Maturity-onset diabetes of the young type 3 (MODY3) results from mutations in the transcriptional activator hepatocyte nuclear factor-1alpha (HNF-1alpha). Several MODY3 mutations target the HNF-1alpha dimerization domain (HNF-p1), which binds the coactivator, dimerization cofactor of HNF-1 (DCoH) ...
Maturity-onset diabetes of the young type 3 (MODY3) results from mutations in the transcriptional activator hepatocyte nuclear factor-1alpha (HNF-1alpha). Several MODY3 mutations target the HNF-1alpha dimerization domain (HNF-p1), which binds the coactivator, dimerization cofactor of HNF-1 (DCoH). To define the mechanism of coactivator recognition and the basis for the MODY3 phenotype, we determined the cocrystal structure of the DCoH-HNF-p1 complex and characterized biochemically the effects of MODY3 mutations in HNF-p1. The DCoH-HNF-p1 complex comprises a dimer of dimers in which HNF-p1 forms a unique four-helix bundle. Through rearrangements of interfacial side chains, a single, bifunctional interface in the DCoH dimer mediates both HNF-1alpha binding and formation of a competing, transcriptionally inactive DCoH homotetramer. Consistent with the structure, MODY3 mutations in HNF-p1 reduce activator function by two distinct mechanisms.
Related Citations:
Crystal structure of DCoH, a bifunctional, protein-binding transcriptional coactivator Endrizzi, J.A., Cronk, J.D., Weidong, W., Crabtree, G.R., Alber, T. (1995) Science 268: 556
High-resolution structures of the bifunctional enzyme and transcriptional coactivator DCoH and its complex with a product analogue Cronk, J.D., Endrizzi, J.A., Alber, T. (1996) Protein Sci 5: 1963
Organizational Affiliation:
Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3206, USA.
Download Mendeley
