CCAAT/Enhancer-binding Protein α Alters Histone H3 Acetylation at Large Subnuclear Domains

• Published in: The Journal of biological chemistry 2001-11, Vol.276 (44), p.40373
• Main Authors: Wan-Hui Zhang, Roopali Srihari, Richard N. Day, Fred Schaufele
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.C100505200

Transcriptional regulation is commonly associated with local levels of histone acetylation, which controls chromatin structure at specific genes or within contiguous chromosomal domains. Less well understood are the higher order determinants of histone acetylation. The transcription factor, CCAAT/enhancer-binding protein α (C/EBPα), concentrates at one higher order structure, the peri-centromeric chromatin, and regulates differentiation in many cell types, including pituitary cells. We used quantitative fluorescence microscopy to show that immunostained acetylated histone H3 is relatively absent from peri-centromeric domains visible as large structures in mouse pituitary progenitor GHFT1-5 cells. GHFT1-5 cells do not contain C/EBPα. We observed that expression of C/EBPα in GHFT1-5 cells leads to an increased level of acetylated histone H3, but not acetylated histone H4, at the peri-centromeric domains. Only transcriptionally active forms of C/EBPα altered histone acetylation at the peri-centromeric domain. The altered state of histone acetylation at large intranuclear domains may complement, counteract, or supercede the more gene-local activities of other transcription factors to coordinate C/EBPα-induced cellular differentiation.