Total cellular proteome analysis of mutant and WT HNF4alpha Hepatic Progenitor Stage Cells

Post-translational modification of proteins has been shown to control different aspects of protein biology. We have previously implicated a SUMO consensus motif in HNF4alpha’s carboxylic terminus as an important regulator of protein biology during stem cell differentiation. In this study, we have generated deletion and point mutants of HNF4alpha to precisely study the role of protein domains during hepatocyte specification. During mammalian development, liver differentiation is driven by signals which converge on multiple transcription factor networks. The hepatocyte nuclear factor signalling network is known to be essential for hepatocyte specification and maintenance. In these studies we demonstrate that nuclear HNF4 is essential for hepatic progenitor specification and the introduction of point mutations in HNF4alpha’s SUMO consensus motif leads to disrupted hepatocyte specification and maturation. Taking a multi-omics approach, we identified key deficiencies in cell biology which included; dysfunctional cell metabolism, cell adhesion, tricarboxylic acid cycle flux, mRNA transport and processing. In summary, the combination of genome editing and multi-omics analyses have provided new insight into the diverse functions of HNF4alphaprotein during human hepatocyte specification and maturation.