that phosphorylated H3 is associated with c-fos and c-myc genes in stimulated cells. H3 phosphorylation may contribute to proto-oncogene induction by modulating chromatin structure and releasing blocks in elongation. Previously we reported that persistent stimulation of the Ras-MAPK signaling pathway in oncogene-transformed cells resulted in increased amounts of phosphorylated histone H1. Here we show that phosphorylated H3 is elevated in the oncogene-transformed mouse fibroblasts. Further we show that induction of ras expression results in a rapid increase in H3 phosphorylation. H3 phosphatase, identified as PP1, activities in ras-transformed and parental fibroblast cells were similar, suggesting that elevated H3 kinase activity was responsible for the increased level of phosphorylated H3 in the oncogene-transformed cells. Elevated levels of phosphorylated H1 and H3 may be responsible for the less condensed chromatin structure and aberrant gene expression observed in the oncogene-transformed cells.
Chadee
D N
DN
Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Manitoba, R3E 0V9 Canada.
Hendzel
M J
MJ
Tylipski
C P
CP
Allis
C D
CD
Bazett-Jones
D P
DP
Wright
J A
JA
Davie
J R
JR
D016475:3T3 Cells; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D016762:Genes, fos; D016259:Genes, myc; D011905:Genes, ras; D006657:Histones / Q000378:metabolism*; D051379:Mice; D008934:Mitogens / Q000494:pharmacology*; D019319:Okadaic Acid / Q000494:pharmacology; D010766:Phosphorylation; D010768:Phosphoserine / Q000276:immunology / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014170:Transformation, Genetic
D002843:Chromatin; D006657:Histones; D008934:Mitogens; D011518:Proto-Oncogene Proteins; D010768:Phosphoserine; D019319:Okadaic Acid; D004815:Epidermal Growth Factor; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D013755:Tetradecanoylphorbol Acetate