Liver-type fatty acid binding protein interacts with hepatocyte nuclear factor 4.
Additional Document Info
Hepatocyte nuclear factor 4 (HNF4) regulates liver type fatty acid binding protein (L-FABP) gene expression. Conversely as shown herein, L-FABP structurally and functionally also interacts with HNF4. Fluorescence resonance energy transfer (FRET) between Cy3-HNF4 (donor) and Cy5-L-FABP (acceptor) as well as FRET microscopy detected L-FABP in close proximity (~80 ) to HNF4, binding with high affinity Kd ~250-300 nM. Circular dichroism (CD) determined that the HNF4/L-FABP interaction altered protein secondary structure. Finally, L-FABP potentiated transactivation of HNF4 in COS7 cells. Taken together, these data suggest that L-FABP provides a signaling path to HNF4 activation in the nucleus.