Fanconi anemia a is a nucleocytoplasmic shuttling molecule required for gonadotropin-releasing hormone (GnRH) transduction of the GnRH receptor
ENDOCRINOLOGY
Authors: Larder, Rachel; Karali, Dimitra; Nelson, Nancy; Brown, Pamela
Abstract
GnRH binds its cognate G protein-coupled GnRH receptor (GnRHR)located on pituitary gonadotropes and drives expression of gonadotropin hormones. There are two gonadotropin hormones, comprised of a common alpha- and hormone-specific beta-subunit, which are required for gonadal function. Recently we identified that Fanconi anemia a (Fanca), a DNA damage repair gene, is differentially expressed within the L beta T2 gonadotrope cell line in response to stimulation with GnRH. FANCA is mutated in more than 60% of cases of Fanconi anemia ( FA), a rare genetically heterogeneous autosomal recessive disorder characterized by bone marrow failure, endocrine tissue cancer susceptibility, and infertility. Here we show that induction of FANCA protein is mediated by the GnRHR and that the protein constitutively adopts a nucleocytoplasmic intracellular distribution pattern. Using inhibitors to block nuclear import and export and a GnRHR antagonist, we demonstrated that GnRH induces nuclear accumulation of FANCA and green fluorescent protein (GFP)FANCA before exporting back to the cytoplasm using the nuclear export receptor CRM1. Using FANCA point mutations that locate GFP-FANCA to the cytoplasm (H1110P) or functionally uncouple GFP-FANCA (Q1128E) from the wild-type nucleocytoplasmic distribution pattern, we demonstrated that wild-type FANCA was required for GnRH-induced activation of gonadotrope cell markers. Cotransfection of H1110P and Q1128E blocked GnRH activation of the alpha Gsu and GnRHR but not the beta-subunit gene promoters. We conclude that nucleocytoplasmic shuttling of FANCA is required for GnRH transduction of the alpha GSU and GnRHR gene promoters and propose that FANCA functions as a GnRH-induced signal transducer.
The First Case of a Patient with De Novo Partial Distal 16q Tetrasomy and a Data's Review
AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Authors: Kucharczyk, Marzena; Kochanski, Andrzej; Jezela-Stanek, Aleksandra; Kugaudo, Monika; Sielska-Rotblum, Danuta; Gutkowska, Anna; Krajewska-Walasek, Malgorzata
Abstract
We report on a patient with severe psychomotor disability, numerous dysmorphic features, and congenital malformations resulting from a complex genomic rearrangement on 16q24.1-q24.3 involving a de novo duplication-triplication pattern. To the best of our knowledge, this is the first reported patient presenting with this aberration within the distal chromosome 16q. We suggest that the clinical phenotype of our patient results from over-dosage of genes mapped to the region with duplication/triplication (five genes: FOXF1, FOXC2, ANKRD11, SPG7 and FANCA seem to play a peculiar role). Detailed molecular characterization and documentation of the complex genomic rearrangement observed in the proband and of the clinical presentation are important for accurate genotype-phenotype correlations in genetic counseling. Delineation of the gene map for the terminal region of chromosome 16q will provide insight into this chromosome 16q24.1-q24.3 contiguous gene duplication-triplication syndrome. (C) 2014 Wiley Periodicals, Inc.