title: Factor mediated gene priming in pluripotent stem cells sets the stage for lineage specification.
abstract: Priming of lineage-specific genes in pluripotent embryonic stem cells facilitates rapid and coordinated activation of transcriptional programmes during differentiation. There is growing evidence that pluripotency factors play key roles in priming tissue-specific genes and in the earliest stages of lineage commitment. As differentiation progresses, pluripotency factors are replaced at some primed genes by related lineage-specific factors that bind to the same sequences and maintain epigenetic priming until the gene is activated. Polycomb and trithorax group proteins bind many genes in pluripotent cells generating bivalent domains that contain both active and repressive histone modifications. The properties of polycomb proteins suggest that they act as gatekeepers, helping to maintain silencing in pluripotent stem cells while establishing a chromatin environment that is permissive for priming by sequence-specific factors. The overall effect of factor-mediated priming is to initiate the input of information required for cell differentiation before the first lineage choices have been made.
authors.affiliation: Gene Regulation and Chromatin Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London, UK. niall.dillon@csc.mrc.ac.uk
authors.forename: Niall
authors.initials: N
authors.lastname: Dillon
mesh_terms: D000818:Animals; D001665:Binding Sites; D002454:Cell Differentiation; D019070:Cell Lineage; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology*; D005786:Gene Expression Regulation; D006801:Humans; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D063146:Polycomb-Group Proteins; D011485:Protein Binding; D021381:Protein Transport; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D002843:Chromatin; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins; D055748:SOXB1 Transcription Factors