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Aflorei ED, Klapholz B, Chen C, Radian S, Dragu AN, Moderau N, Prodromou C, Ribeiro PS, Stanewsky R, Korbonits M. In vivo bioassay to test the pathogenicity of missense human AIP variants. J Med Genet 2018; 55:522-529. [PMID: 29632148 PMCID: PMC6073908 DOI: 10.1136/jmedgenet-2017-105191] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/23/2018] [Accepted: 03/01/2018] [Indexed: 12/17/2022]
Abstract
Background Heterozygous germline loss-of-function mutations in the aryl hydrocarbon receptor-interacting protein gene (AIP) predispose to childhood-onset pituitary tumours. The pathogenicity of missense variants may pose difficulties for genetic counselling and family follow-up. Objective To develop an in vivo system to test the pathogenicity of human AIP mutations using the fruit fly Drosophila melanogaster. Methods We generated a null mutant of the Drosophila AIP orthologue, CG1847, a gene located on the Xchromosome, which displayed lethality at larval stage in hemizygous knockout male mutants (CG1847exon1_3). We tested human missense variants of ‘unknown significance’, with ‘pathogenic’ variants as positive control. Results We found that human AIP can functionally substitute for CG1847, as heterologous overexpression of human AIP rescued male CG1847exon1_3 lethality, while a truncated version of AIP did not restore viability. Flies harbouring patient-specific missense AIP variants (p.C238Y, p.I13N, p.W73R and p.G272D) failed to rescue CG1847exon1_3 mutants, while seven variants (p.R16H, p.Q164R, p.E293V, p.A299V, p.R304Q, p.R314W and p.R325Q) showed rescue, supporting a non-pathogenic role for these latter variants corresponding to prevalence and clinical data. Conclusion Our in vivo model represents a valuable tool to characterise putative disease-causing human AIP variants and assist the genetic counselling and management of families carrying AIP variants.
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Affiliation(s)
- Elena Daniela Aflorei
- Centre for Endocrinology, Barts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Benjamin Klapholz
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Chenghao Chen
- Department of Cell and Developmental Biology, Division of Biosciences, Faculty of Life Sciences, University College London, London, UK
| | - Serban Radian
- Centre for Endocrinology, Barts and the London School of Medicine, Queen Mary University of London, London, UK.,Department of Endocrinology, C.I. Parhon National Institute of Endocrinology, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Anca Neluta Dragu
- Centre for Endocrinology, Barts and the London School of Medicine, Queen Mary University of London, London, UK.,Department of Cell and Developmental Biology, Division of Biosciences, Faculty of Life Sciences, University College London, London, UK
| | - Nina Moderau
- Protein Dynamics and Cell Signalling Laboratory, Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | | | - Paulo S Ribeiro
- Protein Dynamics and Cell Signalling Laboratory, Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Ralf Stanewsky
- Department of Cell and Developmental Biology, Division of Biosciences, Faculty of Life Sciences, University College London, London, UK.,Institute of Neuro- and Behavioural Biology, Westfälische Wilhelms University, Münster, Germany
| | - Márta Korbonits
- Centre for Endocrinology, Barts and the London School of Medicine, Queen Mary University of London, London, UK
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Spring-Pearson SM, Stone JK, Doyle A, Allender CJ, Okinaka RT, Mayo M, Broomall SM, Hill JM, Karavis MA, Hubbard KS, Insalaco JM, McNew LA, Rosenzweig CN, Gibbons HS, Currie BJ, Wagner DM, Keim P, Tuanyok A. Pangenome Analysis of Burkholderia pseudomallei: Genome Evolution Preserves Gene Order despite High Recombination Rates. PLoS One 2015; 10:e0140274. [PMID: 26484663 PMCID: PMC4613141 DOI: 10.1371/journal.pone.0140274] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 09/23/2015] [Indexed: 11/19/2022] Open
Abstract
The pangenomic diversity in Burkholderia pseudomallei is high, with approximately 5.8% of the genome consisting of genomic islands. Genomic islands are known hotspots for recombination driven primarily by site-specific recombination associated with tRNAs. However, recombination rates in other portions of the genome are also high, a feature we expected to disrupt gene order. We analyzed the pangenome of 37 isolates of B. pseudomallei and demonstrate that the pangenome is ‘open’, with approximately 136 new genes identified with each new genome sequenced, and that the global core genome consists of 4568±16 homologs. Genes associated with metabolism were statistically overrepresented in the core genome, and genes associated with mobile elements, disease, and motility were primarily associated with accessory portions of the pangenome. The frequency distribution of genes present in between 1 and 37 of the genomes analyzed matches well with a model of genome evolution in which 96% of the genome has very low recombination rates but 4% of the genome recombines readily. Using homologous genes among pairs of genomes, we found that gene order was highly conserved among strains, despite the high recombination rates previously observed. High rates of gene transfer and recombination are incompatible with retaining gene order unless these processes are either highly localized to specific sites within the genome, or are characterized by symmetrical gene gain and loss. Our results demonstrate that both processes occur: localized recombination introduces many new genes at relatively few sites, and recombination throughout the genome generates the novel multi-locus sequence types previously observed while preserving gene order.
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Affiliation(s)
- Senanu M. Spring-Pearson
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
| | - Joshua K. Stone
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
| | - Adina Doyle
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
| | - Christopher J. Allender
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
| | - Richard T. Okinaka
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
| | - Mark Mayo
- Menzies School of Health Research and Infectious Disease Department, Royal Darwin Hospital. Darwin, Northern Territory, Australia
| | - Stacey M. Broomall
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - Jessica M. Hill
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - Mark A. Karavis
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - Kyle S. Hubbard
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - Joseph M. Insalaco
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - Lauren A. McNew
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - C. Nicole Rosenzweig
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - Henry S. Gibbons
- BioSciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD, United States of America
| | - Bart J. Currie
- Menzies School of Health Research and Infectious Disease Department, Royal Darwin Hospital. Darwin, Northern Territory, Australia
| | - David M. Wagner
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
| | - Paul Keim
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
- * E-mail:
| | - Apichai Tuanyok
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, United States of America
- Department of Infectious Diseases and Pathology, University of Florida, Gainesville, FL, United States of America
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Abstract
Germline mutations in the aryl hydrocarbon receptor-interacting protein gene (AIP) predispose to young-onset pituitary tumours, most often to GH- or prolactin-secreting adenomas, and most of these patients belong to familial isolated pituitary adenoma families. The molecular pathway initiated by the loss-of-function AIP mutations leading to pituitary tumour formation is unknown. AIP, a co-chaperone of heat-shock protein 90 and various nuclear receptors, belongs to the family of tetratricopeptide repeat (TPR)-containing proteins. It has three antiparallel α-helix motifs (TPR domains) that mediate the interaction of AIP with most of its partners. In this review, we summarise the known interactions of AIP described so far. The identification of AIP partners and the understanding of how AIP interacts with these proteins might help to explain the specific phenotype of the families with heterozygous AIP mutations, to gain deeper insight into the pathological process of pituitary tumour formation and to identify novel drug targets.
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Affiliation(s)
- Giampaolo Trivellin
- Department of Endocrinology, Bart's and the London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
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Cooper DN, Ball EV, Mort M. Chromosomal distribution of disease genes in the human genome. Genet Test Mol Biomarkers 2010; 14:441-6. [PMID: 20642358 DOI: 10.1089/gtmb.2010.0081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Genes are nonrandomly distributed in the human genome, both within and between chromosomes. Thus, genes of similar function and common evolutionary origin are often clustered, as are genes with similar expression profiles. We now report that the >2400 genes known to underlie human monogenic inherited disease are non-randomly distributed in the genome over and above the general nonrandomness evident in the distribution of human genes. Further, a subset of 315 inherited disease genes subject to gross deletion was found to exhibit a degree of clustering that was twice that manifested by disease genes in general. The clustering of human disease genes is likely to have important implications for understanding the genotype-phenotype relationship in contiguous gene syndromes as well as those conditions characterized by multigene deletions or complex chromosomal rearrangements.
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Affiliation(s)
- David N Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom.
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