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Her Y, Pascual DM, Goldstone-Joubert Z, Marcogliese PC. Variant functional assessment in Drosophila by overexpression: what can we learn? Genome 2024; 67:158-167. [PMID: 38412472 DOI: 10.1139/gen-2023-0135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
The last decade has been highlighted by the increased use of next-generation DNA sequencing technology to identify novel human disease genes. A critical downstream part of this process is assigning function to a candidate gene variant. Functional studies in Drosophila melanogaster, the common fruit fly, have made a prominent contribution in annotating variant impact in an in vivo system. The use of patient-derived knock-in flies or rescue-based, "humanization", approaches are novel and valuable strategies in variant testing but have been recently widely reviewed. An often-overlooked strategy for determining variant impact has been GAL4/upstream activation sequence-mediated tissue-defined overexpression in Drosophila. This mini-review will summarize the recent contribution of ectopic overexpression of human reference and variant cDNA in Drosophila to assess variant function, interpret the consequence of the variant, and in some cases infer biological mechanisms.
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Affiliation(s)
- Yina Her
- Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Children's Hospital Research Institute of Manitoba (CHRIM), University of Manitoba, Winnipeg, MB, Canada
| | - Danielle M Pascual
- Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Children's Hospital Research Institute of Manitoba (CHRIM), University of Manitoba, Winnipeg, MB, Canada
| | - Zoe Goldstone-Joubert
- Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Children's Hospital Research Institute of Manitoba (CHRIM), University of Manitoba, Winnipeg, MB, Canada
| | - Paul C Marcogliese
- Department of Biochemistry and Medical Genetics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Children's Hospital Research Institute of Manitoba (CHRIM), University of Manitoba, Winnipeg, MB, Canada
- Excellence in Neurodevelopment and Rehabilitation Research in Child Health (ENRRICH) Theme, Winnipeg, MB, Canada
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2
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Liao JZ, Chung HL, Shih C, Wong KKL, Dutta D, Nil Z, Burns CG, Kanca O, Park YJ, Zuo Z, Marcogliese PC, Sew K, Bellen HJ, Verheyen EM. Cdk8/CDK19 promotes mitochondrial fission through Drp1 phosphorylation and can phenotypically suppress pink1 deficiency in Drosophila. Nat Commun 2024; 15:3326. [PMID: 38637532 PMCID: PMC11026413 DOI: 10.1038/s41467-024-47623-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 04/08/2024] [Indexed: 04/20/2024] Open
Abstract
Cdk8 in Drosophila is the orthologue of vertebrate CDK8 and CDK19. These proteins have been shown to modulate transcriptional control by RNA polymerase II. We found that neuronal loss of Cdk8 severely reduces fly lifespan and causes bang sensitivity. Remarkably, these defects can be rescued by expression of human CDK19, found in the cytoplasm of neurons, suggesting a non-nuclear function of CDK19/Cdk8. Here we show that Cdk8 plays a critical role in the cytoplasm, with its loss causing elongated mitochondria in both muscles and neurons. We find that endogenous GFP-tagged Cdk8 can be found in both the cytoplasm and nucleus. We show that Cdk8 promotes the phosphorylation of Drp1 at S616, a protein required for mitochondrial fission. Interestingly, Pink1, a mitochondrial kinase implicated in Parkinson's disease, also phosphorylates Drp1 at the same residue. Indeed, overexpression of Cdk8 significantly suppresses the phenotypes observed in flies with low levels of Pink1, including elevated levels of ROS, mitochondrial dysmorphology, and behavioral defects. In summary, we propose that Pink1 and Cdk8 perform similar functions to promote Drp1-mediated fission.
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Affiliation(s)
- Jenny Zhe Liao
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
| | - Hyung-Lok Chung
- Department of Neurology, Houston Methodist Research Institute, Houston, TX, USA
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Claire Shih
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
| | - Kenneth Kin Lam Wong
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Debdeep Dutta
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zelha Nil
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Catherine Grace Burns
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ye-Jin Park
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Paul C Marcogliese
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, R3E0J9, MB, Canada
- Children's Hospital Research Institute of Manitoba, Winnipeg, R3E3P4, MB, Canada
| | - Katherine Sew
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Esther M Verheyen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada.
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada.
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3
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Sultanakhmetov G, Kato I, Asada A, Saito T, Ando K. Microtubule-affinity regulating kinase family members distinctively affect tau phosphorylation and promote its toxicity in a Drosophila model. Genes Cells 2024; 29:337-346. [PMID: 38329182 DOI: 10.1111/gtc.13101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/09/2024]
Abstract
Accumulation of abnormally phosphorylated tau and its aggregation constitute a significant hallmark of Alzheimer's disease (AD). Tau phosphorylation at Ser262 and Ser356 in the KXGS motifs of microtubule-binding repeats plays a critical role in its physiological function and AD disease progression. Major tau kinases to phosphorylate tau at Ser262 and Ser356 belong to the Microtubule Affinity Regulating Kinase family (MARK1-4), which are considered one of the major contributors to tau abnormalities in AD. However, whether and how each member affects tau toxicity in vivo is unclear. We used transgenic Drosophila as a model to compare the effect on tau-induced neurodegeneration among MARKs in vivo. MARK4 specifically promotes tau accumulation and Ser396 phosphorylation, which yields more tau toxicity than was caused by other MARKs. Interestingly, MARK1, 2, and 4 increased tau phosphorylation at Ser262 and Ser356, but only MARK4 caused tau accumulation, indicating that these sites alone did not cause pathological tau accumulation. Our results revealed MARKs are different in their effect on tau toxicity, and also in tau phosphorylation at pathological sites other than Ser262 and Ser356. Understanding the implementation of each MARK into neurodegenerative disease helps to develop more target and safety therapies to overcome AD and related tauopathies.
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Affiliation(s)
- Grigorii Sultanakhmetov
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Iori Kato
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Akiko Asada
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
- Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Taro Saito
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
- Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Kanae Ando
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
- Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, Tokyo, Japan
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4
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Yamamoto S, Kanca O, Wangler MF, Bellen HJ. Integrating non-mammalian model organisms in the diagnosis of rare genetic diseases in humans. Nat Rev Genet 2024; 25:46-60. [PMID: 37491400 DOI: 10.1038/s41576-023-00633-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2023] [Indexed: 07/27/2023]
Abstract
Next-generation sequencing technology has rapidly accelerated the discovery of genetic variants of interest in individuals with rare diseases. However, showing that these variants are causative of the disease in question is complex and may require functional studies. Use of non-mammalian model organisms - mainly fruitflies (Drosophila melanogaster), nematode worms (Caenorhabditis elegans) and zebrafish (Danio rerio) - enables the rapid and cost-effective assessment of the effects of gene variants, which can then be validated in mammalian model organisms such as mice and in human cells. By probing mechanisms of gene action and identifying interacting genes and proteins in vivo, recent studies in these non-mammalian model organisms have facilitated the diagnosis of numerous genetic diseases and have enabled the screening and identification of therapeutic options for patients. Studies in non-mammalian model organisms have also shown that the biological processes underlying rare diseases can provide insight into more common mechanisms of disease and the biological functions of genes. Here, we discuss the opportunities afforded by non-mammalian model organisms, focusing on flies, worms and fish, and provide examples of their use in the diagnosis of rare genetic diseases.
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Affiliation(s)
- Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
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5
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Mao K, Borel C, Ansar M, Jolly A, Makrythanasis P, Froehlich C, Iwaszkiewicz J, Wang B, Xu X, Li Q, Blanc X, Zhu H, Chen Q, Jin F, Ankamreddy H, Singh S, Zhang H, Wang X, Chen P, Ranza E, Paracha SA, Shah SF, Guida V, Piceci-Sparascio F, Melis D, Dallapiccola B, Digilio MC, Novelli A, Magliozzi M, Fadda MT, Streff H, Machol K, Lewis RA, Zoete V, Squeo GM, Prontera P, Mancano G, Gori G, Mariani M, Selicorni A, Psoni S, Fryssira H, Douzgou S, Marlin S, Biskup S, De Luca A, Merla G, Zhao S, Cox TC, Groves AK, Lupski JR, Zhang Q, Zhang YB, Antonarakis SE. FOXI3 pathogenic variants cause one form of craniofacial microsomia. Nat Commun 2023; 14:2026. [PMID: 37041148 PMCID: PMC10090152 DOI: 10.1038/s41467-023-37703-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 03/28/2023] [Indexed: 04/13/2023] Open
Abstract
Craniofacial microsomia (CFM; also known as Goldenhar syndrome), is a craniofacial developmental disorder of variable expressivity and severity with a recognizable set of abnormalities. These birth defects are associated with structures derived from the first and second pharyngeal arches, can occur unilaterally and include ear dysplasia, microtia, preauricular tags and pits, facial asymmetry and other malformations. The inheritance pattern is controversial, and the molecular etiology of this syndrome is largely unknown. A total of 670 patients belonging to unrelated pedigrees with European and Chinese ancestry with CFM, are investigated. We identify 18 likely pathogenic variants in 21 probands (3.1%) in FOXI3. Biochemical experiments on transcriptional activity and subcellular localization of the likely pathogenic FOXI3 variants, and knock-in mouse studies strongly support the involvement of FOXI3 in CFM. Our findings indicate autosomal dominant inheritance with reduced penetrance, and/or autosomal recessive inheritance. The phenotypic expression of the FOXI3 variants is variable. The penetrance of the likely pathogenic variants in the seemingly dominant form is reduced, since a considerable number of such variants in affected individuals were inherited from non-affected parents. Here we provide suggestive evidence that common variation in the FOXI3 allele in trans with the pathogenic variant could modify the phenotypic severity and accounts for the incomplete penetrance.
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Affiliation(s)
- Ke Mao
- School of Engineering Medicine, Beihang University, Beijing, 100191, China
| | - Christelle Borel
- Department of Genetic Medicine and Development, University of Geneva Medical Faculty, Geneva, 1211, Switzerland
| | - Muhammad Ansar
- Department of Genetic Medicine and Development, University of Geneva Medical Faculty, Geneva, 1211, Switzerland
- Jules-Gonin Eye Hospital, Department of Ophthalmology, University of Lausanne, 1004, Lausanne, Switzerland
| | - Angad Jolly
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Periklis Makrythanasis
- Department of Genetic Medicine and Development, University of Geneva Medical Faculty, Geneva, 1211, Switzerland
- Laboratory of Medical Genetics, Medical School, University of Athens, Athens, Greece
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | | | - Justyna Iwaszkiewicz
- Molecular Modeling Group, Swiss Institute of Bioinformatics, Lausanne, 1015, Switzerland
| | - Bingqing Wang
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences, Beijing, 100144, China
| | - Xiaopeng Xu
- School of Engineering Medicine, Beihang University, Beijing, 100191, China
- Key Laboratory of Big Data-Based Precision Medicine (Beihang University), Ministry of Industry and Information Technology, Beijing, China
| | - Qiang Li
- Department of Plastic Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221000, China
| | - Xavier Blanc
- Medigenome, Swiss Institute of Genomic Medicine, 1207, Geneva, Switzerland
| | - Hao Zhu
- School of Engineering Medicine, Beihang University, Beijing, 100191, China
| | - Qi Chen
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences, Beijing, 100144, China
| | - Fujun Jin
- School of Engineering Medicine, Beihang University, Beijing, 100191, China
- Key Laboratory of Big Data-Based Precision Medicine (Beihang University), Ministry of Industry and Information Technology, Beijing, China
| | - Harinarayana Ankamreddy
- Department of Biotechnology, School of Bioengineering, SRMIST, Kattankulathur, Tamilnadu, 603203, India
| | - Sunita Singh
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Hongyuan Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Xiaogang Wang
- School of Engineering Medicine, Beihang University, Beijing, 100191, China
- Key Laboratory of Big Data-Based Precision Medicine (Beihang University), Ministry of Industry and Information Technology, Beijing, China
| | - Peiwei Chen
- Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Emmanuelle Ranza
- Medigenome, Swiss Institute of Genomic Medicine, 1207, Geneva, Switzerland
| | - Sohail Aziz Paracha
- Anatomy Department, Khyber Medical University Institute of Medical Sciences (KIMS), Kohat, Pakistan
| | - Syed Fahim Shah
- Department of Medicine, KMU Institute of Medical Sciences (KIMS), DHQ Hospital KDA, Kohat, Pakistan
| | - Valentina Guida
- Medical Genetics Division, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | | | - Daniela Melis
- Department of Medicine, Surgery, and Dentistry, Università University degli of Studi di Salerno, Salerno, Italy
| | - Bruno Dallapiccola
- Medical Genetics and Rare Disease Research Division, Pediatric Cardiology, Medical Genetics Laboratory, Neuropsychiatry, Scientific Rectorate, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | | | - Antonio Novelli
- Sezione di Genetica Medica, Ospedale 'Bambino Gesù', Rome, Italy
| | - Monia Magliozzi
- Sezione di Genetica Medica, Ospedale 'Bambino Gesù', Rome, Italy
| | - Maria Teresa Fadda
- Department of Maxillo-Facial Surgery, Policlinico Umberto I, Rome, Italy
| | - Haley Streff
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Keren Machol
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Richard A Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Vincent Zoete
- Molecular Modeling Group, Swiss Institute of Bioinformatics, Lausanne, 1015, Switzerland
- Department of Fundamental Oncology, Ludwig Institute for Cancer Research, Lausanne University, Epalinges, 1066, Switzerland
| | - Gabriella Maria Squeo
- Laboratory of Regulatory & Functional Genomics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Paolo Prontera
- Medical Genetics Unit, Hospital Santa Maria della Misericordia, Perugia, Italy
| | - Giorgia Mancano
- Medical Genetics Unit, University of Perugia Hospital SM della Misericordia, Perugia, Italy
| | - Giulia Gori
- Medical Genetics Unit, Meyer Children's University Hospital, Florence, Italy
| | - Milena Mariani
- Pediatric Department, ASST Lariana, Santa Anna General Hospital, Como, Italy
| | - Angelo Selicorni
- Pediatric Department, ASST Lariana, Santa Anna General Hospital, Como, Italy
| | - Stavroula Psoni
- Laboratory of Medical Genetics, Medical School, University of Athens, Athens, Greece
| | - Helen Fryssira
- Laboratory of Medical Genetics, Medical School, University of Athens, Athens, Greece
| | - Sofia Douzgou
- Division of Evolution, Infection and Genomics, School of Biological Sciences, University of Manchester, Manchester, UK
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Sandrine Marlin
- Centre de Référence Surdités Génétiques, Hôpital Necker, Institut Imagine, Paris, France
| | - Saskia Biskup
- CeGaT GmbH and Praxis für Humangenetik Tuebingen, Tuebingen, 72076, Germany
| | - Alessandro De Luca
- Medical Genetics Division, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Giuseppe Merla
- Laboratory of Regulatory & Functional Genomics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131, Naples, Italy
| | - Shouqin Zhao
- Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Timothy C Cox
- Departments of Oral & Craniofacial Sciences and Pediatrics, University of Missouri-Kansas City, Kansas City, MO, 64108, USA
| | - Andrew K Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Qingguo Zhang
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences, Beijing, 100144, China.
| | - Yong-Biao Zhang
- School of Engineering Medicine, Beihang University, Beijing, 100191, China.
- Key Laboratory of Big Data-Based Precision Medicine (Beihang University), Ministry of Industry and Information Technology, Beijing, China.
| | - Stylianos E Antonarakis
- Department of Genetic Medicine and Development, University of Geneva Medical Faculty, Geneva, 1211, Switzerland.
- Medigenome, Swiss Institute of Genomic Medicine, 1207, Geneva, Switzerland.
- iGE3 Institute of Genetics and Genomes in Geneva, Geneva, Switzerland.
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6
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Yang J, Niu H, Pang S, Liu M, Chen F, Li Z, He L, Mo J, Yi H, Xiao J, Huang Y. MARK3 kinase: Regulation and physiologic roles. Cell Signal 2023; 103:110578. [PMID: 36581219 DOI: 10.1016/j.cellsig.2022.110578] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/14/2022] [Accepted: 12/20/2022] [Indexed: 12/27/2022]
Abstract
Microtubule affinity-regulating kinase 3 (MARK3), a member of the MARK family, regulates several essential pathways, including the cell cycle, ciliated cell differentiation, and osteoclast differentiation. It is important to understand the control of their activities as MARK3 contains an N-terminal serine/threonine kinase domain, ubiquitin-associated domain, and C-terminal kinase-associated domain, which perform multiple regulatory functions. These functions include post-translational modification (e.g., phosphorylation) and interaction with scaffolding and other proteins. Differences in the amino acid sequence and domain position result in different three-dimensional protein structures and affect the function of MARK3, which distinguish it from the other MARK family members. Recent data indicate a potential role of MARK3 in several pathological conditions, including congenital blepharophimosis syndrome, osteoporosis, and tumorigenesis. The present review focuses on the physiological and pathological role of MARK3, its regulation, and recent developments in the small molecule inhibitors of the MARK3 signalling cascade.
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Affiliation(s)
- Jingyu Yang
- Surgery of Mammary Gland and Thyroid Gland, the First People's Hospital of Yunnan Province, Panlong Campus, 157 Jinbi Road, Kunming 650032, Yunnan, People's Republic of China
| | - Heng Niu
- Surgery of Mammary Gland and Thyroid Gland, the First People's Hospital of Yunnan Province, Panlong Campus, 157 Jinbi Road, Kunming 650032, Yunnan, People's Republic of China
| | - ShiGui Pang
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Mignlong Liu
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Feng Chen
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Zhaoxin Li
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Lifei He
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Jianmei Mo
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Huijun Yi
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Juanjuan Xiao
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Yingze Huang
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China.
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7
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Rao AR, Nazir A, Imtiaz S, Paracha SA, Waryah YM, Ujjan ID, Anwar I, Iqbal A, Santoni FA, Shah I, Gul K, Baig HMA, Waryah AM, Antonarakis SE, Ansar M. Delineating the Spectrum of Genetic Variants Associated with Bardet-Biedl Syndrome in Consanguineous Pakistani Pedigrees. Genes (Basel) 2023; 14:404. [PMID: 36833331 PMCID: PMC9956862 DOI: 10.3390/genes14020404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 01/29/2023] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
This study aimed to find the molecular basis of Bardet-Biedl syndrome (BBS) in Pakistani consanguineous families. A total of 12 affected families were enrolled. Clinical investigations were performed to access the BBS-associated phenotypes. Whole exome sequencing was conducted on one affected individual from each family. The computational functional analysis predicted the variants' pathogenic effects and modeled the mutated proteins. Whole-exome sequencing revealed 9 pathogenic variants in six genes associated with BBS in 12 families. The BBS6/MKS was the most common BBS causative gene identified in five families (5/12, 41.6%), with one novel (c.1226G>A, p.Gly409Glu) and two reported variants. c.774G>A, Thr259LeuTer21 was the most frequent BBS6/MMKS allele in three families 3/5 (60%). Two variants, c.223C>T, p.Arg75Ter and a novel, c. 252delA, p.Lys85STer39 were detected in the BBS9 gene. A novel 8bp deletion c.387_394delAAATAAAA, p. Asn130GlyfsTer3 was found in BBS3 gene. Three known variants were detected in the BBS1, BBS2, and BBS7 genes. Identification of novel likely pathogenic variants in three genes reaffirms the allelic and genetic heterogeneity of BBS in Pakistani patients. The clinical differences among patients carrying the same pathogenic variant may be due to other factors influencing the phenotype, including variants in other modifier genes.
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Affiliation(s)
- Ali Raza Rao
- Molecular Biology and Genetics Department, Medical Research Center, Liaquat University of Medical and Health Sciences, Jamshoro 76090, Pakistan
| | - Aamir Nazir
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar 25100, Pakistan
| | - Samina Imtiaz
- Department of Genetics, University of Karachi, Karachi 75270, Pakistan
| | - Sohail Aziz Paracha
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar 25100, Pakistan
| | - Yar Muhammad Waryah
- Scientific and Ophthalmic Research Laboratory, Sindh Institute of Ophthalmology and Visual Sciences, Hyderabad 71000, Pakistan
| | - Ikram Din Ujjan
- Department of Pathology, Liaquat University of Medical and Health Sciences, Jamshoro 76090, Pakistan
| | - Ijaz Anwar
- Department of Ophthalmology, University of Lausanne, Jules Gonin Eye Hospital, Fondation Asile Des Aveugles, 1004 Lausanne, Switzerland
| | - Afia Iqbal
- Department of Zoology, Lahore College for Women University, Lahore 54810, Pakistan
| | - Federico A. Santoni
- Department of Genetic Medicine and Development, University of Geneva, 1211 Geneva, Switzerland
- Department of Endocrinology Diabetes and Metabolism, University Hospital of Lausanne, 1011 Lausanne, Switzerland
| | - Inayat Shah
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar 25100, Pakistan
| | - Khitab Gul
- Department of Genetics, University of Karachi, Karachi 75270, Pakistan
- Department of BioSciences, Faculty of Life Science, Mohammad Ali Jinnah University, Karachi 75400, Pakistan
| | - Hafiz Muhammad Azhar Baig
- Department of Ophthalmology, University of Lausanne, Jules Gonin Eye Hospital, Fondation Asile Des Aveugles, 1004 Lausanne, Switzerland
- Department of Biotechnology, Institute of Biochemistry, Biotechnology and Bioinformatics, The Islamia University of Bahawalpur, Bahawalpur 63080, Pakistan
| | - Ali Muhammad Waryah
- Molecular Biology and Genetics Department, Medical Research Center, Liaquat University of Medical and Health Sciences, Jamshoro 76090, Pakistan
| | - Stylianos E. Antonarakis
- Department of Genetic Medicine and Development, University of Geneva, 1211 Geneva, Switzerland
- iGE3 Institute of Genetics and Genomics of Geneva, 1211 Geneva, Switzerland
| | - Muhammad Ansar
- Department of Ophthalmology, University of Lausanne, Jules Gonin Eye Hospital, Fondation Asile Des Aveugles, 1004 Lausanne, Switzerland
- Department of Genetic Medicine and Development, University of Geneva, 1211 Geneva, Switzerland
- Advanced Molecular Genetics and Genomics Disease Research and Treatment Centre, Dow University of Health Sciences, Karachi 74200, Pakistan
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8
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Xu H, Ye X, Yang Y, Yang Y, Sun YH, Mei Y, Xiong S, He K, Xu L, Fang Q, Li F, Ye G, Lu Z. Comparative Genomics Sheds Light on the Convergent Evolution of Miniaturized Wasps. Mol Biol Evol 2021; 38:5539-5554. [PMID: 34515790 PMCID: PMC8662594 DOI: 10.1093/molbev/msab273] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Miniaturization has occurred in many animal lineages, including insects and vertebrates, as a widespread trend during animal evolution. Among Hymenoptera, miniaturization has taken place in some parasitoid wasp lineages independently, and may have contributed to the diversity of species. However, the genomic basis of miniaturization is little understood. Diverged approximately 200 Ma, Telenomus wasps (Platygastroidea) and Trichogramma wasps (Chalcidoidea) have both evolved to a highly reduced body size independently, representing a paradigmatic example of convergent evolution. Here, we report a high-quality chromosomal genome of Telenomus remus, a promising candidate for controlling Spodoptera frugiperda, a notorious pest that has recently caused severe crop damage. The T. remus genome (129 Mb) is characterized by a low density of repetitive sequence and a reduction of intron length, resulting in the shrinkage of genome size. We show that hundreds of genes evolved faster in two miniaturized parasitoids Trichogramma pretiosum and T. remus. Among them, 38 genes exhibit extremely accelerated evolutionary rates in these miniaturized wasps, possessing diverse functions in eye and wing development as well as cell size control. These genes also highlight potential roles in body size regulation. In sum, our analyses uncover a set of genes with accelerated evolutionary rates in Tri. pretiosum and T. remus, which might be responsible for their convergent adaptations to miniaturization, and thus expand our understanding on the evolutionary basis of miniaturization. Additionally, the genome of T. remus represents the first genome resource of superfamily Platygastroidea, and will facilitate future studies of Hymenoptera evolution and pest control.
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Affiliation(s)
- Hongxing Xu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agroproducts, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xinhai Ye
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
- Shanghai Institute for Advanced Study, Zhejiang University, Shanghai, China
- Institute of Artificial Intelligence, College of Computer Science and Technology, Zhejiang University, Hangzhou, China
| | - Yajun Yang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agroproducts, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Yi Yang
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yu H Sun
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Yang Mei
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Shijiao Xiong
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Kang He
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Le Xu
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Qi Fang
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Fei Li
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Gongyin Ye
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Zhongxian Lu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agroproducts, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
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9
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Ansar M, Ebstein F, Özkoç H, Paracha SA, Iwaszkiewicz J, Gesemann M, Zoete V, Ranza E, Santoni FA, Sarwar MT, Ahmed J, Krüger E, Bachmann-Gagescu R, Antonarakis SE. Biallelic variants in PSMB1 encoding the proteasome subunit β6 cause impairment of proteasome function, microcephaly, intellectual disability, developmental delay and short stature. Hum Mol Genet 2021; 29:1132-1143. [PMID: 32129449 DOI: 10.1093/hmg/ddaa032] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/30/2022] Open
Abstract
The molecular cause of the majority of rare autosomal recessive disorders remains unknown. Consanguinity due to extensive homozygosity unravels many recessive phenotypes and facilitates the detection of novel gene-disease links. Here, we report two siblings with phenotypic signs, including intellectual disability (ID), developmental delay and microcephaly from a Pakistani consanguineous family in which we have identified homozygosity for p(Tyr103His) in the PSMB1 gene (Genbank NM_002793) that segregated with the disease phenotype. PSMB1 encodes a β-type proteasome subunit (i.e. β6). Modeling of the p(Tyr103His) variant indicates that this variant weakens the interactions between PSMB1/β6 and PSMA5/α5 proteasome subunits and thus destabilizes the 20S proteasome complex. Biochemical experiments in human SHSY5Y cells revealed that the p(Tyr103His) variant affects both the processing of PSMB1/β6 and its incorporation into proteasome, thus impairing proteasome activity. CRISPR/Cas9 mutagenesis or morpholino knock-down of the single psmb1 zebrafish orthologue resulted in microcephaly, microphthalmia and reduced brain size. Genetic evidence in the family and functional experiments in human cells and zebrafish indicates that PSMB1/β6 pathogenic variants are the cause of a recessive disease with ID, microcephaly and developmental delay due to abnormal proteasome assembly.
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Affiliation(s)
- Muhammad Ansar
- Department of Genetic Medicine and Development, University of Geneva, Geneva 1211, Switzerland
| | - Frédéric Ebstein
- Institut für Medizinische Biochemie und Molekularbiologie, Universitätsmedizin Greifswald, Greifswald 17475, Germany
| | - Hayriye Özkoç
- Institute of Medical Genetics, University of Zurich, Schlieren 8952, Switzerland
| | - Sohail A Paracha
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar 25100, Pakistan
| | - Justyna Iwaszkiewicz
- Molecular Modeling Group, Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland
| | - Matthias Gesemann
- Department of Molecular Life Sciences, University of Zurich, Zurich 8057, Switzerland
| | - Vincent Zoete
- Molecular Modeling Group, Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland.,Department of Fundamental Oncology, Ludwig Institute for Cancer Research, Lausanne University, Epalinges 1066, Switzerland
| | - Emmanuelle Ranza
- Department of Genetic Medicine and Development, University of Geneva, Geneva 1211, Switzerland.,Service of Genetic Medicine, University Hospitals of Geneva, Geneva 1205, Switzerland
| | - Federico A Santoni
- Department of Genetic Medicine and Development, University of Geneva, Geneva 1211, Switzerland.,Department of Endocrinology Diabetes and Metabolism, Lausanne University Hospital, Lausanne 1011, Switzerland
| | - Muhammad T Sarwar
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar 25100, Pakistan
| | - Jawad Ahmed
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar 25100, Pakistan
| | - Elke Krüger
- Institut für Medizinische Biochemie und Molekularbiologie, Universitätsmedizin Greifswald, Greifswald 17475, Germany
| | - Ruxandra Bachmann-Gagescu
- Institute of Medical Genetics, University of Zurich, Schlieren 8952, Switzerland.,Department of Molecular Life Sciences, University of Zurich, Zurich 8057, Switzerland
| | - Stylianos E Antonarakis
- Department of Genetic Medicine and Development, University of Geneva, Geneva 1211, Switzerland.,Service of Genetic Medicine, University Hospitals of Geneva, Geneva 1205, Switzerland.,iGE3 Institute of Genetics and Genomics of Geneva, Geneva 1211, Switzerland
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10
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Antonarakis SE, Holoubek A, Rapti M, Rademaker J, Meylan J, Iwaszkiewicz J, Zoete V, Wilson C, Taylor J, Ansar M, Borel C, Menzel O, Kuželová K, Santoni FA. Dominant monoallelic variant in the PAK2 gene causes Knobloch syndrome type 2. Hum Mol Genet 2021; 31:1-9. [PMID: 33693784 DOI: 10.1093/hmg/ddab026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 01/11/2021] [Accepted: 01/31/2021] [Indexed: 11/12/2022] Open
Abstract
Knobloch syndrome is an autosomal recessive phenotype mainly characterized by retinal detachment and encephalocele caused by biallelic pathogenic variants in the COL18A1 gene. However, there are patients clinically diagnosed as Knobloch syndrome with unknown molecular etiology not linked to COL18A1. We studied an historical pedigree (published in 1998) designated as KNO2 (Knobloch type 2 syndrome with intellectual disability, autistic behavior, retinal degeneration, encephalocele). Whole exome sequencing of the two affected siblings and the normal parents resulted in the identification of a PAK2 non-synonymous substitution p.(Glu435Lys) as a causative variant. The variant was monoallelic and apparently de novo in both siblings indicating a likely germline mosaicism in one of the parents; the mosaicism however could not be observed after deep sequencing of blood parental DNA. PAK2 encodes a member of a small group of serine/threonine kinases; these P21-activating kinases (PAKs) are essential in signal transduction and cellular regulation (cytoskeletal dynamics, cell motility, death and survival signaling, and cell cycle progression). Structural analysis of the PAK2 p.(Glu435Lys) variant which is located in the kinase domain of the protein predicts a possible compromise in the kinase activity. Functional analysis of the p.(Glu435Lys) PAK2 variant in transfected HEK293T cells results in a partial loss of the kinase activity. PAK2 has been previously suggested as an autism related gene. Our results show that PAK2 induced phenotypic spectrum is broad and not fully understood. We conclude that the KNO2 syndrome in the studied family is dominant and caused by a deleterious variant in the PAK2 gene.
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Affiliation(s)
- Stylianos E Antonarakis
- Department of Genetic Medicine and Development, University of Geneva Medical Faculty, Geneva 1211, Switzerland.,iGE3 Institute of Genetics and Genomics of Geneva, Geneva 1211, Switzerland
| | - Ales Holoubek
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Melivoia Rapti
- Department of Endocrinology Diabetes and Metabolism, Lausanne University Hospital, Lausanne 1011, Switzerland
| | - Jesse Rademaker
- Department of Endocrinology Diabetes and Metabolism, Lausanne University Hospital, Lausanne 1011, Switzerland
| | - Jenny Meylan
- Department of Endocrinology Diabetes and Metabolism, Lausanne University Hospital, Lausanne 1011, Switzerland
| | - Justyna Iwaszkiewicz
- Molecular Modeling Group, Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland
| | - Vincent Zoete
- Molecular Modeling Group, Swiss Institute of Bioinformatics, Lausanne 1015, Switzerland.,Department of Fundamental Oncology, Ludwig Institute for Cancer Research, Lausanne University, Epalinges 1066, Switzerland
| | - Callum Wilson
- National Metabolic Service, Starship Children's Hospital, Auckland 1142, New Zealand
| | - Juliet Taylor
- National Metabolic Service, Starship Children's Hospital, Auckland 1142, New Zealand
| | - Muhammad Ansar
- Institute of Molecular and Clinical Ophthalmology, Basel 4031, Switzerland
| | - Christelle Borel
- Department of Genetic Medicine and Development, University of Geneva Medical Faculty, Geneva 1211, Switzerland
| | - Olivier Menzel
- Health 2030 Genome Center, Foundation Campus Biotech Geneva Foundation, Geneva 1202, Switzerland
| | - Kateřina Kuželová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Federico A Santoni
- Department of Endocrinology Diabetes and Metabolism, Lausanne University Hospital, Lausanne 1011, Switzerland.,Faculty of Biology and Medicine, University of Lausanne, Lausanne 1011, Switzerland
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11
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Link N, Bellen HJ. Using Drosophila to drive the diagnosis and understand the mechanisms of rare human diseases. Development 2020; 147:dev191411. [PMID: 32988995 PMCID: PMC7541339 DOI: 10.1242/dev.191411] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Next-generation sequencing has greatly accelerated the discovery of rare human genetic diseases. Nearly 45% of patients have variants associated with known diseases but the unsolved cases remain a conundrum. Moreover, causative mutations can be difficult to pinpoint because variants frequently map to genes with no previous disease associations and, often, only one or a few patients with variants in the same gene are identified. Model organisms, such as Drosophila, can help to identify and characterize these new disease-causing genes. Importantly, Drosophila allow quick and sophisticated genetic manipulations, permit functional testing of human variants, enable the characterization of pathogenic mechanisms and are amenable to drug tests. In this Spotlight, focusing on microcephaly as a case study, we highlight how studies of human genes in Drosophila have aided our understanding of human genetic disorders, allowing the identification of new genes in well-established signaling pathways.
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Affiliation(s)
- Nichole Link
- Howard Hughes Medical Institute, BCM, Houston, TX, 77030, USA
- Department of Molecular and Human Genetics (MHG), BCM, Houston, TX, 77030, USA
- Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
| | - Hugo J Bellen
- Howard Hughes Medical Institute, BCM, Houston, TX, 77030, USA
- Department of Molecular and Human Genetics (MHG), BCM, Houston, TX, 77030, USA
- Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
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12
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Huang Y, Mao X, van Jaarsveld RH, Shu L, Terhal PA, Jia Z, Xi H, Peng Y, Yan H, Yuan S, Li Q, Wang H, Bellen HJ. Variants in CAPZA2, a member of an F-actin capping complex, cause intellectual disability and developmental delay. Hum Mol Genet 2020; 29:1537-1546. [PMID: 32338762 PMCID: PMC7268783 DOI: 10.1093/hmg/ddaa078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/29/2020] [Accepted: 04/20/2020] [Indexed: 11/13/2022] Open
Abstract
The actin cytoskeleton is regulated by many proteins including capping proteins that stabilize actin filaments (F-actin) by inhibiting actin polymerization and depolymerization. Here, we report two pediatric probands who carry damaging heterozygous de novo mutations in CAPZA2 (HGNC: 1490) and exhibit neurological symptoms with shared phenotypes including global motor development delay, speech delay, intellectual disability, hypotonia and a history of seizures. CAPZA2 encodes a subunit of an F-actin-capping protein complex (CapZ). CapZ is an obligate heterodimer consisting of α and β heterodimer conserved from yeast to human. Vertebrate genomes contain three α subunits encoded by three different genes and CAPZA2 encodes the α2 subunit. The single orthologue of CAPZA genes in Drosophila is cpa. Loss of cpa leads to lethality in early development and expression of the human reference; CAPZA2 rescues this lethality. However, the two CAPZA2 variants identified in the probands rescue this lethality at lower efficiency than the reference. Moreover, expression of the CAPZA2 variants affects bristle morphogenesis, a process that requires extensive actin polymerization and bundling during development. Taken together, our findings suggest that variants in CAPZA2 lead to a non-syndromic neurodevelopmental disorder in children.
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Affiliation(s)
- Yan Huang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xiao Mao
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | | | - Li Shu
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | - Paulien A Terhal
- Department of Genetics, University Medical Center Utrecht, Utrecht CX 3584, The Netherlands
| | - Zhengjun Jia
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | - Hui Xi
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | - Ying Peng
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | - Huiming Yan
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | - Shan Yuan
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | - Qibin Li
- Clabee Genomics, Shenzhen, Guangdong 518000, China
- Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Hua Wang
- National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, China
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, Hunan 410008, China
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
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13
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Chung HL, Wangler MF, Marcogliese PC, Jo J, Ravenscroft TA, Zuo Z, Duraine L, Sadeghzadeh S, Li-Kroeger D, Schmidt RE, Pestronk A, Rosenfeld JA, Burrage L, Herndon MJ, Chen S, Shillington A, Vawter-Lee M, Hopkin R, Rodriguez-Smith J, Henrickson M, Lee B, Moser AB, Jones RO, Watkins P, Yoo T, Mar S, Choi M, Bucelli RC, Yamamoto S, Lee HK, Prada CE, Chae JH, Vogel TP, Bellen HJ. Loss- or Gain-of-Function Mutations in ACOX1 Cause Axonal Loss via Different Mechanisms. Neuron 2020; 106:589-606.e6. [PMID: 32169171 PMCID: PMC7289150 DOI: 10.1016/j.neuron.2020.02.021] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/03/2020] [Accepted: 02/13/2020] [Indexed: 12/01/2022]
Abstract
ACOX1 (acyl-CoA oxidase 1) encodes the first and rate-limiting enzyme of the very-long-chain fatty acid (VLCFA) β-oxidation pathway in peroxisomes and leads to H2O2 production. Unexpectedly, Drosophila (d) ACOX1 is mostly expressed and required in glia, and loss of ACOX1 leads to developmental delay, pupal death, reduced lifespan, impaired synaptic transmission, and glial and axonal loss. Patients who carry a previously unidentified, de novo, dominant variant in ACOX1 (p.N237S) also exhibit glial loss. However, this mutation causes increased levels of ACOX1 protein and function resulting in elevated levels of reactive oxygen species in glia in flies and murine Schwann cells. ACOX1 (p.N237S) patients exhibit a severe loss of Schwann cells and neurons. However, treatment of flies and primary Schwann cells with an antioxidant suppressed the p.N237S-induced neurodegeneration. In summary, both loss and gain of ACOX1 lead to glial and neuronal loss, but different mechanisms are at play and require different treatments.
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Affiliation(s)
- Hyung-Lok Chung
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Paul C Marcogliese
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Juyeon Jo
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Department of Pediatrics, Section of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Thomas A Ravenscroft
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Lita Duraine
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sina Sadeghzadeh
- Department of Psychology, Harvard University, Cambridge, MA 02138, USA
| | - David Li-Kroeger
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Robert E Schmidt
- Department of Pathology and Immunology, Division of Neuropathology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alan Pestronk
- Department of Pathology and Immunology, Division of Neuropathology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lindsay Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mitchell J Herndon
- Department of Pathology and Immunology, Division of Neuropathology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shan Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Amelle Shillington
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Marissa Vawter-Lee
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Robert Hopkin
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Jackeline Rodriguez-Smith
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; Division of Rheumatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Michael Henrickson
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; Division of Rheumatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ann B Moser
- Division of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Richard O Jones
- Division of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Paul Watkins
- Division of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Taekyeong Yoo
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Soe Mar
- Department of Neurology, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Murim Choi
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Robert C Bucelli
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hyun Kyoung Lee
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Section of Neurology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Carlos E Prada
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Jong-Hee Chae
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Tiphanie P Vogel
- Department of Pediatrics, Section of Rheumatology, Baylor College of Medicine, Center for Human Immunobiology, Texas Children's Hospital, Houston, TX 77030, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
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Ansar M, Paracha SA, Serretti A, Sarwar MT, Khan J, Ranza E, Falconnet E, Iwaszkiewicz J, Shah SF, Qaisar AA, Santoni FA, Zoete V, Megarbane A, Ahmed J, Colombo R, Makrythanasis P, Antonarakis SE. Biallelic variants in FBXL3 cause intellectual disability, delayed motor development and short stature. Hum Mol Genet 2020; 28:972-979. [PMID: 30481285 DOI: 10.1093/hmg/ddy406] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/13/2018] [Accepted: 11/14/2018] [Indexed: 12/20/2022] Open
Abstract
FBXL3 (F-Box and Leucine Rich Repeat Protein 3) encodes a protein that contains an F-box and several tandem leucine-rich repeats (LRR) domains. FBXL3 is part of the SCF (Skp1-Cullin-F box protein) ubiquitin ligase complex that binds and leads to phosphorylation-dependent degradation of the central clock protein cryptochromes (CRY1 and CRY2) by the proteasome and its absence causes circadian phenotypes in mice and behavioral problems. No FBXL3-related phenotypes have been described in humans. By a combination of exome sequencing and homozygosity mapping, we analyzed two consanguineous families with intellectual disability and identified homozygous loss-of-function (LoF) variants in FBXL3. In the first family, from Pakistan, an FBXL3 frameshift variant [NM_012158.2:c.885delT:p.(Leu295Phefs*25)] was the onlysegregating variant in five affected individuals in two family loops (LOD score: 3.12). In the second family, from Lebanon, we identified a nonsense variant [NM_012158.2:c.445C>T:p.(Arg149*)]. In a third patient from Italy, a likely deleterious non-synonymous variant [NM_012158.2:c.1072T>C:p.(Cys358Arg)] was identified in homozygosity. Protein 3D modeling predicted that the Cys358Arg change influences the binding with CRY2 by destabilizing the structure of the FBXL3, suggesting that this variant is also likely to be LoF. The eight affected individuals from the three families presented with a similar phenotype that included intellectual disability, developmental delay, short stature and mild facial dysmorphism, mainly large nose with a bulbous tip. The phenotypic similarity and the segregation analysis suggest that FBXL3 biallelic, LoF variants link this gene with syndromic autosomal recessive developmental delay/intellectual disability.
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Affiliation(s)
- Muhammad Ansar
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland
| | - Sohail Aziz Paracha
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan
| | - Alessandro Serretti
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Muhammad T Sarwar
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan
| | - Jamshed Khan
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan
| | - Emmanuelle Ranza
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Service of Genetic Medicine, University Hospitals of Geneva, Geneva, Switzerland
| | - Emilie Falconnet
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland
| | - Justyna Iwaszkiewicz
- Swiss Institute of Bioinformatics, Molecular Modeling Group, Batiment Genopode, Unil Sorge, Lausanne, Switzerland
| | - Sayyed Fahim Shah
- Department of Medicine, KMU Institute of Medical Sciences, Kohat, Pakistan
| | | | - Federico A Santoni
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Department of Endocrinology Diabetes and Metabolism, University Hospital of Lausanne, Lausanne, Switzerland
| | - Vincent Zoete
- Swiss Institute of Bioinformatics, Molecular Modeling Group, Batiment Genopode, Unil Sorge, Lausanne, Switzerland.,Department of Fundamental Oncology, Lausanne University, Ludwig Institute for Cancer Research, Route de la Corniche 9A, Epalinges, Switzerland
| | | | - Jawad Ahmed
- Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan
| | - Roberto Colombo
- Institute of Clinical Biochemistry, Faculty of Medicine, Catholic University IRCCS Policlinico Gemelli, Rome, Italy.,Center for the Study of Rare Hereditary Diseases, Niguarda Ca' Granda Metropolitan Hospital, Milan, Italy
| | - Periklis Makrythanasis
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Stylianos E Antonarakis
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Service of Genetic Medicine, University Hospitals of Geneva, Geneva, Switzerland.,iGE3 Institute of Genetics and Genomics of Geneva, Geneva, Switzerland
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Bellen HJ, Wangler MF, Yamamoto S. The fruit fly at the interface of diagnosis and pathogenic mechanisms of rare and common human diseases. Hum Mol Genet 2019; 28:R207-R214. [PMID: 31227826 PMCID: PMC6872428 DOI: 10.1093/hmg/ddz135] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 05/31/2019] [Accepted: 06/07/2019] [Indexed: 12/12/2022] Open
Abstract
Drosophila melanogaster is a unique, powerful genetic model organism for studying a broad range of biological questions. Human studies that probe the genetic causes of rare and undiagnosed diseases using massive-parallel sequencing often require complementary gene function studies to determine if and how rare variants affect gene function. These studies also provide inroads to disease mechanisms and therapeutic targets. In this review we discuss strategies for functional studies of rare human variants in Drosophila. We focus on our experience in establishing a Drosophila core of the Model Organisms Screening Center for the Undiagnosed Diseases Network (UDN) and concurrent fly studies with other large genomic rare disease research efforts such as the Centers for Mendelian Genomics. We outline four major strategies that use the latest technology in fly genetics to understand the impact of human variants on gene function. We also mention general concepts in probing disease mechanisms, therapeutics and using rare disease to understand common diseases. Drosophila is and will continue to be a fundamental genetic model to identify new disease-causing variants, pathogenic mechanisms and drugs that will impact medicine.
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Affiliation(s)
- Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine (BCM), Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX , USA
- Howard Hughes Medical Institute, Houston, TX, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX , USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine (BCM), Houston, TX, USA
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX , USA
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Ansar M, Chung HL, Al-Otaibi A, Elagabani MN, Ravenscroft TA, Paracha SA, Scholz R, Abdel Magid T, Sarwar MT, Shah SF, Qaisar AA, Makrythanasis P, Marcogliese PC, Kamsteeg EJ, Falconnet E, Ranza E, Santoni FA, Aldhalaan H, Al-Asmari A, Faqeih EA, Ahmed J, Kornau HC, Bellen HJ, Antonarakis SE. Bi-allelic Variants in IQSEC1 Cause Intellectual Disability, Developmental Delay, and Short Stature. Am J Hum Genet 2019; 105:907-920. [PMID: 31607425 DOI: 10.1016/j.ajhg.2019.09.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/11/2019] [Indexed: 12/30/2022] Open
Abstract
We report two consanguineous families with probands that exhibit intellectual disability, developmental delay, short stature, aphasia, and hypotonia in which homozygous non-synonymous variants were identified in IQSEC1 (GenBank: NM_001134382.3). In a Pakistani family, the IQSEC1 segregating variant is c.1028C>T (p.Thr343Met), while in a Saudi Arabian family the variant is c.962G>A (p.Arg321Gln). IQSEC1-3 encode guanine nucleotide exchange factors for the small GTPase ARF6 and their loss affects a variety of actin-dependent cellular processes, including AMPA receptor trafficking at synapses. The ortholog of IQSECs in the fly is schizo and its loss affects growth cone guidance at the midline in the CNS, also an actin-dependent process. Overexpression of the reference IQSEC1 cDNA in wild-type flies is lethal, but overexpression of the two variant IQSEC1 cDNAs did not affect viability. Loss of schizo caused embryonic lethality that could be rescued to 2nd instar larvae by moderate expression of the human reference cDNA. However, the p.Arg321Gln and p.Thr343Met variants failed to rescue embryonic lethality. These data indicate that the variants behave as loss-of-function mutations. We also show that schizo in photoreceptors is required for phototransduction. Finally, mice with a conditional Iqsec1 deletion in cortical neurons exhibited an increased density of dendritic spines with an immature morphology. The phenotypic similarity of the affecteds and the functional experiments in flies and mice indicate that IQSEC1 variants are the cause of a recessive disease with intellectual disability, developmental delay, and short stature, and that axonal guidance and dendritic projection defects as well as dendritic spine dysgenesis may underlie disease pathogenesis.
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Harnish JM, Deal SL, Chao HT, Wangler MF, Yamamoto S. In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila. J Vis Exp 2019:10.3791/59658. [PMID: 31498321 PMCID: PMC7418855 DOI: 10.3791/59658] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Advances in sequencing technology have made whole-genome and whole-exome datasets more accessible for both clinical diagnosis and cutting-edge human genetics research. Although a number of in silico algorithms have been developed to predict the pathogenicity of variants identified in these datasets, functional studies are critical to determining how specific genomic variants affect protein function, especially for missense variants. In the Undiagnosed Diseases Network (UDN) and other rare disease research consortia, model organisms (MO) including Drosophila, C. elegans, zebrafish, and mice are actively used to assess the function of putative human disease-causing variants. This protocol describes a method for the functional assessment of rare human variants used in the Model Organisms Screening Center Drosophila Core of the UDN. The workflow begins with gathering human and MO information from multiple public databases, using the MARRVEL web resource to assess whether the variant is likely to contribute to a patient's condition as well as design effective experiments based on available knowledge and resources. Next, genetic tools (e.g., T2A-GAL4 and UAS-human cDNA lines) are generated to assess the functions of variants of interest in Drosophila. Upon development of these reagents, two-pronged functional assays based on rescue and overexpression experiments can be performed to assess variant function. In the rescue branch, the endogenous fly genes are "humanized" by replacing the orthologous Drosophila gene with reference or variant human transgenes. In the overexpression branch, the reference and variant human proteins are exogenously driven in a variety of tissues. In both cases, any scorable phenotype (e.g., lethality, eye morphology, electrophysiology) can be used as a read-out, irrespective of the disease of interest. Differences observed between reference and variant alleles suggest a variant-specific effect, and thus likely pathogenicity. This protocol allows rapid, in vivo assessments of putative human disease-causing variants of genes with known and unknown functions.
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Affiliation(s)
- J Michael Harnish
- Department of Molecular and Human Genetics, Baylor College of Medicine
| | - Samantha L Deal
- Program in Developmental Biology, Baylor College of Medicine
| | - Hsiao-Tuan Chao
- Department of Molecular and Human Genetics, Baylor College of Medicine; Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital; Department of Neuroscience, Baylor College of Medicine
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine; Program in Developmental Biology, Baylor College of Medicine; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine; Program in Developmental Biology, Baylor College of Medicine; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital; Department of Neuroscience, Baylor College of Medicine;
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Ansar M, Ullah F, Paracha SA, Adams DJ, Lai A, Pais L, Iwaszkiewicz J, Millan F, Sarwar MT, Agha Z, Shah SF, Qaisar AA, Falconnet E, Zoete V, Ranza E, Makrythanasis P, Santoni FA, Ahmed J, Katsanis N, Walsh C, Davis EE, Antonarakis SE. Bi-allelic Variants in DYNC1I2 Cause Syndromic Microcephaly with Intellectual Disability, Cerebral Malformations, and Dysmorphic Facial Features. Am J Hum Genet 2019; 104:1073-1087. [PMID: 31079899 PMCID: PMC6556908 DOI: 10.1016/j.ajhg.2019.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/01/2019] [Indexed: 12/30/2022] Open
Abstract
Cargo transport along the cytoplasmic microtubular network is essential for neuronal function, and cytoplasmic dynein-1 is an established molecular motor that is critical for neurogenesis and homeostasis. We performed whole-exome sequencing, homozygosity mapping, and chromosomal microarray studies in five individuals from three independent pedigrees and identified likely-pathogenic variants in DYNC1I2 (Dynein Cytoplasmic 1 Intermediate Chain 2), encoding a component of the cytoplasmic dynein 1 complex. In a consanguineous Pakistani family with three affected individuals presenting with microcephaly, severe intellectual disability, simplification of cerebral gyration, corpus callosum hypoplasia, and dysmorphic facial features, we identified a homozygous splice donor site variant (GenBank: NM_001378.2:c.607+1G>A). We report two additional individuals who have similar neurodevelopmental deficits and craniofacial features and harbor deleterious variants; one individual bears a c.740A>G (p.Tyr247Cys) change in trans with a 374 kb deletion encompassing DYNC1I2, and an unrelated individual harbors the compound-heterozygous variants c.868C>T (p.Gln290∗) and c.740A>G (p.Tyr247Cys). Zebrafish larvae subjected to CRISPR-Cas9 gene disruption or transient suppression of dync1i2a displayed significantly altered craniofacial patterning with concomitant reduction in head size. We monitored cell death and cell cycle progression in dync1i2a zebrafish models and observed significantly increased apoptosis, likely due to prolonged mitosis caused by abnormal spindle morphology, and this finding offers initial insights into the cellular basis of microcephaly. Additionally, complementation studies in zebrafish demonstrate that p.Tyr247Cys attenuates gene function, consistent with protein structural analysis. Our genetic and functional data indicate that DYNC1I2 dysfunction probably causes an autosomal-recessive microcephaly syndrome and highlight further the critical roles of the dynein-1 complex in neurodevelopment.
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Affiliation(s)
- Muhammad Ansar
- Department of Genetic Medicine and Development, University of Geneva, 1206 Geneva, Switzerland
| | - Farid Ullah
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27701, USA; Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, 38000 Faisalabad, Pakistan; Pakistan Institute of Engineering and Applied Sciences, 45650 Islamabad, Pakistan
| | - Sohail A Paracha
- Institute of Basic Medical Sciences, Khyber Medical University, 25100 Peshawar, Pakistan
| | - Darius J Adams
- Atlantic Health System, Goryeb Children's Hospital, Morristown, NJ 07960, USA
| | - Abbe Lai
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Departments of Neurology and Pediatrics, Harvard Medical School, Center for Life Sciences, Blackfan Circle, Boston, MA 02115, USA
| | - Lynn Pais
- Medical and Population Genetics Program, Broad Institute of MIT, Cambridge, MA 02142, USA; Center for Mendelian Genomics, Harvard University, Cambridge, MA 02142, USA
| | - Justyna Iwaszkiewicz
- Swiss Institute of Bioinformatics, Molecular Modeling Group, Batiment Genopode, Unil Sorge, 1015 Lausanne, Switzerland
| | | | - Muhammad T Sarwar
- Institute of Basic Medical Sciences, Khyber Medical University, 25100 Peshawar, Pakistan
| | - Zehra Agha
- Department of Biosciences, COMSATS University, 45500 Islamabad, Pakistan
| | - Sayyed Fahim Shah
- Department of Medicine, KMU Institute of Medical Sciences, 26000 Kohat, Pakistan
| | - Azhar Ali Qaisar
- Radiology Department, Lady Reading Hospital, 25000 Peshawar, Pakistan
| | - Emilie Falconnet
- Department of Genetic Medicine and Development, University of Geneva, 1206 Geneva, Switzerland
| | - Vincent Zoete
- Swiss Institute of Bioinformatics, Molecular Modeling Group, Batiment Genopode, Unil Sorge, 1015 Lausanne, Switzerland; Department of Fundamental Oncology, Lausanne University, Ludwig Institute for Cancer Research, Route de la Corniche 9A, 1066 Epalinges, Switzerland
| | - Emmanuelle Ranza
- Department of Genetic Medicine and Development, University of Geneva, 1206 Geneva, Switzerland; Service of Genetic Medicine, University Hospitals of Geneva, 1205 Geneva, Switzerland
| | - Periklis Makrythanasis
- Department of Genetic Medicine and Development, University of Geneva, 1206 Geneva, Switzerland; Biomedical Research Foundation of the Academy of Athens, 115 27 Athens, Greece
| | - Federico A Santoni
- Department of Genetic Medicine and Development, University of Geneva, 1206 Geneva, Switzerland; Department of Endocrinology Diabetes and Metabolism, University Hospital of Lausanne, 1011 Lausanne, Switzerland
| | - Jawad Ahmed
- Institute of Basic Medical Sciences, Khyber Medical University, 25100 Peshawar, Pakistan
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27701, USA
| | - Christopher Walsh
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Departments of Neurology and Pediatrics, Harvard Medical School, Center for Life Sciences, Blackfan Circle, Boston, MA 02115, USA; Medical and Population Genetics Program, Broad Institute of MIT, Cambridge, MA 02142, USA; Center for Mendelian Genomics, Harvard University, Cambridge, MA 02142, USA
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27701, USA.
| | - Stylianos E Antonarakis
- Department of Genetic Medicine and Development, University of Geneva, 1206 Geneva, Switzerland; Service of Genetic Medicine, University Hospitals of Geneva, 1205 Geneva, Switzerland; iGE3 Institute of Genetics and Genomics of Geneva, 1211 Geneva, Switzerland.
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Bi-allelic Loss-of-Function Variants in DNMBP Cause Infantile Cataracts. Am J Hum Genet 2018; 103:568-578. [PMID: 30290152 DOI: 10.1016/j.ajhg.2018.09.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 09/04/2018] [Indexed: 12/11/2022] Open
Abstract
Infantile and childhood-onset cataracts form a heterogeneous group of disorders; among the many genetic causes, numerous pathogenic variants in additional genes associated with autosomal-recessive infantile cataracts remain to be discovered. We identified three consanguineous families affected by bilateral infantile cataracts. Using exome sequencing, we found homozygous loss-of-function variants in DNMBP: nonsense variant c.811C>T (p.Arg271∗) in large family F385 (nine affected individuals; LOD score = 5.18 at θ = 0), frameshift deletion c.2947_2948del (p.Asp983∗) in family F372 (two affected individuals), and frameshift variant c.2852_2855del (p.Thr951Metfs∗41) in family F3 (one affected individual). The phenotypes of all affected individuals include infantile-onset cataracts. RNAi-mediated knockdown of the Drosophila ortholog still life (sif), enriched in lens-secreting cells, affects the development of these cells as well as the localization of E-cadherin, alters the distribution of septate junctions in adjacent cone cells, and leads to a ∼50% reduction in electroretinography amplitudes in young flies. DNMBP regulates the shape of tight junctions, which correspond to the septate junctions in invertebrates, as well as the assembly pattern of E-cadherin in human epithelial cells. E-cadherin has an important role in lens vesicle separation and lens epithelial cell survival in humans. We therefore conclude that DNMBP loss-of-function variants cause infantile-onset cataracts in humans.
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