X-linked adrenal hypoplasia congenita is caused by abnormal nuclear localization of the DAX-1 protein.
Mutations in the DAX-1 [dosage-sensitive sex reversal-adrenal hypoplasia congenita (AHC) critical region on the X chromosome; NR0B1] gene cause X-linked AHC associated with hypogonadotropic hypogonadism. DAX-1 encodes an unusual orphan member of the nuclear hormone receptor superfamily, acting as a transcriptional repressor of genes involved in the steroidogenic pathway. All DAX-1 mutations found in AHC patients alter the protein C terminus, which shares similarity to the ligand binding domain of nuclear hormone receptors and bears transcriptional repressor activity. This property is invariably impaired in DAX-1 AHC mutants. Here we show that the localization of DAX-1 AHC mutant proteins is drastically shifted toward the cytoplasm, even if their nuclear localization signal, which resides in the N terminal of the protein, is intact. Cytoplasmic localization of DAX-1 AHC mutants correlates with an impairment in their transcriptional repression activity. These results reveal a critical role of an intact C terminus in determining DAX-1 subcellular localization and constitute an important example of a defect in human organogenesis caused by impaired nuclear localization of a transcription factor.
Lehmann
Sylvia G
SG
Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Louis Pasteur, B.P. 10142, 67404 Illkirch, Strasbourg, France.
Lalli
Enzo
E
Sassone-Corsi
Paolo
P
D000309:Adrenal Insufficiency / Q000151:congenital / Q000235:genetics*; D000818:Animals; D019556:COS Cells; D002467:Cell Nucleus / Q000235:genetics / Q000502:physiology*; D002522:Chlorocebus aethiops; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D016133:Polymerase Chain Reaction; D018168:Receptors, Retinoic Acid / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014960:X Chromosome
D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; C539965:NR0B1 protein, human; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins; D014157:Transcription Factors