5. HNF4α isoforms and their interacting proteins
As for other nuclear receptors, HNF4α is recruited on binding response elements of its target genes. It interacts via its AF-1 and AF-2 domains with coactivating and corepressor protein complexes to regulate transcription (Figure 2). It is well accepted that the presence of AF-1 and or AF-2 domains in HNF4α isoforms can widely impact the physical interaction between these isoforms and other proteins [42, 51, 52]. This could mechanistically explain how these specific isoforms can differentially regulate gene expression in various tissues and developmental stages [53, 54]. However, few studies have deeply characterized these interactions at the molecular and biological levels. Therefore, the following sections highlight some of these interactions in the context of specific HNF4α isoforms.