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Cukier HN, Duarte CL, Laverde-Paz MJ, Simon SA, Van Booven DJ, Miyares AT, Whitehead PL, Hamilton-Nelson KL, Adams LD, Carney RM, Cuccaro ML, Vance JM, Pericak-Vance MA, Griswold AJ, Dykxhoorn DM. An Alzheimer's disease risk variant in TTC3 modifies the actin cytoskeleton organization and the PI3K-Akt signaling pathway in iPSC-derived forebrain neurons. Neurobiol Aging 2023; 131:182-195. [PMID: 37677864 PMCID: PMC10538380 DOI: 10.1016/j.neurobiolaging.2023.07.007] [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: 05/25/2023] [Accepted: 07/11/2023] [Indexed: 09/09/2023]
Abstract
A missense variant in the tetratricopeptide repeat domain 3 (TTC3) gene (rs377155188, p.S1038C, NM_003316.4:c 0.3113C>G) was found to segregate with disease in a multigenerational family with late-onset Alzheimer's disease. This variant was introduced into induced pluripotent stem cells (iPSCs) derived from a cognitively intact individual using CRISPR genome editing, and the resulting isogenic pair of iPSC lines was differentiated into cortical neurons. Transcriptome analysis showed an enrichment for genes involved in axon guidance, regulation of actin cytoskeleton, and GABAergic synapse. Functional analysis showed that the TTC3 p.S1038C iPSC-derived neuronal progenitor cells had altered 3-dimensional morphology and increased migration, while the corresponding neurons had longer neurites, increased branch points, and altered expression levels of synaptic proteins. Pharmacological treatment with small molecules that target the actin cytoskeleton could revert many of these cellular phenotypes, suggesting a central role for actin in mediating the cellular phenotypes associated with the TTC3 p.S1038C variant.
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Affiliation(s)
- Holly N Cukier
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Carolina L Duarte
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Mayra J Laverde-Paz
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Shaina A Simon
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Derek J Van Booven
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Amanda T Miyares
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA; JJ Vance Memorial Summer Internship in Biological and Computational Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Patrice L Whitehead
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kara L Hamilton-Nelson
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Larry D Adams
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Regina M Carney
- Mental Health & Behavioral Science Service, Bruce W. Carter VA Medical Center, Miami, FL, USA
| | - Michael L Cuccaro
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA; John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jeffery M Vance
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Margaret A Pericak-Vance
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Anthony J Griswold
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA; John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Derek M Dykxhoorn
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA; John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA.
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2
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Cukier HN, Duarte CL, Laverde-Paz MJ, Simon SA, Van Booven DJ, Miyares AT, Whitehead PL, Hamilton-Nelson KL, Adams LD, Carney RM, Cuccaro ML, Vance JM, Pericak-Vance MA, Griswold AJ, Dykxhoorn DM. An Alzheimer's disease risk variant in TTC3 modifies the actin cytoskeleton organization and the PI3K-Akt signaling pathway in iPSC-derived forebrain neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542316. [PMID: 37292815 PMCID: PMC10246004 DOI: 10.1101/2023.05.25.542316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A missense variant in the tetratricopeptide repeat domain 3 ( TTC3 ) gene (rs377155188, p.S1038C, NM_003316.4:c.3113C>G) was found to segregate with disease in a multigenerational family with late onset Alzheimer's disease. This variant was introduced into induced pluripotent stem cells (iPSCs) derived from a cognitively intact individual using CRISPR genome editing and the resulting isogenic pair of iPSC lines were differentiated into cortical neurons. Transcriptome analysis showed an enrichment for genes involved in axon guidance, regulation of actin cytoskeleton, and GABAergic synapse. Functional analysis showed that the TTC3 p.S1038C iPSC-derived neuronal progenitor cells had altered 3D morphology and increased migration, while the corresponding neurons had longer neurites, increased branch points, and altered expression levels of synaptic proteins. Pharmacological treatment with small molecules that target the actin cytoskeleton could revert many of these cellular phenotypes, suggesting a central role for actin in mediating the cellular phenotypes associated with the TTC3 p.S1038C variant. Highlights The AD risk variant TTC3 p.S1038C reduces the expression levels of TTC3 The variant modifies the expression of AD specific genes BACE1 , INPP5F , and UNC5C Neurons with the variant are enriched for genes in the PI3K-Akt pathwayiPSC-derived neurons with the alteration have increased neurite length and branchingThe variant interferes with actin cytoskeleton and is ameliorated by Cytochalasin D.
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Hasina Z, Wang N, Wang CC. Developmental Neuropathology and Neurodegeneration of Down Syndrome: Current Knowledge in Humans. Front Cell Dev Biol 2022; 10:877711. [PMID: 35676933 PMCID: PMC9168127 DOI: 10.3389/fcell.2022.877711] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/18/2022] [Indexed: 12/25/2022] Open
Abstract
Individuals with Down syndrome (DS) suffer from developmental delay, intellectual disability, and an early-onset of neurodegeneration, Alzheimer’s-like disease, or precocious dementia due to an extra chromosome 21. Studying the changes in anatomical, cellular, and molecular levels involved may help to understand the pathogenesis and develop target treatments, not just medical, but also surgical, cell and gene therapy, etc., for individuals with DS. Here we aim to identify key neurodevelopmental manifestations, locate knowledge gaps, and try to build molecular networks to better understand the mechanisms and clinical importance. We summarize current information about the neuropathology and neurodegeneration of the brain from conception to adulthood of foetuses and individuals with DS at anatomical, cellular, and molecular levels in humans. Understanding the alterations and characteristics of developing Down syndrome will help target treatment to improve the clinical outcomes. Early targeted intervention/therapy for the manifestations associated with DS in either the prenatal or postnatal period may be useful to rescue the neuropathology and neurodegeneration in DS.
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Affiliation(s)
- Zinnat Hasina
- Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Nicole Wang
- School of Veterinary Medicine, Glasgow University, Glasgow, United Kingdom
| | - Chi Chiu Wang
- Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- Li Ka Shing Institute of Health Sciences, School of Biomedical Sciences, Chinese University of Hong Kong -Sichuan University Joint Laboratory in Reproductive Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- *Correspondence: Chi Chiu Wang,
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4
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Zhou X, Chen X, Hong T, Zhang M, Cai Y, Cui L. TTC3-Mediated Protein Quality Control, A Potential Mechanism for Cognitive Impairment. Cell Mol Neurobiol 2021; 42:1659-1669. [PMID: 33638766 PMCID: PMC9239942 DOI: 10.1007/s10571-021-01060-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/11/2021] [Indexed: 01/14/2023]
Abstract
The tetrapeptide repeat domain 3 (TTC3) gene falls within Down's syndrome (DS) critical region. Cognitive impairment is a common phenotype of DS and Alzheimer’s disease (AD), and overexpression of TTC3 can accelerate cognitive decline, but the specific mechanism is unknown. The TTC3-mediated protein quality control (PQC) mechanism, similar to the PQC system, is divided into three parts: it acts as a cochaperone to assist proteins in folding correctly; it acts as an E3 ubiquitin ligase (E3s) involved in protein degradation processes through the ubiquitin–proteasome system (UPS); and it may also eventually cause autophagy by affecting mitochondrial function. Thus, this article reviews the research progress on the structure, function, and metabolism of TTC3, including the recent research progress on TTC3 in DS and AD; the role of TTC3 in cognitive impairment through PQC in combination with the abovementioned attributes of TTC3; and the potential targets of TTC3 in the treatment of such diseases.
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Affiliation(s)
- Xu Zhou
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Xiongjin Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Tingting Hong
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Miaoping Zhang
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Yujie Cai
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Lili Cui
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China.
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Gong Y, Wang K, Xiao SP, Mi P, Li W, Shang Y, Dou F. Overexpressed TTC3 Protein Tends to be Cleaved into Fragments and Form Aggregates in the Nucleus. Neuromolecular Med 2019; 21:85-96. [PMID: 30203323 DOI: 10.1007/s12017-018-8509-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/31/2018] [Indexed: 12/01/2022]
Abstract
Human tetratricopeptide repeat domain 3 (TTC3) is a gene on 21q22.2 within the Down syndrome critical region (DSCR). Earlier studies suggest that TTC3 may be an important regulator in individual development, especially in neural development. As an E3 ligase, TTC3 binds to phosphorylated Akt and silence its activity via proteasomal cascade. Several groups also reported the involvement of TTC3 in familial Alzheimer's disease recently. In addition, our previous work shows that TTC3 also regulates the degradation of DNA polymerase gamma and over-expressed TTC3 protein tends to form insoluble aggregates in cells. In this study, we focus on the solubility and intracellular localization of TTC3 protein. Over-expressed TTC3 tends to form insoluble aggregates over time. The proteasome inhibitor MG132 treatment resulted in more TTC3 aggregates in a short period of time. We fused the fluorescent protein to either terminus of the TTC3 protein and found that the intracellular localization of fluorescent signals are different between the N-terminal tagged and C-terminal tagged proteins. Western blotting revealed that the TTC3 protein is cleaved into fragments of different sizes at multiple sites. The N-terminal sub-fragments of TTC3 are prone to from nuclear aggregates and the TTC3 nuclear import is mediated by signals within the N-terminal 1 to 650 residues. Moreover, over-expressed TTC3 induced a considerable degree of cytotoxicity, and its N-terminal sub-fragments are more potent inhibitors of cell proliferation than full-length protein. Considering the prevalent proteostasis dysregulation in neurodegenerative diseases, these findings may relate to the pathology of such diseases.
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Affiliation(s)
- Yueqing Gong
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Kun Wang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Sheng-Ping Xiao
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Panying Mi
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Wanjie Li
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Yu Shang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Fei Dou
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China.
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China.
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Gong Y, Wang X, Shang X, Xiao SP, Li W, Shang Y, Dou F. Tetratricopeptide repeat domain 3 overexpression tends to form aggregates and inhibit ubiquitination and degradation of DNA polymerase γ. Oncotarget 2017; 8:106475-106485. [PMID: 29290964 PMCID: PMC5739749 DOI: 10.18632/oncotarget.22476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 10/28/2017] [Indexed: 11/25/2022] Open
Abstract
Tetratricopeptide repeat (TPR) domain 3 (TTC3) is a protein that contains canonical RING finger and TPR motifs. It is encoded by the TTC3 gene located in the Down syndrome critical region (DSCR). In this study, we used a yeast two-hybrid assay to identify several proteins that physically interact with TTC3, including heat shock proteins and DNA polymerase γ (POLG). When TTC3 was overexpressed in mammalian cells, the ubiquitination of POLG was inhibited and its degradation slowed. High TTC3 protein expression led to the development of intracellular TTC3 aggregates, which also contained POLG. Co-expression with Hsp70 or placing the TTC3 gene under control of an inducible promoter alleviated the aggregation and facilitated POLG degradation. As a result of POLG's effects on aging processes, we propose that a copy number variant of the TTC3 may contribute to Down syndrome pathogenesis.
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Affiliation(s)
- Yueqing Gong
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG, McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.,Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Xiaolan Wang
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG, McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.,Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Xuan Shang
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG, McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.,Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Sheng Ping Xiao
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG, McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.,Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Wanjie Li
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Yu Shang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Fei Dou
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG, McGovern Institute for Brain Research, College of Life Sciences, Beijing Normal University, Beijing, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.,Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
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Bernardini C, Lattanzi W, Bosco P, Franceschini C, Plazzi G, Michetti F, Ferri R. Genome-wide gene expression profiling of human narcolepsy. Gene Expr 2012; 15:171-81. [PMID: 22783726 PMCID: PMC6043843 DOI: 10.3727/105221612x13372578119652] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The objective of this study was to perform global gene expression profiling of patients affected by narcolepsy with cataplexy (NRLCP). This enabled identifying new potential biomarkers and relevant molecules possibly involved in the disease pathogenesis. In this study 10 NRLCP patients and 10 healthy controls were compared. Total RNA isolated from blood specimens was analyzed using microarray technology followed by statistical data analysis to detect genome-wide differential gene expression between patients and controls. Functional analysis of the gene list was performed in order to interpret the biological significance of the data. One hundred and seventy-three genes showed significant (p < 0.01) differential expression between the two tested conditions. The biological interpretation allowed categorizing differentially expressed genes involved in neurite outgrowth/extension and brain development, which could be possibly regarded as peripheral markers of the disease. Moreover, the NRLCP-related gene expression profiles indicated a dysregulation of metabolic and immune-related mechanisms. In conclusion, the gene expression profile associated to NRLCP suggested that molecular markers of neurological impairment, dysmetabolic and immune-related mechanisms, can be detected in blood of NRLCP patients.
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Affiliation(s)
- Camilla Bernardini
- Institute of Anatomy and Cell Biology, Catholic University, Rome, Italy.
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Rachidi M, Lopes C. Molecular and cellular mechanisms elucidating neurocognitive basis of functional impairments associated with intellectual disability in Down syndrome. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2010; 115:83-112. [PMID: 20441388 DOI: 10.1352/1944-7558-115.2.83] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2008] [Accepted: 11/05/2009] [Indexed: 05/29/2023]
Abstract
Down syndrome, the most common genetic cause of intellectual disability, is associated with brain disorders due to chromosome 21 gene overdosage. Molecular and cellular mechanisms involved in the neuromorphological alterations and cognitive impairments are reported herein in a global model. Recent advances in Down syndrome research have lead to the identification of altered molecular pathways involved in intellectual disability, such as Calcineurin/NFATs pathways, that are of crucial importance in understanding the molecular basis of intellectual disability pathogenesis in this syndrome. Potential treatments in mouse models of Down syndrome, including antagonists of NMDA or GABA(A) receptors, and microRNAs provide new avenues to develop treatments of intellectual disability. Nevertheless, understanding the links between molecular pathways and treatment strategies in human beings requires further research.
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Affiliation(s)
- Mohammed Rachidi
- University of Paris, Denis Diderot Laboratory of Genetic Dysregulation Models: Trisomy 21 and Hyperhomocysteinemia. Tour 54, Paris, France.
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9
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Suizu F, Hiramuki Y, Okumura F, Matsuda M, Okumura AJ, Hirata N, Narita M, Kohno T, Yokota J, Bohgaki M, Obuse C, Hatakeyama S, Obata T, Noguchi M. The E3 Ligase TTC3 Facilitates Ubiquitination and Degradation of Phosphorylated Akt. Dev Cell 2009; 17:800-10. [DOI: 10.1016/j.devcel.2009.09.007] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Revised: 08/22/2009] [Accepted: 09/21/2009] [Indexed: 10/20/2022]
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Rachidi M, Delezoide AL, Delabar JM, Lopes C. A quantitative assessment of gene expression (QAGE) reveals differential overexpression of DOPEY2, a candidate gene for mental retardation, in Down syndrome brain regions. Int J Dev Neurosci 2009; 27:393-8. [PMID: 19460634 DOI: 10.1016/j.ijdevneu.2009.02.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 01/30/2009] [Accepted: 02/03/2009] [Indexed: 11/25/2022] Open
Abstract
The brain alterations and mental retardation in Down syndrome are associated with overdosage of chromosome 21 genes. To shed light on the understanding of the molecular effect of this genetic overdosage, gene expression studies have crucial importance to quantify expression variations in Down syndrome tissues compared to normal ones. Herein, an in situ Quantitative Assessment of Gene Expression (QAGE) was used to quantify and statistically analyze, for the first time, DOPEY2 expression variations in different regions of the Down syndrome human fetal brains and to compare them to corresponding normal brains. DOPEY2, which is localized in the Down Syndrome Critical Region (DSCR) and is a candidate gene for neurological alterations in Down syndrome, showed a delimited regional and cellular expression pattern in the cortex, hippocampus and cerebellum, characterized by different transcriptional intensities in both normal and trisomic brains. DOPEY2 is overexpressed more than 50% (1.79-, 1.97- and 2.12-folds in the cortex, cerebellum and hippocampus, respectively), and showed statistically significant differences in the overexpression ratios in the three brain regions expressing DOPEY2. The demonstration of differential DOPEY2 expression and overexpression in human fetal brains suggests that this gene is submitted to a complex transcriptional control and could depend from other human chromosome 21 genes. Moreover, DOPEY2 overexpression in the brain regions, that are altered in Down syndrome patients and involved in learning and memory processes, is in agreement to the hypothesis that this gene plays a potential role in functional brain alterations and in the pathogenesis of mental retardation in Down syndrome. This new in situ QAGE approach allowed quantitative measurements of transcriptional changes and statistical evaluations of the expression and overexpression patterns of DOPEY2 at specific regions of the brain, which is a complementary approach to qRT-PCR and microarray for transcriptome study. Moreover, this approach could be a powerful tool to study the candidate chromosome 21 genes for Down syndrome and other pathologies caused by regionalized quantitative transcriptional alterations, for greater interpretation of functional processes driving gene expression.
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Affiliation(s)
- Mohammed Rachidi
- Laboratory of Genetic Dysregulation Models: Trisomy 21 and Hyperhomocysteinemia, EA 3508, University Paris 7-Denis Diderot, Paris, France.
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11
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Mental retardation and associated neurological dysfunctions in Down syndrome: a consequence of dysregulation in critical chromosome 21 genes and associated molecular pathways. Eur J Paediatr Neurol 2008; 12:168-82. [PMID: 17933568 DOI: 10.1016/j.ejpn.2007.08.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 08/19/2007] [Accepted: 08/21/2007] [Indexed: 12/11/2022]
Abstract
Down syndrome (DS), affecting 1/700 live births, is the major genetic cause of mental retardation (MR), a cognitive disorder with hard impact on public health. DS brain is characterized by a reduced cerebellar volume and number of granular cells, defective cortical lamination and reduced cortical neurons, malformed dendritic trees and spines, and abnormal synapses. These neurological alterations, also found in trisomic mouse models, result from gene-dosage effects of Human Chromosome 21 (HC21) on the expression of critical developmental genes. HC21 sequencing, mouse ortholog gene identification and DS mouse model generation lead to determine HC21 gene functions and the effects of protein-dosage alterations in neurodevelopmental and metabolic pathways in DS individuals. Trisomic brain transcriptome of DS patients and trisomic mouse models identified some molecular changes determined by gene-overdosage and associated dysregulation of some disomic gene expression in DS brains. These transcriptional variations cause developmental alterations in neural patterning and signal transduction pathways that may lead to defective neuronal circuits responsible for the pathogenesis of MR in DS. Recently, the first altered molecular pathway responsible of some DS phenotypes, including neurological and cognitive disorders has been identified. In this pathway, two critical HC21 genes (DYRK1A and DSCR1) act synergistically to control the phosphorylation levels of NFATc and NFATc-regulated gene expression. Interestingly, the NFATc mice show neurological dysfunctions similar to those seen in DS patients and trisomic mouse models. Treatment of DS mouse model Ts65Dn with GABA(A) antagonists allowed post-drug rescue of cognitive defects, indicating a hopeful direction in clinical therapies for MR in children with DS.
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12
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Rachidi M, Lopes C. Mental retardation in Down syndrome: From gene dosage imbalance to molecular and cellular mechanisms. Neurosci Res 2007; 59:349-69. [PMID: 17897742 DOI: 10.1016/j.neures.2007.08.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 08/02/2007] [Accepted: 08/10/2007] [Indexed: 11/25/2022]
Abstract
Down syndrome (DS), the most frequent genetic disorder leading to mental retardation (MR), is caused by three copies of human chromosome 21 (HC21). Trisomic and transgenic mouse models for DS allow genetic dissection of DS neurological and cognitive disorders in view to identify genes responsible for these phenotypes. The effects of the gene dosage imbalance on DS phenotypes are explained by two hypotheses: the "gene dosage effect" hypothesis claims that a DS critical region, containing a subset of dosage-sensitive genes, determines DS phenotypes, and the "amplified developmental instability" hypothesis holds that HC21 trisomy determines general alteration in developmental homeostasis. Transcriptome and expression studies showed different up- or down-expression levels of genes located on HC21 and the other disomic chromosomes. HC21 genes, characterized by their overexpression in brain regions affected in DS patients and by their contribution to neurological and cognitive defects when overexpressed in mouse models, are proposed herein as good candidates for MR. In this article, we propose a new molecular and cellular mechanism explaining MR pathogenesis in DS. In this model, gene dosage imbalance effects on transcriptional variations are described considering the nature of gene products and their functional relationships. These transcriptional variations may affect different aspects of neuronal differentiation and metabolism and finally, determine the brain neuropathologies and mental retardation in DS.
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13
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Berto G, Camera P, Fusco C, Imarisio S, Ambrogio C, Chiarle R, Silengo L, Di Cunto F. The Down syndrome critical region protein TTC3 inhibits neuronal differentiation via RhoA and Citron kinase. J Cell Sci 2007; 120:1859-67. [PMID: 17488780 DOI: 10.1242/jcs.000703] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Down syndrome critical region (DSCR) on Chromosome 21 contains many genes whose duplication may lead to the major phenotypic features of Down syndrome and especially the associated mental retardation. However, the functions of DSCR genes are mostly unknown and their possible involvement in key brain developmental events still largely unexplored. In this report we show that the protein TTC3, encoded by one of the main DSCR candidate genes, physically interacts with Citron kinase (CIT-K) and Citron N (CIT-N), two effectors of the RhoA small GTPase that have previously been involved in neuronal proliferation and differentiation. More importantly, we found that TTC3 levels can strongly affect the NGF-induced differentiation of PC12 cells, by a CIT-K-dependent mechanism. Indeed, TTC3 overexpression leads to strong inhibition of neurite extension, which can be reverted by CIT-K RNAi. Conversely, TTC3 knockdown stimulates neurite extension in the same cells. Finally, we find that Rho, but not Rho kinase, is required for TTC3 differentiation-inhibiting activity. Our results suggest that the TTC3-RhoA-CIT-K pathway could be a crucial determinant of in vivo neuronal development, whose hyperactivity may result in detrimental effects on the normal differentiation program.
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Affiliation(s)
- Gaia Berto
- Molecular Biotechnology Center, Department of Genetics, Biology and Biochemistry, University of Turin, Italy
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Rachidi M, Lopes C. Differential transcription ofBarhl1homeobox gene in restricted functional domains of the central nervous system suggests a role in brain patterning. Int J Dev Neurosci 2005; 24:35-44. [PMID: 16384683 DOI: 10.1016/j.ijdevneu.2005.11.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 11/02/2005] [Accepted: 11/14/2005] [Indexed: 10/25/2022] Open
Abstract
The mouse Barhl1 homeogene, member of the BarH subfamily, play a crucial role in the cerebellum development and its human ortholog BARHL1 has been proposed as a positional and functional candidate gene for the Joubert syndrome, a form of cerebellar ataxia. The Barhl1 expression has been demonstrated to be induced by the transcription factor Math1 involved in BMP responses. We isolated the mouse Barhl1 by screening of a cDNA library with the Xenopus Xvent-2, member of the BarH subfamily, which acts in the BMP4 pathway during embryonic patterning and neural plate differentiation. We studied the detailed Barhl1 expression pattern and showed its transcription in spatio-temporally and functionally restricted domains of the developing central nervous system (CNS). Using our new optical microscopy technology, we compare the transcript steady state level and cell density in the Barhl1-expressing regions. We found that Barhl1 was transcribed in superior and inferior colliculi in the dorsal mesencephalon at a relatively low transcriptional level. In the diencephalon, Barhl1 was found higher expressed first within the basal plate and later in the mammillary region. In the cerebellum, Barhl1 showed the highest transcriptional level restricted to the anterior and posterior rhombic lips giving rise to the external and internal cerebellar granular cells and to the deep nuclei. In the spinal cord, Barhl1 showed similar expression level than in the cerebellum and is delimited to a subset of dorsal interneurons. Therefore, our results indicated that Barhl1 homeodomain gene is exclusively transcribed in restricted CNS domain at differential transcription levels which suggest a highly regulated transcriptional mechanism. In addition, these regional and cellular specificities indicated that Barhl1 may be involved in the differentiation of the specific subsets of neuronal progenitors.
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Affiliation(s)
- Mohammed Rachidi
- Institut d'Embryologie Cellulaire et Moléculaire, CNRS UMR 7128, Collège de France, 94736 Nogent-sur-Marne, France.
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Lopes C, Delezoide AL, Delabar JM, Rachidi M. BARHL1 homeogene, the human ortholog of the mouse Barhl1 involved in cerebellum development, shows regional and cellular specificities in restricted domains of developing human central nervous system. Biochem Biophys Res Commun 2005; 339:296-304. [PMID: 16307728 DOI: 10.1016/j.bbrc.2005.11.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2005] [Accepted: 11/01/2005] [Indexed: 01/28/2023]
Abstract
The mouse homeobox gene Barhl1 plays a central role in cerebellum development and its expression is activated by the transcription factor Math1 which is involved in bone morphogenetic protein response pathways. We studied the human ortholog BARHL1 and we found that human, mouse, monkey, rat, and zebrafish orthologs were highly conserved and are members of the BarH homeogene family, containing Drosophila BarH1 and BarH2. The N-terminus of BARHL1 protein presents two FIL domains and an acidic domain rich in serine/threonine and proline, while the C-terminus contains a canonical proline-rich domain. Secondary structure analysis showed that outside the three helixes of the homeodomain, BARHL1 protein has essentially random coil structure. We isolated BARHL1 and defined its expression pattern in human embryonic and fetal central nervous system (CNS) and compared it to the mouse Barhl1 transcription. BARHL1 mRNA was found exclusively in the CNS restricted to p1-p4 prosomeres of the diencephalon, to the dorsal cells of the mesencephalon, to the dorsal dl1 sensory neurons of the spinal cord, and to the rhombic lips yielding the cerebellar anlage. Detailed analysis of BARHL1 expression in fetal cerebellar cell layers using our new optic microscopy technology showed BARHL1 expression in external and internal granular cells and also in mouse adult granular cells, in agreement to Barhl1 null mouse phenotype affecting the differentiation and migration of granular cells. These findings indicate that the regional and cellular specificities of BARHL1 transcriptional control well correspond to the mouse Barhl1 transcription and suggest a potential role of this gene in the differentiation of BARHL1-expressing neuronal progenitors involved in the pattern formation of human cerebral and cerebellar structures.
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Affiliation(s)
- Carmela Lopes
- EA 3508 Université Paris 7-Denis Diderot, Paris, France
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Rachidi M, Lopes C, Delezoide AL, Delabar JM. C21orf5, a human candidate gene for brain abnormalities and mental retardation in Down syndrome. Cytogenet Genome Res 2005; 112:16-22. [PMID: 16276086 DOI: 10.1159/000087509] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2005] [Accepted: 05/10/2005] [Indexed: 11/19/2022] Open
Abstract
Mental retardation represents the more invalidating pathological aspect of trisomy 21 and has a hard impact on public health. The dosage imbalance of chromosome 21 genes could be the cause of neurological alterations and mental retardation seen in Down syndrome. We studied C21orf5 that we have demonstrated to be overexpressed in Down syndrome tissues, as a candidate gene for trisomy 21. A new optical technology (Rachidi et al., 2000) was used to compare signal intensity and cell density in presumptive embryonic brain compartments, at their boundaries and in higher specialized brain centres during fetal lifespan. We showed a developmentally regulated transcriptional activity of C21orf5 and a regional and cellular specific distribution of gene transcripts during human embryonic and fetal development. A wide but differential expression was detected in the nervous system during embryogenesis with a relatively lower level in the forebrain than in the midbrain and hindbrain and the highest transcription intensity in the future cerebellum. This developmentally regulated expression is maintained during post-embryogenesis and evolves selectively in fetal cerebral, hippocampal and cerebellar areas. Differential and cellular specificity were detected in hippocampus with higher C21orf5 mRNA level in the pyramidal cells compared to granular cells of the dentate gyrus. The expression pattern detected in cortical and cerebellar structures correlates well to the altered cortical lamination and to the lower size of the cerebellum observed in Down syndrome patients. In addition, the patterned differential expression detected in the medial temporal-lobe system, including hippocampal formation and perirhinal cortex, working as control centres of the memory circuits and involved in cognitive processes and memory storage, also corresponds to abnormal brain regions seen in Down syndrome patients. The C21orf5 selective expression in the key brain structures for learning and memory suggests that C21orf5 overexpression could participate in mental retardation pathogenesis in Down syndrome patients.
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Affiliation(s)
- M Rachidi
- EA 3508 Université Denis Diderot, Paris, France. [corrected]
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Rachidi M, Lopes C, Charron G, Delezoide AL, Paly E, Bloch B, Delabar JM. Spatial and temporal localization during embryonic and fetal human development of the transcription factor SIM2 in brain regions altered in Down syndrome. Int J Dev Neurosci 2005; 23:475-84. [PMID: 15946822 DOI: 10.1016/j.ijdevneu.2005.05.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Revised: 03/14/2005] [Accepted: 05/03/2005] [Indexed: 11/17/2022] Open
Abstract
Human SIM2 is the ortholog of Drosophila single-minded (sim), a master regulator of neurogenesis and transcriptional factor controlling midline cell fate determination. We previously localized SIM2 in a chromosome 21 critical region for Down syndrome (DS). Here, we studied SIM2 gene using a new approach to provide insights in understanding of its potential role in human development. For the first time, we showed SIM2 spatial and temporal expression pattern during human central nervous system (CNS) development, from embryonic to fetal stages. Additional investigations were performed using a new optic microscopy technology to compare signal intensity and cell density [M. Rachidi, C. Lopes, S. Gassanova, P.M. Sinet, M. Vekemans, T. Attie, A.L. Delezoide, J.M. Delabar, Regional and cellular specificity of the expression of TPRD, the tetratricopeptide Down syndrome gene, during human embryonic development, Mech. Dev. 93 (2000) 189--193]. In embryonic stages, SIM2 was identified predominantly in restricted regions of CNS, in ventral part of D1/D2 diencephalic neuroepithelium, along the neural tube and in a few cell subsets of dorsal root ganglia. In fetal stages, SIM2 showed differential expression in pyramidal and granular cell layers of hippocampal formation, in cortical cells and in cerebellar external granular and Purkinje cell layers. SIM2 expression in embryonic and fetal brain could suggest a potential role in human CNS development, in agreement with Drosophila and mouse Sim mutant phenotypes and with the conservation of the Sim function in CNS development from Drosophila to Human. SIM2 expression in human fetal brain regions, which correspond to key structures for cognitive processes, correlates well with the behavioral phenotypes of Drosophila Sim mutants and transgenic mice overexpressing Sim2. In addition, SIM2-expressing brain regions correspond to the altered structures in DS patients. All together, these findings suggest a potential role of SIM2 in CNS development and indicate that SIM2 overexpression could participate to the pathogenesis of mental retardation in Down syndrome patients.
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Affiliation(s)
- Mohammed Rachidi
- EA 3508, Tour 54, E2-54-53, Case 7104, Université Denis Diderot, 2 Place Jussieu, 75251 Paris, France.
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Thiery E, Thomas S, Vacher S, Delezoide AL, Delabar JM, Créau N. Chromosome 21 KIR channels in brain development. ACTA ACUST UNITED AC 2004:105-15. [PMID: 15068243 DOI: 10.1007/978-3-7091-6721-2_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Two KIR (K+ Inwardly Rectifying) channel genes have been identified on chromosome 21, in a region associated with important phenotypic features of trisomy 21, including mental retardation: KIR3.2 (GIRK2) and KIR4.2. We analysed the expression of these channel genes in developing human and mouse brains to determine the possible role of the corresponding channels in brain development and function. KIR3.2, which has been extensively studied in the mouse, was found to be expressed in the human cerebellum during development. The KIR4.2 channel is expressed later in development in both mice and humans. We compared the expression of these channels in terms of RNA and protein levels and discussed the potential synergy and consequences of the overexpression of these channels in Down's syndrome brain development.
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Affiliation(s)
- E Thiery
- EA3508, Université Denis Diderot, Paris, France
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Albrecht M, Lengauer T. Survey on the PABC recognition motif PAM2. Biochem Biophys Res Commun 2004; 316:129-38. [PMID: 15003521 DOI: 10.1016/j.bbrc.2004.02.024] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2004] [Indexed: 10/26/2022]
Abstract
The PABP-interacting motif PAM2 has been identified in various eukaryotic proteins as an important binding site for the PABC domain. This domain is contained in homologs of the poly(A)-binding protein PABP and the ubiquitin-protein ligase HYD. Despite the importance of the PAM2 motif, a comprehensive analysis of its occurrence in different proteins has been missing. Using iterated sequence profile searches, we obtained an extensive list of proteins carrying the PAM2 motif. We discuss their functional context and domain architecture, which often consists of RNA-binding domains. Our list of PAM2 motif proteins includes eukaryotic homologs of eRF3/GSPT1/2, PAIP1/2, Tob1/2, Ataxin-2, RBP37, RBP1, Blackjack, HELZ, TPRD, USP10, ERD15, C1D4.14, and the viral protease P29. The identification of the PAM2 motif in as yet uncharacterized proteins can give valuable hints with respect to their cellular function and potential interaction partners and suggests further experimentation. It is also striking that the PAM2 motif appears to occur solely outside globular protein domains.
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Affiliation(s)
- Mario Albrecht
- Max-Planck-Institute for Informatics, Stuhlsatzenhausweg 85, Saarbrücken 66123, Germany.
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Lopes C, Chettouh Z, Delabar JM, Rachidi M. The differentially expressed C21orf5 gene in the medial temporal-lobe system could play a role in mental retardation in Down syndrome and transgenic mice. Biochem Biophys Res Commun 2003; 305:915-24. [PMID: 12767918 DOI: 10.1016/s0006-291x(03)00867-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mental retardation represents the more invalidating pathological aspect of Down syndrome, DS, and has a hard impact in public health. Modifications in DS brain, concerning abnormal size, neuronal differentiation, and cell density, cause changes in the neurophysiology and behavior of DS patients, and could be determined by dosage imbalance of genes localized in the DS critical region, DCR. Among these genes, C21orf5 showed high homology with Caenorhabditis elegans Pad1 involved in cellular differentiation and patterning. To shed light on C21orf5 role in DS, we performed molecular characterization of human and mouse orthologs, their spatio-temporal expression during development and in adult, and overexpression in DS and transgenic mice. C21orf5 was widely expressed early in embryogenesis in the nervous system. Later, its expression became differential and increased in mesencephalon and rhomboencephalon. This developmental expression profile evolves selectively in adult brain with higher signals in hippocampus, cerebellum, perirhinal, and entorhinal cortex, compared to the other cortical regions. Cellular specificity was detected in hippocampus with higher C21orf5 mRNA level in CA3 cells. Our findings appoint C21orf5 as candidate gene for mental retardation: Its overexpression in DS cells may contribute to gene imbalance in DS.Its specific expression in normal and its mirroring pattern in transgenic mice correspond to abnormal regions in DS patients and to neurological phenotype of transgenic mice. Altered cortical lamination in transgenic mice and the Pad1 ortholog function suggest a potential role of C21orf5 in cell differentiation. Its patterned differential expression in the medial temporal-lobe system, including hippocampal formation and perirhinal cortex involved in memory storage, and learning and memory defects in the transgenic mice suggest a specialized role for C21orf5 in cognitive processes. These evidences suggest that C21orf5 is an attractive candidate gene contributing to neurological alterations responsible for mental retardation in DS patients.
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Affiliation(s)
- Carmela Lopes
- CNRS 8090 UMR, Institut de Biologie de Lille, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, B.P. 447, 59021 Lille, France.
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