The nuclear factor-Y (NF-Y), a trimeric, CCAAT-binding transcriptional activator with histone-like subunits, was until recently considered a prototypical promoter transcription factor. However, recent in vivo chromatin immunoprecipitation assays associated with microarray methodologies (chromatin immunoprecipitation on chip experiments) have indicated that a large portion of target sites (40%-50%) are located outside of core promoters. We applied the tethered particle motion technique to the major histocompatibility complex class II enhancer-promoter region to characterize i), the progressive compaction of DNA due to increasing concentrations of NF-Y, ii), the role of specific subunits and domains of NF-Y in the process, and iii), the interplay between NF-Y and the regulatory factor-X, which cooperatively binds to the X-box adjacent to the CCAAT box. Our study shows that NF-Y has histone-like activity, since it binds DNA nonspeci. cally with high affinity to compact it. This activity, which depends on the presence of all trimer subunits and of their glutamine-rich domains, seems to be attenuated by the transcriptional cofactor regulatory factor-X. Most importantly NF-Y-induced DNA compaction may facilitate promoter-enhancer interactions, which are known to be critical for expression regulation.
|Titolo:||DNA compaction by the nuclear factor Y (NF-Y)|
|Parole Chiave:||factor nf-y ; transcription factor ; cbf/nf-y ; binding ; complex ; promoter ; activation ; chromatin ; domains ; rfx|
|Settore Scientifico Disciplinare:||Settore BIO/18 - Genetica|
|Data di pubblicazione:||lug-2007|
|Digital Object Identifier (DOI):||10.1529/biophysj.106.099929|
|Appare nelle tipologie:||01 - Articolo su periodico|