Project description:We show here by using genome-wide ChIP-sequencing that lineage segregation involves multiple Sox/Oct partnership. In undifferentiated ES cells Oct4 interacts with Sox2 and both TFs bind on the 'canonical' motif, whereas in cells commited to PrE lineage Oct4 switches from Sox2 to Sox17 interaction and this complex bind to a unique "compressed" motif. ChIP-sequencing has been done for Sox2, Sox17 and Oct4 in the pluripotent context or PrE context
Project description:We show here by using genome-wide ChIP-sequencing that lineage segregation involves multiple Sox/Oct partnership. In undifferentiated ES cells Oct4 interacts with Sox2 and both TFs bind on the 'canonical' motif, whereas in cells commited to PrE lineage Oct4 switches from Sox2 to Sox17 interaction and this complex bind to a unique "compressed" motif.
Project description:Embryonic stem cell (ESCs) identity is orchestrated by co-operativity between the transcription factors (TFs) Sox2 and the class V POU-TF, Oct4 at composite Sox/Oct motifs. Neural stem cells (NSCs) lack Oct4 but express Sox2 and class III POU-TFs. This raises the question of how Sox2 interacts with POU-TFs to transcriptionally specify ESCs or NSCs. Here we show that Oct4 alone binds the Sox/Oct motif and the octamer-containing palindromic MORE equally well. Sox2 binding selectively increases the affinity of Oct4 for the Sox/Oct motif. In contrast, Oct6 binds preferentially to the MORE, and is unaffected by Sox2. ChIP-seq in NSCs shows the MORE to be the most enriched motif for class III POU-TFs, with MORE sub-types apparent, but no Sox/Oct motif enrichment. These results suggest that in NSCs, co-operativity between Sox2 and class III POU-TFs may not occur and that POU-TF driven transcription uses predominantly the MORE cis architecture. Thus, distinct interactions between Sox2 and POU-TF subclasses distinguish pluripotent ESCs from multipotent NSCs, providing molecular insight into how Oct4 alone can convert NSCs to pluripotency.
