The distribution of somatic H1 subtypes is non-random on active vs. inactive chromatin: distribution in human fetal fibroblasts.
Chromatin immunoprecipitation was employed to determine whether or not the previously reported depletion of histone H1 on actively transcribed sequences was selective with respect to H1 subtypes. DNA of immunofractionated chromatin was analyzed by slot-blots for repetitive sequences and PCR for single and low-copy sequences. Based on the analysis of a diverse set of sequences, we report distinct differences in subtype distributions. Actively transcribed chromatin, as well as chromatin poised for transcription, is characterized by a relative depletion of somatic H1 subtypes 2 and 4 (H1s-2 and H1s-4),whereas facultative and constitutive heterochromatin contain all four somatic subtypes. These results support a model in which subtypes are selectively depleted upon gene expression. In turn, the data also support the possibility that the somatic subtypes have different functional roles based on their selective depletion from different classes of DNA sequences.
Parseghian
M H
MH
Research and Development, Techniclone Corporation, Tustin, CA 92780, USA.
Newcomb
R L
RL
Winokur
S T
ST
Hamkalo
B A
BA
D000199:Actins / Q000235:genetics; D002460:Cell Line; D002843:Chromatin / Q000648:ultrastructure*; D003432:Cross-Linking Reagents / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics; D005347:Fibroblasts / Q000378:metabolism* / Q000648:ultrastructure; D006657:Histones / Q000648:ultrastructure*; D006801:Humans; D007136:Immunoglobulins / Q000235:genetics; D051821:Lymphoid Enhancer-Binding Factor 1; D008957:Models, Genetic; D009419:Nerve Tissue Proteins / Q000235:genetics; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics; D011544:Pseudogenes; D051498:Receptor, Fibroblast Growth Factor, Type 3; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics; D020080:Tandem Repeat Sequences; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic
D000199:Actins; D002843:Chromatin; D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D006657:Histones; C014609:IgK; D007136:Immunoglobulins; D051821:Lymphoid Enhancer-Binding Factor 1; D009419:Nerve Tissue Proteins; D016271:Proto-Oncogene Proteins c-myc; D017468:Receptors, Fibroblast Growth Factor; D014157:Transcription Factors; C033652:postsynaptic density proteins; C496365:FGFR3 protein, human; D011505:Protein-Tyrosine Kinases; D051498:Receptor, Fibroblast Growth Factor, Type 3