Cells. They showed that FOXA factors have non-sequence-specific, intrinsic binding capacity
Cells. They showed that FOXA factors have non-sequence-specific, intrinsic binding capacity to highly condensed chromatin and are able to expose the underlying DNA. They used the fluorescence recovery after photobleaching (FRAP) technique to demonstrate that FOXA factors may laterally scan along the chromatin and serve as an epigenetic mark to indicate chromatin identity and potential activity. Indeed, the notion that transcription factors themselves can serve as critical epigenetic marks has been lost with the excitement of the histone code hypothesis.Genome Biology 2008, 9:http://genomebiology.com/2008/9/4/Genome Biology 2008,Volume 9, Issue 4, ArticleSanij and Hannan 305.Steve Smale (University of California, Los Angeles, USA) provided a functional support for such WP1066 solubility pioneering transcription factors in the PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28607003 transcriptional activation of tissuespecific genes in differentiating embryonic stem (ES) cells. He reported the presence of selective unmethylated regions in the enhancers of well-defined tissue-specific genes that are maintained as unmethylated in ES cells owing to the binding of specific pioneering transcription factors. Erasure of these enhancer marks in differentiated cells led to assembly of repressive chromatin structures that were resistant to decondensation. The data suggest that these enhancer marks in ES cells are important for subsequent transcriptional activation of genes in differentiated tissues. Continuing with the theme of regulatory changes in the composition of chromatin, Robert Kingston (Harvard Medical School, Boston, USA) described a new technology for isolating locus-specific chromatin and associated interacting proteins. He has used a modified fluorescent in situ hybridization protocol to isolate human telomere-specific chromatin. He and his colleagues compared telomeres from HeLa cells with those from cancer cells that employ alternative lengthening of telomeres (ALT) and discovered a family of orphan nuclear receptors that bind specifically to ALT telomeres. Kingston reported that the interaction with these proteins is required for mediating the recombination needed to maintain ALT telomeres.cancer so far. From the expression data they were able to identify four molecular subtypes of high-grade serous and endometrial cancer, as well as two smaller invasive subtypes reflective of borderline serous and low-grade endometriod cancers. They are currently investigating mutations that drive the development and growth of ovarian tumor subtypes.Regulatory networks, nuclear organization and epigenetic reprogrammingCharacterization of transcription factor-DNA interactions into regulatory networks is important for understanding differential regulation of gene expression. Marian Walhout (University of Massachusetts Medical School, Worcester, USA) presented a systematic approach to identifying transcription factor-DNA and factor-factor interactions and incorporated them into regulatory networks using freely available Web-based packages. She used a modified yeast one-hybrid assay to identify transcription factor-DNA interactions between Caenorhabditis elegans gene promoters and transcription factors, and the networks that connect them. Conversely, Sean Grimmond (University of Queensland, Australia) and colleagues reported a novel way to map regulatory networks by surveying the transcriptional output in a model system of ES cell differentiation. They used transcript shotgun, cap analysis gene expression (CAGE) and small RNA.
