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Liu W, Xiu L, Zhou M, Li T, Jiang N, Wan Y, Qiu C, Li J, Hu W, Zhang W, Wu J. The Critical Role of the Shroom Family Proteins in Morphogenesis, Organogenesis and Disease. PHENOMICS (CHAM, SWITZERLAND) 2024; 4:187-202. [PMID: 38884059 PMCID: PMC11169129 DOI: 10.1007/s43657-023-00119-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 07/07/2023] [Accepted: 07/13/2023] [Indexed: 06/18/2024]
Abstract
The Shroom (Shrm) family of actin-binding proteins has a unique and highly conserved Apx/Shrm Domain 2 (ASD2) motif. Shroom protein directs the subcellular localization of Rho-associated kinase (ROCK), which remodels the actomyosin cytoskeleton and changes cellular morphology via its ability to phosphorylate and activate non-muscle myosin II. Therefore, the Shrm-ROCK complex is critical for the cellular shape and the development of many tissues, including the neural tube, eye, intestines, heart, and vasculature system. Importantly, the structure and expression of Shrm proteins are also associated with neural tube defects, chronic kidney disease, metastasis of carcinoma, and X-link mental retardation. Therefore, a better understanding of Shrm-mediated signaling transduction pathways is essential for the development of new therapeutic strategies to minimize damage resulting in abnormal Shrm proteins. This paper provides a comprehensive overview of the various Shrm proteins and their roles in morphogenesis and disease.
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Affiliation(s)
- Wanling Liu
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Lei Xiu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Mingzhe Zhou
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Tao Li
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
| | - Ning Jiang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Yanmin Wan
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Chao Qiu
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032 China
| | - Jian Li
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Wei Hu
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Monglia University, Hohhot, 010030 China
| | - Wenhong Zhang
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
- Shanghai Huashen Institute of Microbes and Infections, Shanghai, 200052 China
| | - Jing Wu
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200438 China
- Shanghai Huashen Institute of Microbes and Infections, Shanghai, 200052 China
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Sahajpal N, Ziats C, Chaubey A, DuPont BR, Abidi F, Schwartz CE, Stevenson RE. Clinical findings in individuals with duplication of genes associated with X-linked intellectual disability. Clin Genet 2024; 105:173-184. [PMID: 37899624 DOI: 10.1111/cge.14445] [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: 08/09/2023] [Revised: 09/25/2023] [Accepted: 10/13/2023] [Indexed: 10/31/2023]
Abstract
Duplication of all genes associated with X-linked intellectual disability (XLID) have been reported but the majority of the duplications include more than one XLID gene. It is exceptional for whole XLID gene duplications to cause the same phenotype as sequence variants or deletions of the same gene. Duplication of PLP1, the gene associated with Pelizaeus-Merzbacher syndrome, is the most notable duplication of this type. More commonly, duplication of XLID genes results in very different phenotypes than sequence alterations or deletions. Duplication of MECP2 is widely recognized as a duplication of this type, but a number of others exist. The phenotypes associated with gene duplications are often milder than those caused by deletions and sequence variants. Among some duplications that are clinically significant, marked skewing of X-inactivation in female carriers has been observed. This report describes the phenotypic consequences of duplication of 22 individual XLID genes, of which 10 are described for the first time.
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Affiliation(s)
- Nikhil Sahajpal
- Diagnostic Laboratories, Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Catherine Ziats
- Genetics Department, Shodair Children's Hospital, Helena, Montana, USA
| | - Alka Chaubey
- Clinical and Scientific Affairs, Bionano Genomics, San Diego, California, USA
| | - Barbara R DuPont
- Diagnostic Laboratories, Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Fatima Abidi
- Diagnostic Laboratories, Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Charles E Schwartz
- Department of Pediatrics and Human Development, Michigan State University, Grand Rapids, Michigan, USA
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Kolvenbach CM, Felger T, Schierbaum L, Thiffault I, Pastinen T, Szczepańska M, Zaniew M, Adamczyk P, Bayat A, Yilmaz Ö, Lindenberg TT, Thiele H, Hildebrandt F, Hinderhofer K, Moog U, Hilger AC, Sullivan B, Bartik L, Gnyś P, Grote P, Odermatt B, Reutter HM, Dworschak GC. X-linked variations in SHROOM4are implicated in congenital anomalies of the urinary tract and the anorectal, cardiovascular and central nervous systems. J Med Genet 2022; 60:587-596. [PMID: 36379543 DOI: 10.1136/jmg-2022-108738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 10/01/2022] [Indexed: 11/16/2022]
Abstract
BackgroundSHROOM4is thought to play an important role in cytoskeletal modification and development of the early nervous system. Previously, single-nucleotide variants (SNVs) or copy number variations (CNVs) inSHROOM4have been associated with the neurodevelopmental disorder Stocco dos Santos syndrome, but not with congenital anomalies of the urinary tract and the visceral or the cardiovascular system.MethodsHere, exome sequencing and CNV analyses besides expression studies in zebrafish and mouse andknockdown(KD) experiments using a splice blocking morpholino in zebrafish were performed to study the role ofSHROOM4during embryonic development.ResultsIn this study, we identified putative disease-causing SNVs and CNVs inSHROOM4in six individuals from four families with congenital anomalies of the urinary tract and the anorectal, cardiovascular and central nervous systems (CNS). Embryonic mouse and zebrafish expression studies showedShroom4expression in the upper and lower urinary tract, the developing cloaca, the heart and the cerebral CNS. KD studies in zebrafish larvae revealed pronephric cysts, anomalies of the cloaca and the heart, decreased eye-to-head ratio and higher mortality compared with controls. These phenotypes could be rescued by co-injection of human wild-typeSHROOM4mRNA and morpholino.ConclusionThe identified SNVs and CNVs in affected individuals with congenital anomalies of the urinary tract, the anorectal, the cardiovascular and the central nervous systems, and subsequent embryonic mouse and zebrafish studies suggestSHROOM4as a developmental gene for different organ systems.
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Peduto C, Piluso G, Nigro V, Brunetti-Pierri N. Are SHROOM4 loss-of-function variants pathogenic? Am J Med Genet A 2022; 188:3374-3375. [PMID: 36209347 DOI: 10.1002/ajmg.a.62935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/03/2022] [Accepted: 06/02/2022] [Indexed: 01/31/2023]
Affiliation(s)
- Cristina Peduto
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Giulio Piluso
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Vincenzo Nigro
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy.,Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Translational Medicine, University of Naples "Federico II", Naples, Italy
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Costa BC, Grangeia A, Galvão J, Vaz D, Melo M, Carraca T, Ramalho C, Dória S. Prenatal diagnosis study using array comparative genomic hybridization for genotype-phenotype correlation in 772 fetuses. Ann Diagn Pathol 2022; 61:152059. [DOI: 10.1016/j.anndiagpath.2022.152059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 11/25/2022]
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Liao WP, Chen Q, Jiang YW, Luo S, Liu XR. Editorial: Sub-molecular mechanism of genetic epilepsy. Front Mol Neurosci 2022; 15:958747. [PMID: 35959103 PMCID: PMC9360914 DOI: 10.3389/fnmol.2022.958747] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Wei-Ping Liao
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
- *Correspondence: Wei-Ping Liao
| | - Qian Chen
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Yu-Wu Jiang
- Department of Pediatrics, Peking University First Hospital, Peking, China
| | - Sheng Luo
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
| | - Xiao-Rong Liu
- Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province, Ministry of Education of China, Guangzhou, China
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Bian WJ, Li ZJ, Wang J, Luo S, Li BM, Gao LD, He N, Yi YH. SHROOM4 Variants Are Associated With X-Linked Epilepsy With Features of Generalized Seizures or Generalized Discharges. Front Mol Neurosci 2022; 15:862480. [PMID: 35663265 PMCID: PMC9157246 DOI: 10.3389/fnmol.2022.862480] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectiveSHROOM4 gene encodes an actin-binding proteins, which plays an important role in cytoskeletal architecture, synaptogenesis, and maintaining gamma-aminobutyric acid receptors-mediated inhibition. SHROOM4 mutations were reported in patients with the Stocco dos Santos type of X-linked syndromic intellectual developmental disorder (SDSX; OMIM# 300434). In this study, we investigated the association between SHROOM4 and epilepsy.MethodsTrios-based whole-exome sequencing was performed in a cohort of 320 cases with idiopathic generalized epilepsy or idiopathic partial epilepsy. Protein modeling was used to assess the damaging effects of variations.ResultsSix hemizygous missense SHROOM4 variants, including c.13C > A/p. Pro5Thr, c.3236C > T/p.Glu1079Ala, c.3581C > T/p.Ser1194Leu, c.4288C > T/p.Arg1430Cys, c.4303G > A/p.Val1435Met, c.4331C > T/p.Pro1444Leu, were identified in six cases with idiopathic epilepsy without intellectual disability. All patients presented with features of generalized seizures or generalized discharges. These hemizygous variants had no or extremely low allele frequencies in controls and showed statistically higher frequency in the case cohort than controls. All variants were predicted to alter hydrogen bond with surrounding amino acids or decreased protein stability. The SHROOM4 variants reported in patients with SDSX were mostly destructive or duplicative variants; in contrast, the SHROOM4 variants were all missense variants, suggesting a potential genotype-phenotype correlation. The two missense variants associated with SDSX were located in the middle of SHROOM4 protein, whereas variants associated with idiopathic epilepsy were located around the N-terminal PDZ domain and the C-terminal ASD2 domain.SignificanceSHROOM4 was potentially a candidate pathogenic gene of idiopathic epilepsy without intellectual disability. The genotype-phenotype correlation and sub-regional effect helps understanding the mechanism underlying phenotypic variation.
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Cao J, Xian W, Palihati M, Zhu Y, Wang G, Xie Y, Zhou G, You L. Deficiency of intellectual disability-related gene Brpf1 reduced inhibitory neurotransmission in MGE-derived GABAergic interneurons. G3-GENES GENOMES GENETICS 2021; 11:6179329. [PMID: 33744924 PMCID: PMC8496217 DOI: 10.1093/g3journal/jkab090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/09/2021] [Indexed: 12/13/2022]
Abstract
Intellectual disability is closely related to impaired GABA neurotransmission. Brpf1 was specifically expressed in medial ganglionic eminence (MGE), a developmental niche of GABAergic interneurons, and patients with BRPF1 mutations showed intellectual disability. To test its role in the development and function of MGE-derived GABAergic interneurons, we performed immunofluorescence staining, whole-cell patch-clamp, MGE transplantation, and mRNA-Seq to understand its effect on neuronal differentiation, dendritic morphology, electrophysiology, migration, and gene regulation, using mouse MGE-derived GABAergic interneurons infected with AAV-shBrpf1. The results showed that Brpf1 knockdown had a decreasing trend, although not significant, on the differentiation of GABAergic interneurons into parvalbumin+ interneurons. Moreover, increased firing threshold, decreased number of evoked action potentials, and a reduced amplitude of miniature inhibitory postsynaptic currents were observed before any significant change of MAP2+ dendritic morphology and in vivo migration ability appeared. Finally, mRNA-Seq analysis revealed that genes related to neurodevelopment and synaptic transmission such as Map2k7 were dysregulated. Our results demonstrated a key role of Brpf1 in inhibitory neurotransmission and related gene expression of GABAergic interneurons.
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Affiliation(s)
- Jingli Cao
- Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Weiwei Xian
- Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Maierdan Palihati
- Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yu Zhu
- Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Guoxiang Wang
- Institutes of Brain Sciences, Fudan University, Shanghai 200032, China
| | - Yunli Xie
- Institutes of Brain Sciences, Fudan University, Shanghai 200032, China
| | - Guomin Zhou
- Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.,Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai 200032, China
| | - Linya You
- Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.,Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai 200032, China
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Atypical presentation of Dent disease in a patient with interstitial Xp11.22 deletion. J Nephrol 2021; 34:2111-2115. [PMID: 33420968 DOI: 10.1007/s40620-020-00959-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 12/27/2020] [Indexed: 10/22/2022]
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Deciphering the complexity of simple chromosomal insertions by genome sequencing. Hum Genet 2020; 140:361-380. [PMID: 32728808 DOI: 10.1007/s00439-020-02210-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022]
Abstract
Chromosomal insertions are thought to be rare structural rearrangements. The current understanding of the underlying mechanisms of their origin is still limited. In this study, we sequenced 16 cases with apparent simple insertions previously identified by karyotyping and/or chromosomal microarray analysis. Using mate-pair genome sequencing (GS), we identified all 16 insertions and revised previously designated karyotypes in 75.0% (12/16) of the cases. Additional cryptic rearrangements were identified in 68.8% of the cases (11/16). The incidence of additional cryptic rearrangements in chromosomal insertions was significantly higher compared to balanced translocations and inversions reported in other studies by GS. We characterized and classified the cryptic insertion rearrangements into four groups, which were not mutually exclusive: (1) insertion segments were fragmented and their subsegments rearranged and clustered at the insertion site (10/16, 62.5%); (2) one or more cryptic subsegments were not inserted into the insertion site (5/16, 31.3%); (3) segments of the acceptor chromosome were scattered and rejoined with the insertion segments (2/16, 12.5%); and (4) copy number gains were identified in the flanking regions of the insertion site (2/16, 12.5%). In addition to the observation of these chromothripsis- or chromoanasynthesis-like events, breakpoint sequence analysis revealed microhomology to be the predominant feature. However, no significant correlation was found between the number of cryptic rearrangements and the size of the insertion. Overall, our study provide molecular characterization of karyotypically apparent simple insertions, demonstrate previously underappreciated complexities, and evidence that chromosomal insertions are likely formed by nonhomologous end joining and/or microhomology-mediated replication-based DNA repair.
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Overexpression of Shrm4 promotes proliferation and differentiation of neural stem cells through activation of GABA signaling pathway. Mol Cell Biochem 2019; 463:115-126. [PMID: 31654185 DOI: 10.1007/s11010-019-03634-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 09/25/2019] [Indexed: 10/25/2022]
Abstract
Shrm4 is a protein that is exclusively expressed in polarized tissues. The physiological function of Shrm4 in the brain was required to be elucidated. Thus, we aimed to explore how the Shrm4-mediated gamma-aminobutyric acid (GABA) pathway affected neural stem cells (NSCs). At first, the Nestin expression in cultured NSCs was identified. After determination of the interaction of Shrm4 and GABAB1, a series of in vitro experiment were performed to detect cell proliferation, the ability of cell colony formation, degree that NSCs differentiated into neurons, the apoptosis rate, and cell cycle. The levels of Shrm4, GABAB1, Bcl-2-associated protein x (Bax), B cell lymphoma 2 (Bcl-2), cleaved Caspase-3, microtubule-associated protein 2 (MAP-2) as well as suppressor of cytokine signaling 2 (SOCS2) were detected to further assess the role of Shrm4 and GABA pathway in NSCs. Initially, we found that Shrm4 could bind to GABAB1, and overexpression of Shrm4 or activation of GABAB1 increased the number of positive cells, and promoted cell viability, colony formation rate and differentiation of NSCs. After overexpression of Shrm4 or activation of GABAB1, cells in the G1 phase were decreased, while those in the S phase were increased with an inhibited cell apoptosis rate in the NSCs. Besides, the overexpression of Shrm4 or activation of GABAB1 upregulated the levels of Shrm4, GABAB1, Bcl-2, MAP-2 and SOCS2, while downregulated Bax and cleaved Caspase-3 in NSCs. Overall, overexpression of Shrm4 activated GABAB1 to stimulate the proliferation and differentiation of NSCs. Thus, Shrm4 might be considered as a novel target for promoting the proliferation and differentiation of NSCs.
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Routier L, Verny F, Barcia G, Chemaly N, Desguerre I, Colleaux L, Nabbout R. Exome sequencing findings in 27 patients with myoclonic-atonic epilepsy: Is there a major genetic factor? Clin Genet 2019; 96:254-260. [PMID: 31170314 DOI: 10.1111/cge.13581] [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: 02/25/2019] [Revised: 05/22/2019] [Accepted: 06/02/2019] [Indexed: 01/31/2023]
Abstract
Myoclonic-atonic epilepsy (MAE) is thought to have a genetic etiology. Mutations in CHD2, SLC2A1 and SLC6A1 genes have been reported in few patients showing often intellectual disability prior to MAE onset. We aimed to explore putative causal genetic factors in MAE. We performed array-CGH and whole-exome sequencing in 27 patients. We considered non-synonymous variants, splice acceptor, donor site mutations, and coding insertions/deletions. A gene was causal when its mutations have been already linked to epilepsy or other brain diseases or when it has a putative function in neuronal excitability or brain development. We identified candidate disease-causing variants in 11 patients (41%). Single variants were found in some known epilepsy-associated genes (namely CHD2, KCNT1, KCNA2 and STXBP1) but not in others (SLC2A1 and SLC6A1). One new candidate gene SUN1 requires further validation. MAE shows underlying genetic heterogeneity with only few cases linked to mutations in genes reported in developmental and epileptic encephalopathies.
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Affiliation(s)
- Laura Routier
- Reference Centre for Rare Epilepsies, Pediatric Neurology, Necker Enfants-Malades Hospital, Paris, France.,Pediatric Neurology, Amiens-Picardie University Hospital, Amiens, France.,GRAMFC-INSERM U1105, UPJV, Amiens, France
| | - Florine Verny
- Reference Centre for Rare Epilepsies, Pediatric Neurology, Necker Enfants-Malades Hospital, Paris, France.,INSERM UMR1163, Translational Research for Neurological Disorders, Imagine Institute, Paris-Descartes University, Paris, France
| | - Giulia Barcia
- Clinical Genetics, Necker Enfants-Malades Hospital, Paris, France
| | - Nicole Chemaly
- Reference Centre for Rare Epilepsies, Pediatric Neurology, Necker Enfants-Malades Hospital, Paris, France.,INSERM UMR1163, Translational Research for Neurological Disorders, Imagine Institute, Paris-Descartes University, Paris, France
| | - Isabelle Desguerre
- Reference Centre for Rare Epilepsies, Pediatric Neurology, Necker Enfants-Malades Hospital, Paris, France
| | - Laurence Colleaux
- INSERM UMR1163, Translational Research for Neurological Disorders, Imagine Institute, Paris-Descartes University, Paris, France
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies, Pediatric Neurology, Necker Enfants-Malades Hospital, Paris, France.,INSERM UMR1163, Translational Research for Neurological Disorders, Imagine Institute, Paris-Descartes University, Paris, France
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Danyel M, Suk EK, Raile V, Gellermann J, Knaus A, Horn D. Familial Xp11.22 microdeletion including SHROOM4 and CLCN5 is associated with intellectual disability, short stature, microcephaly and Dent disease: a case report. BMC Med Genomics 2019; 12:6. [PMID: 30630535 PMCID: PMC6327553 DOI: 10.1186/s12920-018-0471-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/28/2018] [Indexed: 11/18/2022] Open
Abstract
Background Two interstitial microdeletions Xp11.22 including the CLCN5 and SHROOM4 genes were recently reported in a male individual affected with Dent disease, short stature, psychomotor delay and minor facial anomalies. Dent disease, characterized by a specific renal phenotype, is caused by truncating mutations of CLCN5 in the majority of affected cases. Case presentation Here, we present clinical and molecular findings in a male patient with clinical signs of Dent disease, developmental delay, short stature, microcephaly, and facial dysmorphism. Using molecular karyotyping we identified a hemizygous interstitial microdeletion Xp11.23p.11.22 of about 700 kb, which was inherited from his asymptomatic mother. Among the six deleted genes is CLCN5, which explains the renal phenotype in our patient. SHROOM4, which is partially deleted in this patient, is involved in neuronal development and was shown to be associated with X-linked intellectual disability. This is a candidate gene, the loss of which is thought to be associated with his further clinical manifestations. To rule out mutations in other genes related to intellectual disability, whole exome sequencing was performed. No other pathogenic variants that could explain the phenotypic features, were found. Conclusion We compared the clinical findings of the patient presented here with the reported case with an Xp11.22 microdeletion including CLCN5 and SHROOM4 and re-defined the phenotypic spectrum associated with this microdeletion. Electronic supplementary material The online version of this article (10.1186/s12920-018-0471-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Magdalena Danyel
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Eun Kyung Suk
- Praxis für Humangenetik-Friedrichstrasse, Berlin, Germany
| | - Vera Raile
- Department of Pediatric Neurology, Sozialpädiatrisches Zentrum (SPZ), Center for Chronically Sick Children, Charité - Universitätsmedizin Berlin, Germany, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Jutta Gellermann
- Department of Pediatric Nephrology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Berlin, Germany
| | - Denise Horn
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
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Associations between the clinical findings of cases having submicroscopic chromosomal imbalances at chromosomal breakpoints of apparently balanced structural rearrangements. GENE REPORTS 2017. [DOI: 10.1016/j.genrep.2017.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Grau C, Starkovich M, Azamian MS, Xia F, Cheung SW, Evans P, Henderson A, Lalani SR, Scott DA. Xp11.22 deletions encompassing CENPVL1, CENPVL2, MAGED1 and GSPT2 as a cause of syndromic X-linked intellectual disability. PLoS One 2017; 12:e0175962. [PMID: 28414775 PMCID: PMC5393878 DOI: 10.1371/journal.pone.0175962] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 04/03/2017] [Indexed: 12/27/2022] Open
Abstract
By searching a clinical database of over 60,000 individuals referred for array-based CNV analyses and online resources, we identified four males from three families with intellectual disability, developmental delay, hypotonia, joint hypermobility and relative macrocephaly who carried small, overlapping deletions of Xp11.22. The maximum region of overlap between their deletions spanned ~430 kb and included two pseudogenes, CENPVL1 and CENPVL2, whose functions are not known, and two protein coding genes-the G1 to S phase transition 2 gene (GSPT2) and the MAGE family member D1 gene (MAGED1). Deletions of this ~430 kb region have not been previously implicated in human disease. Duplications of GSPT2 have been documented in individuals with intellectual disability, but the phenotypic consequences of a loss of GSPT2 function have not been elucidated in humans or mouse models. Changes in MAGED1 have not been associated with intellectual disability in humans, but loss of MAGED1 function is associated with neurocognitive and neurobehavioral phenotypes in mice. In all cases, the Xp11.22 deletion was inherited from an unaffected mother. Studies performed on DNA from one of these mothers did not show evidence of skewed X-inactivation. These results suggest that deletions of an ~430 kb region on chromosome Xp11.22 that encompass CENPVL1, CENPVL2, GSPT2 and MAGED1 cause a distinct X-linked syndrome characterized by intellectual disability, developmental delay, hypotonia, joint hypermobility and relative macrocephaly. Loss of GSPT2 and/or MAGED1 function may contribute to the intellectual disability and developmental delay seen in males with these deletions.
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Affiliation(s)
- Christina Grau
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Molly Starkovich
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Mahshid S. Azamian
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Fan Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Baylor Genetics, Houston, Texas, Unite States of America
| | - Sau Wai Cheung
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Baylor Genetics, Houston, Texas, Unite States of America
| | - Patricia Evans
- Departments of Pediatrics and Neurology, University of Texas Southwestern Medical School, Dallas, Texas, United States of America
| | - Alex Henderson
- The Newcastle upon Tyne Hospitals, Newcastle upon Tyne, England
| | - Seema R. Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Daryl A. Scott
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
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16
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Epilepsy and intellectual disability linked protein Shrm4 interaction with GABA BRs shapes inhibitory neurotransmission. Nat Commun 2017; 8:14536. [PMID: 28262662 PMCID: PMC5343488 DOI: 10.1038/ncomms14536] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 01/09/2017] [Indexed: 02/07/2023] Open
Abstract
Shrm4, a protein expressed only in polarized tissues, is encoded by the KIAA1202 gene, whose mutations have been linked to epilepsy and intellectual disability. However, a physiological role for Shrm4 in the brain is yet to be established. Here, we report that Shrm4 is localized to synapses where it regulates dendritic spine morphology and interacts with the C terminus of GABAB receptors (GABABRs) to control their cell surface expression and intracellular trafficking via a dynein-dependent mechanism. Knockdown of Shrm4 in rat severely impairs GABABR activity causing increased anxiety-like behaviour and susceptibility to seizures. Moreover, Shrm4 influences hippocampal excitability by modulating tonic inhibition in dentate gyrus granule cells, in a process involving crosstalk between GABABRs and extrasynaptic δ-subunit-containing GABAARs. Our data highlights a role for Shrm4 in synaptogenesis and in maintaining GABABR-mediated inhibition, perturbation of which may be responsible for the involvement of Shrm4 in cognitive disorders and epilepsy. Mutations in the gene encoding Shrm4 are associated with epilepsy and intellectual disability. The authors show that Shrm4 interacts with GABAB receptors and regulates tonic inhibition in the hippocampus, and knockdown of Shrm4 in rats leads to anxiety-like behaviour and seizures.
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17
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Fieremans N, Van Esch H, Holvoet M, Van Goethem G, Devriendt K, Rosello M, Mayo S, Martinez F, Jhangiani S, Muzny DM, Gibbs RA, Lupski JR, Vermeesch JR, Marynen P, Froyen G. Identification of Intellectual Disability Genes in Female Patients with a Skewed X-Inactivation Pattern. Hum Mutat 2016; 37:804-11. [PMID: 27159028 DOI: 10.1002/humu.23012] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 04/22/2016] [Accepted: 04/26/2016] [Indexed: 12/30/2022]
Abstract
Intellectual disability (ID) is a heterogeneous disorder with an unknown molecular etiology in many cases. Previously, X-linked ID (XLID) studies focused on males because of the hemizygous state of their X chromosome. Carrier females are generally unaffected because of the presence of a second normal allele, or inactivation of the mutant X chromosome in most of their cells (skewing). However, in female ID patients, we hypothesized that the presence of skewing of X-inactivation would be an indicator for an X chromosomal ID cause. We analyzed the X-inactivation patterns of 288 females with ID, and found that 22 (7.6%) had extreme skewing (>90%), which is significantly higher than observed in the general population (3.6%; P = 0.029). Whole-exome sequencing of 19 females with extreme skewing revealed causal variants in six females in the XLID genes DDX3X, NHS, WDR45, MECP2, and SMC1A. Interestingly, variants in genes escaping X-inactivation presumably cause both XLID and skewing of X-inactivation in three of these patients. Moreover, variants likely accounting for skewing only were detected in MED12, HDAC8, and TAF9B. All tested candidate causative variants were de novo events. Hence, extreme skewing is a good indicator for the presence of X-linked variants in female patients.
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Affiliation(s)
- Nathalie Fieremans
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Belgium.,Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
| | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Maureen Holvoet
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Gert Van Goethem
- Het GielsBos, Gierle, Belgium and Department of Neurology, University Hospital of Antwerp (UZA), Antwerp, Belgium
| | - Koenraad Devriendt
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Monica Rosello
- Genetics Unit, Hospital Universitario y Politecnico La Fe, Valencia, Spain
| | - Sonia Mayo
- Genetics Unit, Hospital Universitario y Politecnico La Fe, Valencia, Spain
| | - Francisco Martinez
- Genetics Unit, Hospital Universitario y Politecnico La Fe, Valencia, Spain
| | - Shalini Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - James R Lupski
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Houston, Texas
| | - Joris R Vermeesch
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Peter Marynen
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Belgium
| | - Guy Froyen
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Belgium
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18
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Lopes F, Barbosa M, Ameur A, Soares G, de Sá J, Dias AI, Oliveira G, Cabral P, Temudo T, Calado E, Cruz IF, Vieira JP, Oliveira R, Esteves S, Sauer S, Jonasson I, Syvänen AC, Gyllensten U, Pinto D, Maciel P. Identification of novel genetic causes of Rett syndrome-likephenotypes. J Med Genet 2016; 53:190-9. [DOI: 10.1136/jmedgenet-2015-103568] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/06/2015] [Indexed: 11/04/2022]
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19
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Grams SE, Argiropoulos B, Lines M, Chakraborty P, Mcgowan-Jordan J, Geraghty MT, Tsang M, Eswara M, Tezcan K, Adams KL, Linck L, Himes P, Kostiner D, Zand DJ, Stalker H, Driscoll DJ, Huang T, Rosenfeld JA, Li X, Chen E. Genotype-phenotype characterization in 13 individuals with chromosome Xp11.22 duplications. Am J Med Genet A 2015; 170A:967-77. [PMID: 26692240 DOI: 10.1002/ajmg.a.37519] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/25/2015] [Indexed: 11/10/2022]
Abstract
We report 13 new individuals with duplications in Xp11.22-p11.23. The index family has one male and two female members in three generations with mild-severe intellectual disability (ID), speech delay, dysmorphic features, early puberty, constipation, and/or hand and foot abnormalities. Affected individuals were found to have two small duplications in Xp11.22 at nucleotide position (hg19) 50,112,063-50,456,458 bp (distal) and 53,160,114-53,713,154 bp (proximal). Collectively, these two regions include 14 RefSeq genes, prompting collection of a larger cohort of patients, in an attempt to delineate critical genes associated with the observed phenotype. In total, we have collected data on nine individuals with duplications overlapping the distal duplication region containing SHROOM4 and DGKK and eight individuals overlapping the proximal region including HUWE1. Duplications of HUWE1 have been previously associated with non-syndromic ID. Our data, with previously published reports, suggest that duplications involving SHROOM4 and DGKK may represent a new syndromic X-linked ID critical region associated with mild to severe ID, speech delay +/- dysarthria, attention deficit disorder, precocious puberty, constipation, and motor delay. We frequently observed foot abnormalities, 5th finger clinodactyly, tapering fingers, constipation, and exercise intolerance in patients with duplications of these two genes. Regarding duplications including the proximal region, our observations agree with previous studies, which have found associations with intellectual disability. In addition, expressive language delay, failure to thrive, motor delay, and 5th finger clinodactyly were also frequently observed in patients with the proximal duplication.
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Affiliation(s)
- Sarah E Grams
- Department of Medical Genetics, Kaiser Permanente, San Francisco, California
| | - Bob Argiropoulos
- Alberta Children's Hospital Research Institute for Child and Maternal Health, Alberta, Canada
| | - Matthew Lines
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.,Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Pranesh Chakraborty
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.,Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean Mcgowan-Jordan
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Michael T Geraghty
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.,Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Marilyn Tsang
- Department of Genetics, Sutter Memorial Hospital, Sacramento, California
| | - Marthand Eswara
- Department of Genetics, Sutter Memorial Hospital, Sacramento, California
| | - Kamer Tezcan
- Department of Genetics, Kaiser Permanente, Sacramento, California
| | - Kelly L Adams
- Department of Genetics, Kaiser Permanente, Sacramento, California
| | - Leesa Linck
- Department of Medical Genetics, Kaiser Permanente, Portland, Oregon
| | - Patricia Himes
- Department of Medical Genetics, Kaiser Permanente, Portland, Oregon
| | - Dana Kostiner
- Department of Medical Genetics, Kaiser Permanente, Portland, Oregon
| | - Dina J Zand
- Department of Medical Genetics, Children's National Medical Center, Washington DC
| | - Heather Stalker
- Department of Genetics, University of Florida, Gainesville, Florida
| | | | - Taosheng Huang
- Department of Human Genetics, Children's Hospital of Orange County, Orange, California
| | - Jill A Rosenfeld
- Signature Genomic Laboratories, Perkin Elmer, Inc., Spokane, Washington
| | - Xu Li
- Department of Genetics, Kaiser Permanente, San Jose, California
| | - Emily Chen
- Department of Medical Genetics, Kaiser Permanente, San Francisco, California.,Department of Genetics, Kaiser Permanente, San Jose, California
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20
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Dickson HM, Wilbur A, Reinke AA, Young MA, Vojtek AB. Targeted inhibition of the Shroom3-Rho kinase protein-protein interaction circumvents Nogo66 to promote axon outgrowth. BMC Neurosci 2015; 16:34. [PMID: 26077244 PMCID: PMC4467669 DOI: 10.1186/s12868-015-0171-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 06/03/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Inhibitory molecules in the adult central nervous system, including NogoA, impede neural repair by blocking axon outgrowth. The actin-myosin regulatory protein Shroom3 directly interacts with Rho kinase and conveys axon outgrowth inhibitory signals from Nogo66, a C-terminal inhibitory domain of NogoA. The purpose of this study was to identify small molecules that block the Shroom3-Rho kinase protein-protein interaction as a means to modulate NogoA signaling and, in the longer term, enhance axon outgrowth during neural repair. RESULTS A high throughput screen for inhibitors of the Shroom3-Rho kinase protein-protein interaction identified CCG-17444 (Chem ID: 2816053). CCG-17444 inhibits the Shroom3-Rho kinase interaction in vitro with micromolar potency. This compound acts through an irreversible, covalent mechanism of action, targeting Shroom3 Cys1816 to inhibit the Shroom3-Rho kinase protein-protein interaction. Inhibition of the Shroom3-Rho kinase protein-protein interaction with CCG-17444 counteracts the inhibitory action of Nogo66 and enhances neurite outgrowth. CONCLUSIONS This study identifies a small molecule inhibitor of the Shroom3-Rho kinase protein-protein interaction that circumvents the inhibitory action of Nogo66 in neurons. Identification of a small molecule compound that blocks the Shroom3-Rho kinase protein-protein interaction provides a first step towards a potential new strategy for enhancing neural repair.
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Affiliation(s)
- Heather M Dickson
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Amanda Wilbur
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Ashley A Reinke
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Mathew A Young
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Anne B Vojtek
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.
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21
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Armanet N, Metay C, Brisset S, Deschenes G, Pineau D, Petit FM, Di Rocco F, Goossens M, Tachdjian G, Labrune P, Tosca L. Double Xp11.22 deletion including SHROOM4 and CLCN5 associated with severe psychomotor retardation and Dent disease. Mol Cytogenet 2015; 8:8. [PMID: 25670966 PMCID: PMC4322561 DOI: 10.1186/s13039-015-0107-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/08/2015] [Indexed: 11/23/2022] Open
Abstract
Background Here we report the clinical and molecular characterization of two Xp11.22 deletions including SHROOM4 and CLCN5 genes. These deletions appeared in the same X chromosome of the same patient. Results The patient is a six-year-old boy who presented hydrocephalus, severe psychomotor and growth retardation, facial dysmorphism and renal proximal tubulopathy associated with low-molecular-weight proteinuria, hypercalciuria, hyperaminoaciduria, hypophosphatemia and hyperuricemia. Standard and high resolution karyotypes showed a 46,XY formula. Array-CGH revealed two consecutive cryptic deletions in the region Xp11.22, measuring respectively 148 Kb and 2.6 Mb. The two deletions were inherited from the asymptomatic mother. Conclusions Array-CGH allowed us to determine candidate genes in the deleted region. The disruption and partial loss of CLCN5 confirmed the diagnostic of Dent disease for this patient. Moreover, the previously described involvement of SHROOM4 in neuronal development is discussed.
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Affiliation(s)
- Narjes Armanet
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Corinne Metay
- Plateforme de Génomique IMRB 955, Hôpital Henri Mondor, Créteil, F-94010 France
| | - Sophie Brisset
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Georges Deschenes
- Service de Néphrologie pédiatrique, Hôpital Robert Debré, Paris, F-75935 France
| | - Dominique Pineau
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France
| | - François M Petit
- Laboratoire de Génétique Moléculaire, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, Clamart, F-92140 France
| | - Federico Di Rocco
- Service de Neurochirurgie pédiatrique, Hôpital Necker Enfants Malades, Clamart, F-75015 France
| | - Michel Goossens
- Plateforme de Génomique IMRB 955, Hôpital Henri Mondor, Créteil, F-94010 France.,Université Paris Est, Créteil, F-94010 France
| | - Gérard Tachdjian
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Philippe Labrune
- Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France.,Service de Pédiatrie, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, Clamart, F-92140 France
| | - Lucie Tosca
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
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22
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Nizon M, Andrieux J, Rooryck C, de Blois MC, Bourel-Ponchel E, Bourgois B, Boute O, David A, Delobel B, Duban-Bedu B, Giuliano F, Goldenberg A, Grotto S, Héron D, Karmous-Benailly H, Keren B, Lacombe D, Lapierre JM, Le Caignec C, Le Galloudec E, Le Merrer M, Le Moing AG, Mathieu-Dramard M, Nusbaum S, Pichon O, Pinson L, Raoul O, Rio M, Romana S, Roubertie A, Colleaux L, Turleau C, Vekemans M, Nabbout R, Malan V. Phenotype-genotype correlations in 17 new patients with an Xp11.23p11.22 microduplication and review of the literature. Am J Med Genet A 2014; 167A:111-22. [PMID: 25425167 DOI: 10.1002/ajmg.a.36807] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 09/04/2014] [Indexed: 11/12/2022]
Abstract
Array comparative genomic hybridization (array CGH) has proven its utility in uncovering cryptic rearrangements in patients with X-linked intellectual disability. In 2009, Giorda et al. identified inherited and de novo recurrent Xp11.23p11.22 microduplications in two males and six females from a wide cohort of patients presenting with syndromic intellectual disability. To date, 14 females and 5 males with an overlapping microduplication have been reported in the literature. To further characterize this emerging syndrome, we collected clinical and microarray data from 17 new patients, 10 females, and 7 males. The Xp11.23p11.2 microduplications detected by array CGH ranged in size from 331 Kb to 8.9 Mb. Five patients harbored 4.5 Mb recurrent duplications mediated by non-allelic homologous recombination between segmental duplications and 12 harbored atypical duplications. The chromosomal rearrangement occurred de novo in eight patients and was inherited in six affected males from three families. Patients shared several common major characteristics including moderate to severe intellectual disability, early onset of puberty, language impairment, and age related epileptic syndromes such as West syndrome and focal epilepsy with activation during sleep evolving in some patients to continuous spikes-and-waves during slow sleep. Atypical microduplications allowed us to identify minimal critical regions that might be responsible for specific clinical findings of the syndrome and to suggest possible candidate genes: FTSJ1 and SHROOM4 for intellectual disability along with PQBP1 and SLC35A2 for epilepsy. Xp11.23p11.22 microduplication is a recently-recognized syndrome associated with intellectual disability, epilepsy, and early onset of puberty in females. In this study, we propose several genes that could contribute to the phenotype.
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Affiliation(s)
- Mathilde Nizon
- Département de Génétique, Université Paris Descartes, Sorbonne Paris Cité, Institut IMAGINE UMR_S1163, Hôpital Necker-Enfants Malades, Paris, France
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23
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Das D, Zalewski JK, Mohan S, Plageman TF, VanDemark AP, Hildebrand JD. The interaction between Shroom3 and Rho-kinase is required for neural tube morphogenesis in mice. Biol Open 2014; 3:850-60. [PMID: 25171888 PMCID: PMC4163662 DOI: 10.1242/bio.20147450] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Shroom3 is an actin-associated regulator of cell morphology that is required for neural tube closure, formation of the lens placode, and gut morphogenesis in mice and has been linked to chronic kidney disease and directional heart looping in humans. Numerous studies have shown that Shroom3 likely regulates these developmental processes by directly binding to Rho-kinase and facilitating the assembly of apically positioned contractile actomyosin networks. We have characterized the molecular basis for the neural tube defects caused by an ENU-induced mutation that results in an arginine-to-cysteine amino acid substitution at position 1838 of mouse Shroom3. We show that this substitution has no effect on Shroom3 expression or localization but ablates Rock binding and renders Shroom3 non-functional for the ability to regulate cell morphology. Our results indicate that Rock is the major downstream effector of Shroom3 in the process of neural tube morphogenesis. Based on sequence conservation and biochemical analysis, we predict that the Shroom-Rock interaction is highly conserved across animal evolution and represents a signaling module that is utilized in a variety of biological processes.
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Affiliation(s)
- Debamitra Das
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jenna K Zalewski
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Swarna Mohan
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Timothy F Plageman
- College of Optometry, The Ohio State University, Columbus, OH 43210, USA
| | - Andrew P VanDemark
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jeffrey D Hildebrand
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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24
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Ito K, Yamazaki S, Yamamoto R, Tajima Y, Yanagida A, Kobayashi T, Kato-Itoh M, Kakuta S, Iwakura Y, Nakauchi H, Kamiya A. Gene targeting study reveals unexpected expression of brain-expressed X-linked 2 in endocrine and tissue stem/progenitor cells in mice. J Biol Chem 2014; 289:29892-911. [PMID: 25143383 DOI: 10.1074/jbc.m114.580084] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Identification of genes specifically expressed in stem/progenitor cells is an important issue in developmental and stem cell biology. Genome-wide gene expression analyses in liver cells performed in this study have revealed a strong expression of X-linked genes that include members of the brain-expressed X-linked (Bex) gene family in stem/progenitor cells. Bex family genes are expressed abundantly in the neural cells and have been suggested to play important roles in the development of nervous tissues. However, the physiological role of its individual members and the precise expression pattern outside the nervous system remain largely unknown. Here, we focused on Bex2 and examined its role and expression pattern by generating knock-in mice; the enhanced green fluorescence protein (EGFP) was inserted into the Bex2 locus. Bex2-deficient mice were viable and fertile under laboratory growth conditions showing no obvious phenotypic abnormalities. Through an immunohistochemical analysis and flow cytometry-based approach, we observed unique EGFP reporter expression patterns in endocrine and stem/progenitor cells of the liver, pyloric stomach, and hematopoietic system. Although Bex2 seems to play redundant roles in vivo, these results suggest the significance and potential applications of Bex2 in studies of endocrine and stem/progenitor cells.
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Affiliation(s)
- Keiichi Ito
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
| | - Satoshi Yamazaki
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
| | - Ryo Yamamoto
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan, the Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305, and
| | - Yoko Tajima
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
| | - Ayaka Yanagida
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
| | - Toshihiro Kobayashi
- the NAKAUCHI Stem Cell and Organ Regeneration Project, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-8666, Japan, the Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, United Kingdom
| | - Megumi Kato-Itoh
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan, the NAKAUCHI Stem Cell and Organ Regeneration Project, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-8666, Japan
| | - Shigeru Kakuta
- the Department of Biomedical Science, Graduate School of Agriculture and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yoichiro Iwakura
- the Center for Animal Disease Models, Research Institute for Biomedical Sciences, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan
| | - Hiromitsu Nakauchi
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan, the Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California 94305, and the NAKAUCHI Stem Cell and Organ Regeneration Project, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-8666, Japan
| | - Akihide Kamiya
- From the Division of Stem Cell Therapy, Center for Stem Cell and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan, the Laboratory of Stem Cell Therapy, Institute of Innovative Science and Technology, Tokai University, 143 Shimokasuya, Isehara, Kanagawa 259-1143, Japan
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Wang J, Wang X, Guan T, Xiang Q, Wang M, Zhang Z, Guan Z, Wang G, Zhu Z, Xie Q, Li G, Guo J, Wang F, Zhang Z, Niu B, Zhang T. Analyses of copy number variation reveal putative susceptibility loci in MTX-induced mouse neural tube defects. Dev Neurobiol 2014; 74:877-93. [DOI: 10.1002/dneu.22170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 01/12/2014] [Accepted: 02/05/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Jianhua Wang
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Xiuwei Wang
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Tao Guan
- Department of Biochemistry and Molecular Biology; Shanxi Medical University; Taiyuan 030001 China
| | - Qian Xiang
- Department of Biomedical Engineering, Chinese Academy of Medical Sciences; Peking Union Medical College; Beijing 100730 China
| | - Mingsheng Wang
- Department of Biomedical Engineering, Chinese Academy of Medical Sciences; Peking Union Medical College; Beijing 100730 China
| | - Zhi Zhang
- Department of Biomedical Engineering, Chinese Academy of Medical Sciences; Peking Union Medical College; Beijing 100730 China
| | - Zhen Guan
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Guoliang Wang
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Zhiqiang Zhu
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Qiu Xie
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Guannan Li
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Jin Guo
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Fang Wang
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
| | - Zhengguo Zhang
- Department of Biomedical Engineering, Chinese Academy of Medical Sciences; Peking Union Medical College; Beijing 100730 China
| | - Bo Niu
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
- Department of Biochemistry and Molecular Biology; Shanxi Medical University; Taiyuan 030001 China
| | - Ting Zhang
- Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics; Capital Institute of Pediatrics; Beijing 100020 China
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Chen B, Brinkmann K, Chen Z, Pak CW, Liao Y, Shi S, Henry L, Grishin NV, Bogdan S, Rosen MK. The WAVE regulatory complex links diverse receptors to the actin cytoskeleton. Cell 2014; 156:195-207. [PMID: 24439376 DOI: 10.1016/j.cell.2013.11.048] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 09/06/2013] [Accepted: 11/25/2013] [Indexed: 02/02/2023]
Abstract
The WAVE regulatory complex (WRC) controls actin cytoskeletal dynamics throughout the cell by stimulating the actin-nucleating activity of the Arp2/3 complex at distinct membrane sites. However, the factors that recruit the WRC to specific locations remain poorly understood. Here, we have identified a large family of potential WRC ligands, consisting of ∼120 diverse membrane proteins, including protocadherins, ROBOs, netrin receptors, neuroligins, GPCRs, and channels. Structural, biochemical, and cellular studies reveal that a sequence motif that defines these ligands binds to a highly conserved interaction surface of the WRC formed by the Sra and Abi subunits. Mutating this binding surface in flies resulted in defects in actin cytoskeletal organization and egg morphology during oogenesis, leading to female sterility. Our findings directly link diverse membrane proteins to the WRC and actin cytoskeleton and have broad physiological and pathological ramifications in metazoans.
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Affiliation(s)
- Baoyu Chen
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Klaus Brinkmann
- Institut für Neurobiologie, Universität Münster, 48149 Münster, Germany
| | - Zhucheng Chen
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Chi W Pak
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Yuxing Liao
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Shuoyong Shi
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Lisa Henry
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Nick V Grishin
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Sven Bogdan
- Institut für Neurobiologie, Universität Münster, 48149 Münster, Germany.
| | - Michael K Rosen
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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27
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Mohan S, Das D, Bauer RJ, Heroux A, Zalewski JK, Heber S, Dosunmu-Ogunbi AM, Trakselis MA, Hildebrand JD, VanDemark AP. Structure of a highly conserved domain of Rock1 required for Shroom-mediated regulation of cell morphology. PLoS One 2013; 8:e81075. [PMID: 24349032 PMCID: PMC3857177 DOI: 10.1371/journal.pone.0081075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 10/08/2013] [Indexed: 01/07/2023] Open
Abstract
Rho-associated coiled coil containing protein kinase (Rho-kinase or Rock) is a well-defined determinant of actin organization and dynamics in most animal cells characterized to date. One of the primary effectors of Rock is non-muscle myosin II. Activation of Rock results in increased contractility of myosin II and subsequent changes in actin architecture and cell morphology. The regulation of Rock is thought to occur via autoinhibition of the kinase domain via intramolecular interactions between the N-terminus and the C-terminus of the kinase. This autoinhibited state can be relieved via proteolytic cleavage, binding of lipids to a Pleckstrin Homology domain near the C-terminus, or binding of GTP-bound RhoA to the central coiled-coil region of Rock. Recent work has identified the Shroom family of proteins as an additional regulator of Rock either at the level of cellular distribution or catalytic activity or both. The Shroom-Rock complex is conserved in most animals and is essential for the formation of the neural tube, eye, and gut in vertebrates. To address the mechanism by which Shroom and Rock interact, we have solved the structure of the coiled-coil region of Rock that binds to Shroom proteins. Consistent with other observations, the Shroom binding domain is a parallel coiled-coil dimer. Using biochemical approaches, we have identified a large patch of residues that contribute to Shrm binding. Their orientation suggests that there may be two independent Shrm binding sites on opposing faces of the coiled-coil region of Rock. Finally, we show that the binding surface is essential for Rock colocalization with Shroom and for Shroom-mediated changes in cell morphology.
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Affiliation(s)
- Swarna Mohan
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Debamitra Das
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Robert J. Bauer
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Annie Heroux
- Department of Biology, Brookhaven National Laboratory, Upton, New York, United States of America
| | - Jenna K. Zalewski
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Simone Heber
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Atinuke M. Dosunmu-Ogunbi
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Michael A. Trakselis
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jeffrey D. Hildebrand
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (JDH); (AV)
| | - Andrew P. VanDemark
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (JDH); (AV)
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28
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Piton A, Redin C, Mandel JL. XLID-causing mutations and associated genes challenged in light of data from large-scale human exome sequencing. Am J Hum Genet 2013; 93:368-83. [PMID: 23871722 DOI: 10.1016/j.ajhg.2013.06.013] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 05/29/2013] [Accepted: 06/08/2013] [Indexed: 12/30/2022] Open
Abstract
Because of the unbalanced sex ratio (1.3-1.4 to 1) observed in intellectual disability (ID) and the identification of large ID-affected families showing X-linked segregation, much attention has been focused on the genetics of X-linked ID (XLID). Mutations causing monogenic XLID have now been reported in over 100 genes, most of which are commonly included in XLID diagnostic gene panels. Nonetheless, the boundary between true mutations and rare non-disease-causing variants often remains elusive. The sequencing of a large number of control X chromosomes, required for avoiding false-positive results, was not systematically possible in the past. Such information is now available thanks to large-scale sequencing projects such as the National Heart, Lung, and Blood (NHLBI) Exome Sequencing Project, which provides variation information on 10,563 X chromosomes from the general population. We used this NHLBI cohort to systematically reassess the implication of 106 genes proposed to be involved in monogenic forms of XLID. We particularly question the implication in XLID of ten of them (AGTR2, MAGT1, ZNF674, SRPX2, ATP6AP2, ARHGEF6, NXF5, ZCCHC12, ZNF41, and ZNF81), in which truncating variants or previously published mutations are observed at a relatively high frequency within this cohort. We also highlight 15 other genes (CCDC22, CLIC2, CNKSR2, FRMPD4, HCFC1, IGBP1, KIAA2022, KLF8, MAOA, NAA10, NLGN3, RPL10, SHROOM4, ZDHHC15, and ZNF261) for which replication studies are warranted. We propose that similar reassessment of reported mutations (and genes) with the use of data from large-scale human exome sequencing would be relevant for a wide range of other genetic diseases.
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Affiliation(s)
- Amélie Piton
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7104, Institut National de la Santé et de la Recherche Médicale Unité 964, University of Strasbourg, 67404 Illkirch Cedex, France; Chaire de Génétique Humaine, Collège de France, 75231 Paris Cedex 05, France.
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Sporadic male patients with intellectual disability: contribution of X-chromosome copy number variants. Eur J Med Genet 2012; 55:577-85. [PMID: 22659343 DOI: 10.1016/j.ejmg.2012.05.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 05/19/2012] [Accepted: 05/20/2012] [Indexed: 12/18/2022]
Abstract
Genome-wide array comparative genome hybridization has become the first in line diagnostic tool in the clinical work-up of patients presenting with intellectual disability. As a result, chromosome X-copy number variations are frequently being detected in routine diagnostics. We retrospectively reviewed genome wide array-CGH data in order to determine the frequency and nature of chromosome X-copy number variations (X-CNV) in a cohort of 2222 sporadic male patients with intellectual disability (ID) referred to us for diagnosis. In this cohort, 68 males were found to have at least one X-CNV (3.1%). However, correct interpretation of causality remains a challenging task, and is essential for proper counseling, especially when the CNV is inherited. On the basis of these data, earlier experience and literature data we designed and propose an algorithm that can be used to evaluate the clinical relevance of X-CNVs detected in sporadic male ID patients. Applied to our cohort, 19 male ID patients (0.85%) were found to carry a (likely) pathogenic X-CNV.
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Ishikawa T, Miyata S, Koyama Y, Yoshikawa K, Hattori T, Kumamoto N, Shingaki K, Katayama T, Tohyama M. Transient expression of Xpn, an XLMR protein related to neurite extension, during brain development and participation in neurite outgrowth. Neuroscience 2012; 214:181-91. [PMID: 22531377 DOI: 10.1016/j.neuroscience.2012.04.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 03/11/2012] [Accepted: 04/09/2012] [Indexed: 12/22/2022]
Abstract
KIAA2022 has been implicated as a gene responsible for expressing X-linked mental retardation (XLMR) proteins in humans. However, the functional role of KIAA2022 in the human brain remains unclear. Here, we revealed that depletion of Kiaa2022 inhibits neurite outgrowth of PC12 cells, indicating that the gene participates in neurite extension. Thus, we termed Kiaa2022 as an XLMR protein related to neurite extension (Xpn). Using the mouse brain as a model and ontogenetic analysis of Xpn by real-time PCR, we clearly demonstrated that Xpn is expressed transiently during the late embryonic and perinatal stages. In situ hybridization histochemistry further revealed that Xpn-expressing neurons could be categorized ontogenetically into three types. The first type showed transient expression of Xpn during development. The second type maximally expressed Xpn during the late embryonic or perinatal stage. Thereafter, Xpn expression in this type of neuron decreased gradually throughout development. Nevertheless, a significant level of Xpn expression was detected even into adulthood. The third type of neurons initiated expression of Xpn during the embryonic stage, and continued to express the gene throughout the remaining developmental stages. Subsequent immunohistochemical analysis revealed that Xpn was localized to the nucleus and cytoplasm throughout brain development. Our findings indicate that Xpn may participate in neural circuit formation during developmental stages via nuclear and cytoplasmic Xpn. Moreover, disturbances of this neuronal circuit formation may play a role in the pathogenesis of mental retardation.
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Affiliation(s)
- T Ishikawa
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
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31
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Mohan S, Rizaldy R, Das D, Bauer RJ, Heroux A, Trakselis MA, Hildebrand JD, VanDemark AP. Structure of Shroom domain 2 reveals a three-segmented coiled-coil required for dimerization, Rock binding, and apical constriction. Mol Biol Cell 2012; 23:2131-42. [PMID: 22493320 PMCID: PMC3364177 DOI: 10.1091/mbc.e11-11-0937] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Shroom (Shrm) proteins are essential regulators of cell shape and tissue morpho-logy during animal development that function by interacting directly with the coiled-coil region of Rho kinase (Rock). The Shrm-Rock interaction is sufficient to direct Rock subcellular localization and the subsequent assembly of contractile actomyosin networks in defined subcellular locales. However, it is unclear how the Shrm-Rock interaction is regulated at the molecular level. To begin investigating this issue, we present the structure of Shrm domain 2 (SD2), which mediates the interaction with Rock and is required for Shrm function. SD2 is a unique three-segmented dimer with internal symmetry, and we identify conserved residues on the surface and within the dimerization interface that are required for the Rock-Shrm interaction and Shrm activity in vivo. We further show that these residues are critical in both vertebrate and invertebrate Shroom proteins, indicating that the Shrm-Rock signaling module has been functionally and molecularly conserved. The structure and biochemical analysis of Shrm SD2 indicate that it is distinct from other Rock activators such as RhoA and establishes a new paradigm for the Rock-mediated assembly of contractile actomyosin networks.
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Affiliation(s)
- Swarna Mohan
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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32
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Assef YA, Ozu M, Marino GI, Galizia L, Kotsias BA. ENaC channels in oocytes from Xenopus laevis and their regulation by xShroom1 protein. Cell Physiol Biochem 2011; 28:259-66. [PMID: 21865733 DOI: 10.1159/000331738] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2011] [Indexed: 11/19/2022] Open
Abstract
Shroom is a family of related proteins linked to the actin cytoskeleton. xShroom1 is constitutively expressed in X. oocytes and is required for the expression of amiloride sensitive sodium channels (ENaC). Oocytes were injected with α, β, and γ mENaC and xShroom1 sense or antisense oligonucleotides. We used voltage clamp techniques to study the amiloride-sensitive Na(+) currents (INa((amil))). We observed a marked reduction in INa((amil)) in oocytes co-injected with xShroom1 antisense. Oocytes expressing a DEG mutant β-mENaC subunit (β-S518K) with an open probability of 1 had enhanced INa((amil)) although these currents were also reduced when co-injected with xShroom1 antisense. Addition of low concentration (20 ng/ml) of trypsin which activates the membrane-resident ENaC channels led to a slow increase in INa((amil)) in oocytes with xShroom1 sense but had no effect on the currents in oocytes coinjected with ENaC and xShroom1 antisense. The same results were obtained with higher concentrations of trypsin (2 μg/ml) exposed during 2.5 min. In addition, fluorescence positive staining of plasma membrane in the oocytes expressing α, β and γ mENaC and xShroom1 sense were observed but not in oocytes coinjected with ENaC and xShroom1 antisense oligonucleotides. On this basis, we suggest that xShroom1-dependent ENaC inhibition may be through the number of channels inserted in the membrane.
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Affiliation(s)
- Yanina A Assef
- Laboratorio de Canales Iónicos, Instituto de Investigaciones Médicas Alfredo Lanari, University of Buenos Aires, IDIM- CONICET, Buenos Aires, Argentina
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Kaufman L, Ayub M, Vincent JB. The genetic basis of non-syndromic intellectual disability: a review. J Neurodev Disord 2010; 2:182-209. [PMID: 21124998 PMCID: PMC2974911 DOI: 10.1007/s11689-010-9055-2] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 06/25/2010] [Indexed: 11/06/2022] Open
Abstract
Intellectual disability (ID), also referred to as mental retardation (MR), is frequently the result of genetic mutation. Where ID is present together with additional clinical symptoms or physical anomalies, there is often sufficient information available for the diagnosing physician to identify a known syndrome, which may then educe the identification of the causative defect. However, where co-morbid features are absent, narrowing down a specific gene can only be done by ‘brute force’ using the latest molecular genetic techniques. Here we attempt to provide a systematic review of genetic causes of cases of ID where no other symptoms or co-morbid features are present, or non-syndromic ID. We attempt to summarize commonalities between the genes and the molecular pathways of their encoded proteins. Since ID is a common feature of autism, and conversely autistic features are frequently present in individuals with ID, we also look at possible overlaps in genetic etiology with non-syndromic ID.
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34
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Honda S, Hayashi S, Imoto I, Toyama J, Okazawa H, Nakagawa E, Goto YI, Inazawa J. Copy-number variations on the X chromosome in Japanese patients with mental retardation detected by array-based comparative genomic hybridization analysis. J Hum Genet 2010; 55:590-9. [PMID: 20613765 DOI: 10.1038/jhg.2010.74] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
X-linked mental retardation (XLMR) is a common, clinically complex and genetically heterogeneous disease arising from many mutations along the X chromosome. Although research during the past decade has identified >90 XLMR genes, many more remain uncharacterized. In this study, copy-number variations (CNVs) were screened in individuals with MR from 144 families by array-based comparative genomic hybridization (aCGH) using a bacterial artificial chromosome-based X-tiling array. Candidate pathogenic CNVs (pCNVs) were detected in 10 families (6.9%). Five of the families had pCNVs involving known XLMR genes, duplication of Xq28 containing MECP2 in three families, duplication of Xp11.22-p11.23 containing FTSJ1 and PQBP1 in one family, and deletion of Xp11.22 bearing SHROOM4 in one family. New candidate pCNVs were detected in five families as follows: identical complex pCNVs involved in dup(X)(p22.2) and dup(X)(p21.3) containing part of REPS2, NHS and IL1RAPL1 in two unrelated families, duplication of Xp22.2 including part of FRMPD4, duplication of Xq21.1 including HDX and deletion of Xq24 noncoding region in one family, respectively. Both parents and only mother samples were available in six and three families, respectively, and pCNVs were inherited from each of their mothers in those families other than a family of the proband with deletion of SHROOM4. This study should help to identify the novel XLMR genes and mechanisms leading to MR and reveal the clinical conditions and genomic background of XLMR.
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Affiliation(s)
- Shozo Honda
- Department of Molecular Cytogenetics, Medical Research Institute and School of Biomedical Science, Tokyo Medical and Dental University, Tokyo, Japan
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Holden ST, Clarkson A, Thomas NS, Abbott K, James MR, Willatt L. A de novo duplication of Xp11.22-p11.4 in a girl with intellectual disability, structural brain anomalies, and preferential inactivation of the normal X chromosome. Am J Med Genet A 2010; 152A:1735-40. [DOI: 10.1002/ajmg.a.33457] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Yang F, Babak T, Shendure J, Disteche CM. Global survey of escape from X inactivation by RNA-sequencing in mouse. Genome Res 2010; 20:614-22. [PMID: 20363980 DOI: 10.1101/gr.103200.109] [Citation(s) in RCA: 278] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
X inactivation equalizes the dosage of gene expression between the sexes, but some genes escape silencing and are thus expressed from both alleles in females. To survey X inactivation and escape in mouse, we performed RNA sequencing in Mus musculus x Mus spretus cells with complete skewing of X inactivation, relying on expression of single nucleotide polymorphisms to discriminate allelic origin. Thirteen of 393 (3.3%) mouse genes had significant expression from the inactive X, including eight novel escape genes. We estimate that mice have significantly fewer escape genes compared with humans. Furthermore, escape genes did not cluster in mouse, unlike the large escape domains in human, suggesting that expression is controlled at the level of individual genes. Our findings are consistent with the striking differences in phenotypes between female mice and women with a single X chromosome--a near normal phenotype in mice versus Turner syndrome and multiple abnormalities in humans. We found that escape genes are marked by the absence of trimethylation at lysine 27 of histone H3, a chromatin modification associated with genes subject to X inactivation. Furthermore, this epigenetic mark is developmentally regulated for some mouse genes.
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Affiliation(s)
- Fan Yang
- Department of Pathology, University of Washington, Seattle, Washington 98195, USA
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Complex segmental duplications mediate a recurrent dup(X)(p11.22-p11.23) associated with mental retardation, speech delay, and EEG anomalies in males and females. Am J Hum Genet 2009; 85:394-400. [PMID: 19716111 DOI: 10.1016/j.ajhg.2009.08.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 07/31/2009] [Accepted: 08/05/2009] [Indexed: 11/22/2022] Open
Abstract
Submicroscopic copy-number variations make a considerable contribution to the genetic etiology of human disease. We have analyzed subjects with idiopathic mental retardation (MR) by using whole-genome oligonucleotide-based array comparative genomic hybridization (aCGH) and identified familial and de novo recurrent Xp11.22-p11.23 duplications in males and females with MR, speech delay, and a peculiar electroencephalographic (EEG) pattern in childhood. The size of the duplications ranges from 0.8-9.2 Mb. Most affected females show preferential activation of the duplicated X chromosome. Carriers of the smallest duplication show X-linked recessive inheritance. All other affected individuals present dominant expression and comparable clinical phenotypes irrespective of sex, duplication size, and X-inactivation pattern. The majority of the rearrangements are mediated by recombination between flanking complex segmental duplications. The identification of common clinical features, including the typical EEG pattern, predisposing genomic structure, and peculiar X-inactivation pattern, suggests that duplication of Xp11.22-p11.23 constitutes a previously undescribed syndrome.
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38
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Lee C, Le MP, Wallingford JB. The shroom family proteins play broad roles in the morphogenesis of thickened epithelial sheets. Dev Dyn 2009; 238:1480-91. [PMID: 19384856 PMCID: PMC2699254 DOI: 10.1002/dvdy.21942] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thickened epithelial sheets are found in a wide variety of organ systems and the mechanisms governing their morphogenesis remain poorly defined. We show here, through expression patterns and functional studies, that Shroom family proteins are broadly involved in generating thickened epithelial sheets. Through in situ hybridization, we report the temporal and spatial expression patterns of the four Shroom family members during early Xenopus development, from oocytes to tadpole stage embryos. Further, we show that Shroom1 and 2 mRNAs are maternally expressed, while Shroom3 and Shroom4 are zygotic transcripts. In addition, maternal Shroom1 and 2 mRNAs localize in the animal hemisphere of the Xenopus egg and early blastula. During later development, all four Shroom family proteins are broadly expressed in developing epithelial organs, and the epithelial cells that express Shrooms are elongated. Moreover, we show that ectopic expression of Shroom2, like Shroom3, is able to increase cell height and that loss of Shroom2 function results in a failure of cell elongation in the neural epithelium. Together, these data suggest that Shroom family proteins play an important role in the morphogenesis of several different epithelial tissues during development. Developmental Dynamics 238:1480-1491, 2009. (c) 2009 Wiley-Liss, Inc.
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Affiliation(s)
- Chanjae Lee
- Department of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA
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39
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Gécz J, Shoubridge C, Corbett M. The genetic landscape of intellectual disability arising from chromosome X. Trends Genet 2009; 25:308-16. [PMID: 19556021 DOI: 10.1016/j.tig.2009.05.002] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 05/14/2009] [Accepted: 05/14/2009] [Indexed: 01/07/2023]
Abstract
X-linked mental retardation (XLMR) or intellectual disability (ID) is a common, clinically complex and genetically heterogeneous disease arising from many mutations along the X chromosome. It affects between 1/600-1/1000 males and a substantial number of females. Research during the past decade has identified >90 different XLMR genes, affecting a wide range of cellular processes. Many more genes remain uncharacterized, especially for the non-syndromic XLMR forms. Currently, approximately 11% of X-chromosome genes are implicated in XLMR; however, apart from a few notable exceptions, most contribute individually to <0.1% of the total landscape, which arguably remains only about half complete. There remain many hills to climb and valleys to cross before the ID landscape is fully triangulated.
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Affiliation(s)
- Jozef Gécz
- Molecular Pathology, SA Pathology at Women's and Children's Hospital, North Adelaide, SA 5006, Australia
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40
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Cantagrel V, Haddad MR, Ciofi P, Andrieu D, Lossi AM, Maldergem LV, Roux JC, Villard L. Spatiotemporal expression in mouse brain of Kiaa2022, a gene disrupted in two patients with severe mental retardation. Gene Expr Patterns 2009; 9:423-9. [PMID: 19524067 DOI: 10.1016/j.gep.2009.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 05/13/2009] [Accepted: 06/06/2009] [Indexed: 10/20/2022]
Abstract
We previously identified an inactivating disruption of the X-linked KIAA2022 gene by a chromosomal rearrangement in two male patients with severe mental retardation. In order to determine if KIAA2022 has a role during the development of the central nervous system, we have cloned its murine ortholog, Kiaa2022, determined its genomic structure and studied its expression during mouse development. We show that Kiaa2022 is preferentially expressed in the central nervous system and that the transcript is highly expressed in postmitotic neurons. The expression of Kiaa2022 is first detectable at E10.5 to reach a maximum at P3 where it is notably expressed in the hippocampus, the entorhinal cortex and strongly in the ventral premammillary nucleus. After P3, the expression of Kiaa2022 decreases and maintains very low levels thereafter. Our results show that Kiaa2022 is expressed in the developing brain and that it may play a role in postmitotic, maturing neurons.
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41
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Balanced translocations in mental retardation. Hum Genet 2009; 126:133-47. [PMID: 19347365 DOI: 10.1007/s00439-009-0661-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2009] [Accepted: 03/23/2009] [Indexed: 12/13/2022]
Abstract
Over the past few decades, the knowledge on genetic defects causing mental retardation has dramatically increased. In this review, we discuss the importance of balanced chromosomal translocations in the identification of genes responsible for mental retardation. We present a database-search guided overview of balanced translocations identified in patients with mental retardation. We divide those in four categories: (1) balanced translocations that helped to identify a causative gene within a contiguous gene syndrome, (2) balanced translocations that led to the identification of a mental retardation gene confirmed by independent methods, (3) balanced translocations disrupting candidate genes that have not been confirmed by independent methods and (4) balanced translocations not reported to disrupt protein coding sequences. It can safely be concluded that balanced translocations have been instrumental in the identification of multiple genes that are involved in mental retardation. In addition, many more candidate genes were identified with a suspected but (as yet?) unconfirmed role in mental retardation. Some balanced translocations do not disrupt a protein coding gene and it can be speculated that in the light of recent findings concerning ncRNA's and ultra-conserved regions, such findings are worth further investigation as these potentially may lead us to the discovery of novel disease mechanisms.
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42
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Kalscheuer VM, Feenstra I, Van Ravenswaaij-Arts CMA, Smeets DFCM, Menzel C, Ullmann R, Musante L, Ropers HH. Disruption of the TCF4 gene in a girl with mental retardation but without the classical Pitt-Hopkins syndrome. Am J Med Genet A 2008; 146A:2053-9. [PMID: 18627065 DOI: 10.1002/ajmg.a.32419] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have characterized a de novo balanced translocation t(18;20)(q21.1;q11.2) in a female patient with mild to moderate mental retardation (MR) and minor facial anomalies. Breakpoint-mapping by fluorescence in situ hybridization indicated that on chromosome 18, the basic helix-loop-helix transcription factor TCF4 gene is disrupted by the breakpoint. TCF4 plays a role in cell fate determination and differentiation. Only recently, mutations in this gene have been shown to result in Pitt-Hopkins syndrome (PHS), defined by severe MR, epilepsy, mild growth retardation, microcephaly, daily bouts of hyperventilation starting in infancy, and distinctive facial features with deep-set eyes, broad nasal bridge, and wide mouth with widely spaced teeth. Breakpoint mapping on the derivative chromosome 20 indicated that here the rearrangement disrupted the chromodomain helicase DNA binding protein 6 (CHD6) gene. To date, there is no indication that CHD6 is involved in disease. Our study indicates that TCF4 gene mutations are not always associated with classical PHS but can give rise to a much milder clinical phenotype. Thus, the possibility exists that more patients with a less severe encephalopathy carry a mutation in this gene.
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Froyen G, Van Esch H, Bauters M, Hollanders K, Frints SGM, Vermeesch JR, Devriendt K, Fryns JP, Marynen P. Detection of genomic copy number changes in patients with idiopathic mental retardation by high-resolution X-array-CGH: important role for increased gene dosage of XLMR genes. Hum Mutat 2007; 28:1034-42. [PMID: 17546640 DOI: 10.1002/humu.20564] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A tiling X-chromosome-specific genomic array with a theoretical resolution of 80 kb was developed to screen patients with idiopathic mental retardation (MR) for submicroscopic copy number differences. Four patients with aberrations previously detected at lower resolution were first analyzed. This facilitated delineation of the location and extent of the aberration at high resolution and subsequently, more precise genotype-phenotype analyses. A cohort of 108 patients was screened, 57 of which were suspected of X-linked mental retardation (XLMR), 26 were probands of brother pairs, and 25 were sporadic cases. A total of 15 copy number changes in 14 patients (13%) were detected, which included two deletions and 13 duplications ranging from 0.1 to 2.7 Mb. The aberrations are associated with the phenotype in five patients (4.6%), based on the following criteria: de novo aberration; involvement of a known or candidate X-linked nonsyndromic(syndromic) MR (MRX(S)) gene; segregation with the disease in the family; absence in control individuals; and skewed X-inactivation in carrier females. These include deletions that contain the MRX(S) genes CDKL5, OPHN1, and CASK, and duplications harboring CDKL5, NXF5, MECP2, and GDI1. In addition, seven imbalances were apparent novel polymorphic regions because they do not fulfill the proposed criteria. Taken together, our data strongly suggest that not only deletions but also duplications on the X chromosome contribute to the phenotype more often than expected, supporting the increased gene dosage mechanism for deregulation of normal cognitive development.
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Affiliation(s)
- Guy Froyen
- Human Genome Laboratory, Department for Molecular and Developmental Genetics, VIB, Leuven, Belgium.
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Lee C, Scherr HM, Wallingford JB. Shroom family proteins regulate gamma-tubulin distribution and microtubule architecture during epithelial cell shape change. Development 2007; 134:1431-41. [PMID: 17329357 DOI: 10.1242/dev.02828] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cell shape changes require the coordination of actin and microtubule cytoskeletons. The molecular mechanisms by which such coordination is achieved remain obscure, particularly in the context of epithelial cells within developing vertebrate embryos. We have identified a novel role for the actin-binding protein Shroom3 as a regulator of the microtubule cytoskeleton during epithelial morphogenesis. We show that Shroom3 is sufficient and also necessary to induce a redistribution of the microtubule regulator gamma-tubulin. Moreover, this change in gamma-tubulin distribution underlies the assembly of aligned arrays of microtubules that drive apicobasal cell elongation. Finally, experiments with the related protein, Shroom1, demonstrate that gamma-tubulin regulation is a conserved feature of this protein family. Together, the data demonstrate that Shroom family proteins govern epithelial cell behaviors by coordinating the assembly of both microtubule and actin cytoskeletons.
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Affiliation(s)
- Chanjae Lee
- Department of Molecular Cell and Developmental Biology, and Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA
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Kalscheuer VM, FitzPatrick D, Tommerup N, Bugge M, Niebuhr E, Neumann LM, Tzschach A, Shoichet SA, Menzel C, Erdogan F, Arkesteijn G, Ropers HH, Ullmann R. Mutations in autism susceptibility candidate 2 (AUTS2) in patients with mental retardation. Hum Genet 2007; 121:501-9. [PMID: 17211639 DOI: 10.1007/s00439-006-0284-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Accepted: 10/16/2006] [Indexed: 01/11/2023]
Abstract
We report on three unrelated mentally disabled patients, each carrying a de novo balanced translocation that truncates the autism susceptibility candidate 2 (AUTS2) gene at 7q11.2. One of our patients shows relatively mild mental retardation; the other two display more profound disorders. One patient is also physically disabled, exhibiting urogenital and limb malformations in addition to severe mental retardation. The function of AUTS2 is presently unknown, but it has been shown to be disrupted in monozygotic twins with autism and mental retardation, both carrying a translocation t(7;20)(q11.2;p11.2) (de la Barra et al. in Rev Chil Pediatr 57:549-554, 1986; Sultana et al. in Genomics 80:129-134, 2002). Given the overlap of this autism/mental retardation (MR) phenotype and the MR-associated disorders in our patients, together with the fact that mapping of the additional autosomal breakpoints involved did not disclose obvious candidate disease genes, we ascertain with this study that AUTS2 mutations are clearly linked to autosomal dominant mental retardation.
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Affiliation(s)
- Vera M Kalscheuer
- Max-Planck-Institute for Molecular Genetics, Ihnestrasse 73, 14195, Berlin, Germany.
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Jensen LR, Lenzner S, Moser B, Freude K, Tzschach A, Wei C, Fryns JP, Chelly J, Turner G, Moraine C, Hamel B, Ropers HH, Kuss AW. X-linked mental retardation: a comprehensive molecular screen of 47 candidate genes from a 7.4 Mb interval in Xp11. Eur J Hum Genet 2006; 15:68-75. [PMID: 16969374 DOI: 10.1038/sj.ejhg.5201714] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
About 30% of the mutations causing nonsyndromic X-linked mental retardation (MRX) are thought to be located in Xp11 and in the pericentromeric region, with a particular clustering of gene defects in a 7.4 Mb interval flanked by the genes ELK1 and ALAS2. To search for these mutations, 47 brain-expressed candidate genes located in this interval have been screened for mutations in up to 22 mental retardation (MR) families linked to this region. In total, we have identified 57 sequence variants in exons and splice sites of 27 genes. Based on these data, four novel MR genes were identified, but most of the sequence variants observed during this study have not yet been described. The purpose of this article is to present a comprehensive overview of this work and its outcome. It describes all sequence variants detected in 548 exons and their flanking sequences, including disease-causing mutations as well as possibly relevant polymorphic and silent sequence changes. We show that many of the studied genes are unlikely to play a major role in MRX. This information will help to avoid duplication of efforts in the ongoing endeavor to unravel the molecular causes of MRX.
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Affiliation(s)
- Lars Riff Jensen
- Department of Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
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Hagens O, Ballabio A, Kalscheuer V, Kraehenbuhl JP, Schiaffino MV, Smith P, Staub O, Hildebrand J, Wallingford JB. A new standard nomenclature for proteins related to Apx and Shroom. BMC Cell Biol 2006; 7:18. [PMID: 16615870 PMCID: PMC1481537 DOI: 10.1186/1471-2121-7-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Accepted: 04/14/2006] [Indexed: 11/10/2022] Open
Abstract
Shroom is a recently-described regulator of cell shape changes in the developing nervous system. This protein is a member of a small family of related proteins that are defined by sequence similarity and in most cases by some link to the actin cytoskeleton. At present these proteins are named Shroom, APX, APXL, and KIAA1202. In light of the growing interest in this family of proteins, we propose here a new standard nomenclature.
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Affiliation(s)
- Olivier Hagens
- Dept. of Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | | | - Vera Kalscheuer
- Dept. of Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Jean-Pierre Kraehenbuhl
- Swiss Institute for Experimental Cancer Research and the Institute of Biochemistry, University of Lausanne, Lausanne, Switzerland
| | | | - Peter Smith
- Dept. of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Olivier Staub
- Dept. of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Jeff Hildebrand
- Dept. of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - John B Wallingford
- Dept. of Molecular Cell and Developmental Biology & Institute for Cellular and Molecular Biology, University of Texas, Austin, TX, USA
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Yoder M, Hildebrand JD. Shroom4 (Kiaa1202) is an actin-associated protein implicated in cytoskeletal organization. ACTA ACUST UNITED AC 2006; 64:49-63. [PMID: 17009331 DOI: 10.1002/cm.20167] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
All animal cells utilize a specialized set of cytoskeletal proteins to determine their overall shape and the organization of their intracellular compartments and organelles. During embryonic development, the dynamic nature of the actin cytoskeleton is critical for virtually all morphogenic events requiring changes in cell shape, migration, adhesion, and division. The behavior of the actin cytoskeleton is modulated by a myriad of accessory proteins. Shroom3 is an actin binding protein that regulates neural tube morphogenesis by eliciting changes in cell shape through a myosin II-dependent pathway. The Shroom-related gene SHROOM4 (formerly called KIAA1202) has also been implicated in neural development, as mutations in this gene are associated with human X-linked mental retardation. To better understand the function of Shrm4 in embryonic development, we have cloned mouse Shroom4 and characterized its protein product in vivo and in vitro. Shroom4 is expressed in a wide range of cell types during mouse development, including vascular endothelium and the polarized epithelium of the neural tube and kidney. In endothelial cells and embryo fibroblasts, endogenous Shroom4 co-distributes with myosin II to a distinct cytoplasmic population of F-actin and ectopic expression of Shroom4 in multiple cell types enhances or induces the formation of this actin-based structure. This localization is mediated, at least in part, by the direct interaction of Shroom4 and F-actin. Our results suggest that Shroom4 is a regulator of cytoskeletal architecture that may play an important role in vertebrate development.
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Affiliation(s)
- Michael Yoder
- Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
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Hagens O, Minina E, Schweiger S, Ropers HH, Kalscheuer V. Characterization of FBX25, encoding a novel brain-expressed F-box protein. Biochim Biophys Acta Gen Subj 2005; 1760:110-8. [PMID: 16278047 DOI: 10.1016/j.bbagen.2005.09.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Revised: 09/19/2005] [Accepted: 09/24/2005] [Indexed: 11/18/2022]
Abstract
F-box proteins (FBPs) confer substrate specificity to the SCF-type (Skp1/Cul1/FBP) of ubiquitin ligase complexes through their F-box. Multiple FBPs have been predicted, but experimental evidence is lagging. We report on the predicted human FBP hFBX25 which we found to be disrupted in a mentally retarded translocation carrier suffering from epileptic seizures. We investigated hFBX25's genomic organization and established hFBX25 as an FBP by verifying its interaction with Skp1 and Cul1. In the process, we identified an atypical serine residue in the F-box which is crucial for the hFBX25-Skp1 binding. We determined hFBX25's subcellular localization. We found strong transcription in human brain. In mouse embryonic sections, mFbx25 shows predominantly neuronal expression and in adult mouse brain, expression is confined to the hippocampus, the cerebral cortex and the Purkinje cell layer. Interestingly, aberrations in the ubiquitin pathway have been linked to neurological conditions.
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Affiliation(s)
- Olivier Hagens
- Max Planck Institute for Molecular Genetics, Department of Human Molecular Genetics, Ihnestr. 73, D-14195 Berlin, Germany
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