Beschreibung:
<jats:p>Hepatocyte nuclear factor 4α (HNF4α) regulates liver type fatty acid binding protein (L‐FABP) gene expression. Conversely as shown herein, L‐FABP structurally and functionally also interacts with HNF4α. Fluorescence resonance energy transfer (FRET) between Cy3‐HNF4α (donor) and Cy5‐L‐FABP (acceptor) as well as FRET microscopy detected L‐FABP in close proximity (∼80 Å) to HNF4α, binding with high affinity <jats:italic>K<jats:sub>d</jats:sub>
</jats:italic> ∼250–300 nM. Circular dichroism (CD) determined that the HNF4α/L‐FABP interaction altered protein secondary structure. Finally, L‐FABP potentiated transactivation of HNF4α in COS7 cells. Taken together, these data suggest that L‐FABP provides a signaling path to HNF4α activation in the nucleus.</jats:p>