Project description:HNF4a has been shown to be a central regulator of hepatocyte differentiation and function in adult mice. It was recently shown the HNF4a regulates the onset of hepatic gene expression during liver differentiation in vitro and is critical for the specification of liver towards a hepatic fate We examined the global gene expression of the differentiaiton of iPS cells into specified hepatic cells on consecutive days of liver differentiation (Mallanna et al 2013) to determine the onset of hepatic gene expression and the role HNF4a plays during hepatic specification.
Project description:We observed gene expression changes in livers of cold exposed mice along with changes in global genome occupancy for the transcription factor HNF4a, RNA polymerase II and the histone marker H3K27Ac, suggesting a hepatic transcriptional response to cold xposure.
Project description:The nuclear receptor HNF4A regulates embryonic and post-natal hepatocyte gene expression. Using hepatocyte-specific inactivation in mice, we show that the TAF4 subunit of TFIID acts as a cofactor for HNF4A in vivo and that HNF4A interacts directly with the TAF4-TAF12 heterodimer in vitro. In vivo, TAF4 is required to maintain HNF4A-directed embryonic gene expression at post-natal stages and for HNF4A-directed activation of post-natal gene expression. TAF4 promotes HNF4A occupancy of functional cis-regulatory elements located adjacent to the transcription start sites of post-natal expressed genes and for pre-initiation complex formation required for their expression. Promoter-proximal HNF4A-TFIID interactions are therefore required for pre-initiation complex formation and stable HNF4A occupancy of regulatory elements as two concomitant mutually dependent processes. Examination of PIC, H3k4me3, Ctcf and Hnf4a occupancy in wild-type and Taf4-/- livers by deep sequencing
Project description:The nuclear receptor HNF4A regulates embryonic and post-natal hepatocyte gene expression. Using hepatocyte-specific inactivation in mice, we show that the TAF4 subunit of TFIID acts as a cofactor for HNF4A in vivo and that HNF4A interacts directly with the TAF4-TAF12 heterodimer in vitro. In vivo, TAF4 is required to maintain HNF4A-directed embryonic gene expression at post-natal stages and for HNF4A-directed activation of post-natal gene expression. TAF4 promotes HNF4A occupancy of functional cis-regulatory elements located adjacent to the transcription start sites of post-natal expressed genes and for pre-initiation complex formation required for their expression. Promoter-proximal HNF4A-TFIID interactions are therefore required for pre-initiation complex formation and stable HNF4A occupancy of regulatory elements as two concomitant mutually dependent processes. RNA profiles in wild-type and Taf4-/- livers by deep sequencing
Project description:To determine the downstream regulatory network of HNF4A and HNF1A, two transcription factors that play important roles in the pancreas and liver and that are associated with diabetes, we generated a comprehensive genome-wide map of the binding targets of HNF4A and HNF1A in hiPSC-derived pancreatic and hepatic cells and relevant cell lines using ChIP-Seq and molecular validation. We report binding targets of HNF4A and HNF1A that map to both known and novel gene promoters, that are common or differentially bound across different cell types and developmental stages. Overall, the detailed characterisation of the regulatory roles of HNF4A and HNF1A in pancreatic beta cells and hepatic cells will potentially shed light on how dysregulation of these factors can contribute to altered tissue development and function, and thus pathogenesis of both monogenic diabetes and T2D.
Project description:The nuclear receptor HNF4A regulates embryonic and post-natal hepatocyte gene expression. Using hepatocyte-specific inactivation in mice, we show that the TAF4 subunit of TFIID acts as a cofactor for HNF4A in vivo and that HNF4A interacts directly with the TAF4-TAF12 heterodimer in vitro. In vivo, TAF4 is required to maintain HNF4A-directed embryonic gene expression at post-natal stages and for HNF4A-directed activation of post-natal gene expression. TAF4 promotes HNF4A occupancy of functional cis-regulatory elements located adjacent to the transcription start sites of post-natal expressed genes and for pre-initiation complex formation required for their expression. Promoter-proximal HNF4A-TFIID interactions are therefore required for pre-initiation complex formation and stable HNF4A occupancy of regulatory elements as two concomitant mutually dependent processes.
Project description:The nuclear receptor HNF4A regulates embryonic and post-natal hepatocyte gene expression. Using hepatocyte-specific inactivation in mice, we show that the TAF4 subunit of TFIID acts as a cofactor for HNF4A in vivo and that HNF4A interacts directly with the TAF4-TAF12 heterodimer in vitro. In vivo, TAF4 is required to maintain HNF4A-directed embryonic gene expression at post-natal stages and for HNF4A-directed activation of post-natal gene expression. TAF4 promotes HNF4A occupancy of functional cis-regulatory elements located adjacent to the transcription start sites of post-natal expressed genes and for pre-initiation complex formation required for their expression. Promoter-proximal HNF4A-TFIID interactions are therefore required for pre-initiation complex formation and stable HNF4A occupancy of regulatory elements as two concomitant mutually dependent processes.
Project description:To determine the ability of HNF4A and GATA6 to drive open chromatin formation, either HNF4A or GATA6 were overexpressed in normal oesophageal Het1A cells and ATAC-seq was performed.