Dynamically acetylated histone association with transcriptionally active and competent genes in the avian adult beta-globin gene domain.
In chicken immature erythrocytes, class 1 acetylated histones are rapidly tri- and tetra-acetylated and rapidly deacetylated. Class 2 acetylated H3 and H4 are rapidly acetylated to mono- and di-acetylated isoforms and slowly deacetylated. Our previous studies suggested that class 1 acetylated histones were primarily associated with transcriptionally active DNA (beta(A)-globin) but not competent DNA (epsilon-globin). Chromatin salt solubility (chromatin fiber oligomerization) is directly influenced by hyperacetylation. In this study we investigated the association of class 1 histones with beta(A)- and epsilon-globin DNA by measuring their loss of solubility rates in 150 mm NaCl and 3 mm MgCl(2) as a function of hyperacetylated histone deacetylation. Expressed and competent chromatin was associated with class 1 acetylated histones. As most active chromatin and hyperacetylated histones are associated with the low salt-insoluble residual nuclear material containing the nuclear matrix, we investigated whether hyperacetylated histones are bound to the beta(A)- and epsilon-globin DNA in this fraction. In chromatin immunoprecipitation assays, we found that the beta(A)- and epsilon-globin coding regions are bound to hyperacetylated H3 and H4. Our observations are consistent with a model in which nuclear matrix-associated histone acetyltransferases and deacetylases mediate a dynamic attachment between active and competent chromatin and the nuclear matrix.
Spencer
V A
VA
Manitoba Institute of Cell Biology, Winnipeg, Manitoba R3E 0V9, Canada.
Davie
J R
JR
D000107:Acetylation; D000818:Animals; D001483:Base Sequence; D002645:Chickens; D002843:Chromatin / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D005914:Globins / Q000235:genetics*; D006657:Histones / Q000378:metabolism*; D014158:Transcription, Genetic; D014819:Vitellogenins / Q000235:genetics
D002843:Chromatin; D006657:Histones; D014819:Vitellogenins; D005914:Globins; D004247:DNA