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Mahalingan KK, Grotjahn DA, Li Y, Lander GC, Zehr EA, Roll-Mecak A. Structural basis for α-tubulin-specific and modification state-dependent glutamylation. Nat Chem Biol 2024:10.1038/s41589-024-01599-0. [PMID: 38658656 DOI: 10.1038/s41589-024-01599-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 03/06/2024] [Indexed: 04/26/2024]
Abstract
Microtubules have spatiotemporally complex posttranslational modification patterns. Tubulin tyrosine ligase-like (TTLL) enzymes introduce the most prevalent modifications on α-tubulin and β-tubulin. How TTLLs specialize for specific substrate recognition and ultimately modification-pattern generation is largely unknown. TTLL6, a glutamylase implicated in ciliopathies, preferentially modifies tubulin α-tails in microtubules. Cryo-electron microscopy, kinetic analysis and single-molecule biochemistry reveal an unprecedented quadrivalent recognition that ensures simultaneous readout of microtubule geometry and posttranslational modification status. By binding to a β-tubulin subunit, TTLL6 modifies the α-tail of the longitudinally adjacent tubulin dimer. Spanning two tubulin dimers along and across protofilaments (PFs) ensures fidelity of recognition of both the α-tail and the microtubule. Moreover, TTLL6 reads out and is stimulated by glutamylation of the β-tail of the laterally adjacent tubulin dimer, mediating crosstalk between α-tail and β-tail. This positive feedback loop can generate localized microtubule glutamylation patterns. Our work uncovers general principles that generate tubulin chemical and topographic complexity.
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Affiliation(s)
- Kishore K Mahalingan
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Danielle A Grotjahn
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute La Jolla, La Jolla, CA, USA
| | - Yan Li
- Proteomics Core Facility, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute La Jolla, La Jolla, CA, USA
| | - Elena A Zehr
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.
- Biochemistry & Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD, USA.
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2
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Lin Y, Wang Y, Lai T, Teng J, Lin C, Ke C, Yu I, Lee H, Chan C, Tung C, Conrad DF, O'Bryan MK, Lin Y. Deleterious genetic changes in AGTPBP1 result in teratozoospermia with sperm head and flagella defects. J Cell Mol Med 2024; 28:e18031. [PMID: 37937809 PMCID: PMC10826451 DOI: 10.1111/jcmm.18031] [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: 04/20/2023] [Revised: 10/23/2023] [Accepted: 10/28/2023] [Indexed: 11/09/2023] Open
Abstract
Approximately 10%-15% of couples worldwide are infertile, and male factors account for approximately half of these cases. Teratozoospermia is a major cause of male infertility. Although various mutations have been identified in teratozoospermia, these can vary among ethnic groups. In this study, we performed whole-exome sequencing to identify genetic changes potentially causative of teratozoospermia. Out of seven genes identified, one, ATP/GTP Binding Protein 1 (AGTPBP1), was characterized, and three missense changes were identified in two patients (Affected A: p.Glu423Asp and p.Pro631Leu; Affected B: p.Arg811His). In those two cases, severe sperm head and tail defects were observed. Moreover, AGTPBP1 localization showed a fragmented pattern compared to control participants, with specific localization in the neck and annulus regions. Using murine models, we found that AGTPBP1 is localized in the manchette structure, which is essential for sperm structure formation. Additionally, in Agtpbp1-null mice, we observed sperm head and tail defects similar to those in sperm from AGTPBP1-mutated cases, along with abnormal polyglutamylation tubulin and decreasing △-2 tubulin levels. In this study, we established a link between genetic changes in AGTPBP1 and human teratozoospermia for the first time and identified the role of AGTPBP1 in deglutamination, which is crucial for sperm formation.
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Affiliation(s)
- Yu‐Hua Lin
- Division of Urology, Department of SurgeryCardinal Tien HospitalNew TaipeiTaiwan
- Department of ChemistryFu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Ya‐Yun Wang
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Tsung‐Hsuan Lai
- Department of Obstetrics and GynecologyCathay General HospitalTaipeiTaiwan
- School of Medicine, Fu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Jih‐Lung Teng
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Chi‐Wei Lin
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Chih‐Chun Ke
- Department of UrologyEn Chu Kong HospitalNew Taipei CityTaiwan
| | - I‐Shing Yu
- Laboratory Animal CenterCollege of Medicine, National Taiwan UniversityTaipeiTaiwan
| | - Hui‐Ling Lee
- Department of ChemistryFu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Chying‐Chyuan Chan
- Department of Obstetrics and GynecologyTaipei City Hospital, Zhongxing Branch and Branch for Women and ChildrenTaipeiTaiwan
| | - Chi‐Hua Tung
- Program of Artificial Intelligence & Information SecurityFu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Donald F. Conrad
- Division of Genetics, Oregon National Primate Research CenterBeavertonOregonUSA
| | - Moira K. O'Bryan
- School of BioSciences and Bio21 Institute, The University of MelbourneParkvilleVictoriaAustralia
| | - Ying‐Hung Lin
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic UniversityNew Taipei CityTaiwan
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Ashaat EA, Ahmed HA, Elaraby NM, Fayez A, Metwally AM, Mekkawy MK, Hussen DF, Ashaat NA, Elhossini RM, ElAwady HA, Abdelgawad RHA, Gammal ME, Al Kersh MA, Saleh DA. The Diagnostic Value of Whole-Exome Sequencing in a Spectrum of Rare Neurological Disorders Associated with Cerebellar Atrophy. Mol Neurobiol 2023:10.1007/s12035-023-03866-y. [PMID: 38153683 DOI: 10.1007/s12035-023-03866-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 12/08/2023] [Indexed: 12/29/2023]
Abstract
Several neurological disorders, neurodevelopmental disorders, and neurodegenerative disorders have a genetic element with various clinical presentations ranging from mild to severe presentation. Neurological disorders are rare multifactorial disorders characterized by dysfunction and degeneration of synapses, neurons, and glial cells which are essential for movement, coordination, muscle strength, sensation, and cognition. The cerebellum might be involved at any time, either during development and maturation or later in life. Herein, we describe a spectrum of NDDs and NDs in seven patients from six Egyptian families. The core clinical and radiological features of our patients included dysmorphic features, neurodevelopmental delay or regression, gait abnormalities, skeletal deformities, visual impairment, seizures, and cerebellar atrophy. Previously unreported clinical phenotypic findings were recorded. Whole-exome sequencing (WES) was performed followed by an in silico analysis of the detected genetic variants' effect on the protein structure. Three novel variants were identified in three genes MFSD8, AGTPBP1, and APTX, and other previously reported three variants have been detected in "TPP1, AGTPBP1, and PCDHGC4" genes. In this cohort, we described the detailed unique phenotypic characteristics given the identified genetic profile in patients with neurological "neurodevelopmental disorders and neurodegenerative disorders" disorders associated with cerebellar atrophy, hence expanding the mutational spectrum of such disorders.
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Affiliation(s)
- Engy A Ashaat
- Clinical Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt.
| | - Hoda A Ahmed
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Nesma M Elaraby
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Alaaeldin Fayez
- Molecular Genetics and Enzymology Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Ammal M Metwally
- Community Medicine Research Department, Medical Research and Clinical Studies Institute, National Research Centre, Cairo, Egypt
| | - Mona K Mekkawy
- Human Cytogenetic Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Dalia Farouk Hussen
- Human Cytogenetic Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | | | - Rasha M Elhossini
- Clinical Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | | | | | - Mona El Gammal
- Clinical Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | | | - Dina Amin Saleh
- Pediatric Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
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4
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McKenna ED, Sarbanes SL, Cummings SW, Roll-Mecak A. The Tubulin Code, from Molecules to Health and Disease. Annu Rev Cell Dev Biol 2023; 39:331-361. [PMID: 37843925 DOI: 10.1146/annurev-cellbio-030123-032748] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Microtubules are essential dynamic polymers composed of α/β-tubulin heterodimers. They support intracellular trafficking, cell division, cellular motility, and other essential cellular processes. In many species, both α-tubulin and β-tubulin are encoded by multiple genes with distinct expression profiles and functionality. Microtubules are further diversified through abundant posttranslational modifications, which are added and removed by a suite of enzymes to form complex, stereotyped cellular arrays. The genetic and chemical diversity of tubulin constitute a tubulin code that regulates intrinsic microtubule properties and is read by cellular effectors, such as molecular motors and microtubule-associated proteins, to provide spatial and temporal specificity to microtubules in cells. In this review, we synthesize the rapidly expanding tubulin code literature and highlight limitations and opportunities for the field. As complex microtubule arrays underlie essential physiological processes, a better understanding of how cells employ the tubulin code has important implications for human disease ranging from cancer to neurological disorders.
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Affiliation(s)
- Elizabeth D McKenna
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Stephanie L Sarbanes
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Steven W Cummings
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA
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5
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Manto M, Cendelin J, Strupp M, Mitoma H. Advances in cerebellar disorders: pre-clinical models, therapeutic targets, and challenges. Expert Opin Ther Targets 2023; 27:965-987. [PMID: 37768297 DOI: 10.1080/14728222.2023.2263911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 09/24/2023] [Indexed: 09/29/2023]
Abstract
INTRODUCTION Cerebellar ataxias (CAs) represent neurological disorders with multiple etiologies and a high phenotypic variability. Despite progress in the understanding of pathogenesis, few therapies are available so far. Closing the loop between preclinical studies and therapeutic trials is important, given the impact of CAs upon patients' health and the roles of the cerebellum in multiple domains. Because of a rapid advance in research on CAs, it is necessary to summarize the main findings and discuss future directions. AREAS COVERED We focus our discussion on preclinical models, cerebellar reserve, the therapeutic management of CAs, and suitable surrogate markers. We searched Web of Science and PubMed using keywords relevant to cerebellar diseases, therapy, and preclinical models. EXPERT OPINION There are many symptomatic and/or disease-modifying therapeutic approaches under investigation. For therapy development, preclinical studies, standardization of disease evaluation, safety assessment, and demonstration of clinical improvements are essential. Stage of the disease and the level of the cerebellar reserve determine the goals of the therapy. Deficits in multiple categories and heterogeneity of CAs may require disease-, stage-, and symptom-specific therapies. More research is needed to clarify how therapies targeting the cerebellum influence both basal ganglia and the cerebral cortex, poorly explored domains in CAs.
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Affiliation(s)
- Mario Manto
- Service des Neurosciences, University of Mons, Mons, Belgium
| | - Jan Cendelin
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Michael Strupp
- Department of Neurology and German Center for Vertigo and Balance Disorders, Ludwig Maximilians University, Munich, Germany
| | - Hiroshi Mitoma
- Department of Medical Education, Tokyo medical University, Tokyo, Japan
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Del Pilar C, Lebrón-Galán R, Pérez-Martín E, Pérez-Revuelta L, Ávila-Zarza CA, Alonso JR, Clemente D, Weruaga E, Díaz D. The Selective Loss of Purkinje Cells Induces Specific Peripheral Immune Alterations. Front Cell Neurosci 2021; 15:773696. [PMID: 34916910 PMCID: PMC8671039 DOI: 10.3389/fncel.2021.773696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/27/2021] [Indexed: 11/13/2022] Open
Abstract
The progression of neurodegenerative diseases is reciprocally associated with impairments in peripheral immune responses. We investigated different contexts of selective neurodegeneration to identify specific alterations of peripheral immune cells and, at the same time, discover potential biomarkers associated to this pathological condition. Consequently, a model of human cerebellar degeneration and ataxia -the Purkinje Cell Degeneration (PCD) mouse- has been employed, as it allows the study of different processes of selective neuronal death in the same animal, i.e., Purkinje cells in the cerebellum and mitral cells in the olfactory bulb. Infiltrated leukocytes were studied in both brain areas and compared with those from other standardized neuroinflammatory models obtained by administering either gamma radiation or lipopolysaccharide. Moreover, both myeloid and lymphoid splenic populations were analyzed by flow cytometry, focusing on markers of functional maturity and antigen presentation. The severity and type of neural damage and inflammation affected immune cell infiltration. Leukocytes were more numerous in the cerebellum of PCD mice, being located predominantly within those cerebellar layers mostly affected by neurodegeneration, in a completely different manner than the typical models of induced neuroinflammation. Furthermore, the milder degeneration of the olfactory bulb did not foster leukocyte attraction. Concerning the splenic analysis, in PCD mice we found: (1) a decreased percentage of several myeloid cell subsets, and (2) a reduced mean fluorescence intensity in those myeloid markers related to both antigen presentation and functional maturity. In conclusion, the selective degeneration of Purkinje cells triggers a specific effect on peripheral immune cells, fostering both attraction and functional changes. This fact endorses the employment of peripheral immune cell populations as concrete biomarkers for monitoring different neuronal death processes.
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Affiliation(s)
- Carlos Del Pilar
- INCyL, Institute for Neuroscience of Castile and Leon, Universidad de Salamanca, Salamanca, Spain.,IBSAL, Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - Rafael Lebrón-Galán
- Grupo de Neuroinmuno-Reparación, Hospital Nacional de Parapléjicos, Toledo, Spain.,SESCAM (Servicio de Salud de Castile-La-Mancha), Castilla-La Mancha, Spain
| | - Ester Pérez-Martín
- INCyL, Institute for Neuroscience of Castile and Leon, Universidad de Salamanca, Salamanca, Spain.,IBSAL, Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - Laura Pérez-Revuelta
- INCyL, Institute for Neuroscience of Castile and Leon, Universidad de Salamanca, Salamanca, Spain.,IBSAL, Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - Carmelo Antonio Ávila-Zarza
- IBSAL, Institute of Biomedical Research of Salamanca, Salamanca, Spain.,Applied Statistics Group, Department of Statistics, Universidad de Salamanca, Salamanca, Spain
| | - José Ramón Alonso
- INCyL, Institute for Neuroscience of Castile and Leon, Universidad de Salamanca, Salamanca, Spain.,IBSAL, Institute of Biomedical Research of Salamanca, Salamanca, Spain.,Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile
| | - Diego Clemente
- Grupo de Neuroinmuno-Reparación, Hospital Nacional de Parapléjicos, Toledo, Spain.,SESCAM (Servicio de Salud de Castile-La-Mancha), Castilla-La Mancha, Spain
| | - Eduardo Weruaga
- INCyL, Institute for Neuroscience of Castile and Leon, Universidad de Salamanca, Salamanca, Spain.,IBSAL, Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - David Díaz
- INCyL, Institute for Neuroscience of Castile and Leon, Universidad de Salamanca, Salamanca, Spain.,IBSAL, Institute of Biomedical Research of Salamanca, Salamanca, Spain
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Cao J, Ran L, Liu C, Li Z. Serum copper decrease and cerebellar atrophy in patients with nitrous oxide-induced subacute combined degeneration: two cases report. BMC Neurol 2021; 21:471. [PMID: 34863097 PMCID: PMC8643018 DOI: 10.1186/s12883-021-02496-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 11/17/2021] [Indexed: 11/10/2022] Open
Abstract
Background Subacute combined degeneration (SCD) is a neurological complication commonly associated with vitamin B12 deficiency. It can result from nitrous oxide (N2O) abuse and cause neuropsychiatric symptoms. However, there has been no literature regarding alterations of serum copper and cerebellum in SCD patients. Case presentation We reported two cases of young SCD patients with histories of N2O abuse. In these cases, elevated homocysteine, macrocytic anemia, spinal cord abnormalities, and peripheral nerve injuries were detected. In addition, decreased serum copper level and cerebellar atrophy were reported for the first time. The patients’ symptoms improved after withdrawal of N2O exposure and vitamin B12 supplements. Conclusion We reported two SCD cases with serum copper alteration and cerebellar atrophy after N2O abuse for the first time. These might be crucial complements to the diagnosis of SCD.
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Affiliation(s)
- Jie Cao
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Lusen Ran
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Chenchen Liu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhijun Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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Baltanás FC, Berciano MT, Santos E, Lafarga M. The Childhood-Onset Neurodegeneration with Cerebellar Atrophy (CONDCA) Disease Caused by AGTPBP1 Gene Mutations: The Purkinje Cell Degeneration Mouse as an Animal Model for the Study of this Human Disease. Biomedicines 2021; 9:biomedicines9091157. [PMID: 34572343 PMCID: PMC8464709 DOI: 10.3390/biomedicines9091157] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 12/20/2022] Open
Abstract
Recent reports have identified rare, biallelic damaging variants of the AGTPBP1 gene that cause a novel and documented human disease known as childhood-onset neurodegeneration with cerebellar atrophy (CONDCA), linking loss of function of the AGTPBP1 protein to human neurodegenerative diseases. CONDCA patients exhibit progressive cognitive decline, ataxia, hypotonia or muscle weakness among other clinical features that may be fatal. Loss of AGTPBP1 in humans recapitulates the neurodegenerative course reported in a well-characterised murine animal model harbouring loss-of-function mutations in the AGTPBP1 gene. In particular, in the Purkinje cell degeneration (pcd) mouse model, mutations in AGTPBP1 lead to early cerebellar ataxia, which correlates with the massive loss of cerebellar Purkinje cells. In addition, neurodegeneration in the olfactory bulb, retina, thalamus and spinal cord were also reported. In addition to neurodegeneration, pcd mice show behavioural deficits such as cognitive decline. Here, we provide an overview of what is currently known about the structure and functional role of AGTPBP1 and discuss the various alterations in AGTPBP1 that cause neurodegeneration in the pcd mutant mouse and humans with CONDCA. The sequence of neuropathological events that occur in pcd mice and the mechanisms governing these neurodegenerative processes are also reported. Finally, we describe the therapeutic strategies that were applied in pcd mice and focus on the potential usefulness of pcd mice as a promising model for the development of new therapeutic strategies for clinical trials in humans, which may offer potential beneficial options for patients with AGTPBP1 mutation-related CONDCA.
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Affiliation(s)
- Fernando C. Baltanás
- Lab.1, CIC-IBMCC, University of Salamanca-CSIC and CIBERONC, 37007 Salamanca, Spain;
- Correspondence: ; Tel.: +34-923294801
| | - María T. Berciano
- Department of Molecular Biology and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), University of Cantabria-IDIVAL, 39011 Santander, Spain;
| | - Eugenio Santos
- Lab.1, CIC-IBMCC, University of Salamanca-CSIC and CIBERONC, 37007 Salamanca, Spain;
| | - Miguel Lafarga
- Department of Anatomy and Cell Biology and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), University of Cantabria-IDIVAL, 39011 Santander, Spain;
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9
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Türay S, Eröz R, Başak AN. A novel pathogenic variant in the 3' end of the AGTPBP1 gene gives rise to neurodegeneration without cerebellar atrophy: an expansion of the disease phenotype? Neurogenetics 2021; 22:127-132. [PMID: 33909173 DOI: 10.1007/s10048-021-00643-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 04/20/2021] [Indexed: 11/28/2022]
Abstract
Childhood-onset neurodegeneration with cerebellar atrophy (CONDCA) is a recently described form of the large group of infantile hereditary lower motor neuron diseases (Teoh et al. 2017), resulting from biallelic damaging variants in the AGTPBP1 gene, first described by Shashi et al. in EMBO J 37(23):e100540, 2018. AGTPBP-related neurodegeneration is a severe neurodevelopmental disorder that progresses with global developmental delay and intellectual disability, often accompanied with peripheral nerve damage and lower motor degeneration and a fatal course in the early years of life. The encoded protein is ATP/GTP-Binding Protein1, also known as cytosolic carboxypeptidase 1 (CCP1) or nervous system nuclear protein induced by axotomy (NNA1). Here we report a consanguineous family with four offspring, two of whom are affected. The index patient is a 21-month-old male with global developmental delay and hypotonia. The proband's 17-year-old sister, diagnosed with cerebral palsy, had severe hypotonia accompanied by motor and cognitive retardation. WES analysis revealed a novel homozygous c.3293G > A variant in the AGTPBP1 gene with high pathogenicity scores. Targeted Sanger sequencing confirmed the variant in both affected children and in heterozygous form in the parents. The affected siblings present with hypotonia and motor and cognitive retardation, in line with the studies previously reported. However, in our patients, no signs of cerebellar atrophy in cranial MRI were present, so the acronym CONDCA is not applicable; lower motor neuron findings were also absent. The matching and distinguishing aspects of our patients will add to the present literature and expand our understanding of this rare genetic neurodegenerative disease of early childhood.
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Affiliation(s)
- Sevim Türay
- Department of Pediatric Neurology, Düzce University Medical Faculty, Duzce, 81820, Turkey.
| | - Recep Eröz
- Department of Medical Genetics, Düzce University Medical Faculty, Duzce, Turkey
| | - A Nazlı Başak
- Suna and İnan Kıraç Foundation, Neurodegeneration Research Laboratory, NDAL-KUTTAM, School of Medicine, Koç University, Istanbul, Turkey
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10
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Keller N, Paketci C, Altmueller J, Fuhrmann N, Wunderlich G, Schrank B, Unver O, Yilmaz S, Boostani R, Karimiani EG, Motameny S, Thiele H, Nürnberg P, Maroofian R, Yis U, Wirth B, Karakaya M. Genomic variants causing mitochondrial dysfunction are common in hereditary lower motor neuron disease. Hum Mutat 2021; 42:460-472. [PMID: 33600046 DOI: 10.1002/humu.24181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/29/2020] [Accepted: 02/10/2021] [Indexed: 11/08/2022]
Abstract
Hereditary lower motor neuron diseases (LMND) other than 5q-spinal muscular atrophy (5q-SMA) can be classified according to affected muscle groups. Proximal and distal forms of non-5q-SMA represent a clinically and genetically heterogeneous spectrum characterized by significant overlaps with axonal forms of Charcot-Marie-Tooth (CMT) disease. A consensus for the best approach to molecular diagnosis needs to be reached, especially in light of continuous novel gene discovery and falling costs of next-generation sequencing (NGS). We performed exome sequencing (ES) in 41 families presenting with non-5q-SMA or axonal CMT, 25 of which had undergone a previous negative neuromuscular disease (NMD) gene panel analysis. The total diagnostic yield of ES was 41%. Diagnostic success in the cohort with a previous NMD-panel analysis was significantly extended by ES, primarily due to novel gene associated-phenotypes and uncharacteristic phenotypic presentations. We recommend early ES for individuals with hereditary LMND presenting uncharacteristic or significantly overlapping features. As mitochondrial dysfunction was the underlying pathomechanism in 47% of the solved individuals, we highlight the sensitivity of the anterior horn cell and peripheral nerve to mitochondrial imbalance as well as the necessity to screen for mitochondrial disorders in individuals presenting predominant lower motor neuron symptoms.
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Affiliation(s)
- Natalie Keller
- Institute of Human Genetics and Institute of Genetics, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Center for Rare Diseases Cologne, University Hospital Cologne, Cologne, Germany
| | - Cem Paketci
- Department of Pediatric Neurology, Dokuz Eylül University, Izmir, Turkey
| | - Janine Altmueller
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Nico Fuhrmann
- Institute of Human Genetics and Institute of Genetics, University of Cologne, Cologne, Germany
| | - Gilbert Wunderlich
- Center for Rare Diseases Cologne, University Hospital Cologne, Cologne, Germany
- Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Bertold Schrank
- Department of Neurology, DKD HELIOS Kliniken, Wiesbaden, Germany
| | - Olcay Unver
- Department of Pediatric Neurology, Marmara University, Istanbul, Turkey
| | - Sanem Yilmaz
- Department of Pediatric Neurology, Ege University, Izmir, Turkey
| | - Reza Boostani
- Department of Neurology, Ghaem Hospital, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ehsan Ghayoor Karimiani
- Molecular and Clinical Sciences Institute, St. George's University of London, Cranmer Terrace, London, UK
| | - Susanne Motameny
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Peter Nürnberg
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Reza Maroofian
- Molecular and Clinical Sciences Institute, St. George's University of London, Cranmer Terrace, London, UK
| | - Uluc Yis
- Department of Pediatric Neurology, Dokuz Eylül University, Izmir, Turkey
| | - Brunhilde Wirth
- Institute of Human Genetics and Institute of Genetics, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Center for Rare Diseases Cologne, University Hospital Cologne, Cologne, Germany
| | - Mert Karakaya
- Institute of Human Genetics and Institute of Genetics, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Center for Rare Diseases Cologne, University Hospital Cologne, Cologne, Germany
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11
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Moutin MJ, Bosc C, Peris L, Andrieux A. Tubulin post-translational modifications control neuronal development and functions. Dev Neurobiol 2020; 81:253-272. [PMID: 33325152 PMCID: PMC8246997 DOI: 10.1002/dneu.22774] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 05/26/2020] [Accepted: 07/14/2020] [Indexed: 12/22/2022]
Abstract
Microtubules (MTs) are an essential component of the neuronal cytoskeleton; they are involved in various aspects of neuron development, maintenance, and functions including polarization, synaptic plasticity, and transport. Neuronal MTs are highly heterogeneous due to the presence of multiple tubulin isotypes and extensive post‐translational modifications (PTMs). These PTMs—most notably detyrosination, acetylation, and polyglutamylation—have emerged as important regulators of the neuronal microtubule cytoskeleton. With this review, we summarize what is currently known about the impact of tubulin PTMs on microtubule dynamics, neuronal differentiation, plasticity, and transport as well as on brain function in normal and pathological conditions, in particular during neuro‐degeneration. The main therapeutic approaches to neuro‐diseases based on the modulation of tubulin PTMs are also summarized. Overall, the review indicates how tubulin PTMs can generate a large number of functionally specialized microtubule sub‐networks, each of which is crucial to specific neuronal features.
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Affiliation(s)
- Marie-Jo Moutin
- Grenoble Institut Neurosciences, University Grenoble Alpes, Inserm, U1216, CEA, CNRS, Grenoble, France
| | - Christophe Bosc
- Grenoble Institut Neurosciences, University Grenoble Alpes, Inserm, U1216, CEA, CNRS, Grenoble, France
| | - Leticia Peris
- Grenoble Institut Neurosciences, University Grenoble Alpes, Inserm, U1216, CEA, CNRS, Grenoble, France
| | - Annie Andrieux
- Grenoble Institut Neurosciences, University Grenoble Alpes, Inserm, U1216, CEA, CNRS, Grenoble, France
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12
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Keller N, Mendoza-Ferreira N, Maroofian R, Chelban V, Khalil Y, Mills PB, Boostani R, Torbati PN, Karimiani EG, Thiele H, Houlden H, Wirth B, Karakaya M. Hereditary polyneuropathy with optic atrophy due to PDXK variant leading to impaired Vitamin B6 metabolism. Neuromuscul Disord 2020; 30:583-589. [DOI: 10.1016/j.nmd.2020.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 01/13/2023]
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13
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Jedličková I, Přistoupilová A, Nosková L, Majer F, Stránecký V, Hartmannová H, Hodaňová K, Trešlová H, Hýblová M, Solár P, Minárik G, Giertlová M, Kmoch S. Spinal muscular atrophy caused by a novel Alu-mediated deletion of exons 2a-5 in SMN1 undetectable with routine genetic testing. Mol Genet Genomic Med 2020; 8:e1238. [PMID: 32337852 PMCID: PMC7336725 DOI: 10.1002/mgg3.1238] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/10/2020] [Accepted: 03/12/2020] [Indexed: 12/26/2022] Open
Abstract
Background Spinal muscular atrophy (SMA) is an inherited neuromuscular disease affecting 1 in 8,000 newborns. The majority of patients carry bi‐allelic variants in the survival of motor neuron 1 gene (SMN1). SMN1 is located in a duplicated region on chromosome 5q13 that contains Alu elements and is predisposed to genomic rearrangements. Due to the genomic complexity of the SMN region and genetic heterogeneity, approximately 50% of SMA patients remain without genetic diagnosis that is a prerequisite for genetic treatments. In this work we describe the diagnostic odyssey of one SMA patient in whom routine diagnostics identified only a maternal heterozygous SMN1Δ(7–8) deletion. Methods We characterized SMN transcripts, assessed SMN protein content in peripheral blood mononuclear cells (PBMC), estimated SMN genes dosage, and mapped genomic rearrangement in the SMN region. Results We identified an Alu‐mediated deletion encompassing exons 2a‐5 of SMN1 on the paternal allele and a complete deletion of SMN1 on the maternal allele as the cause of SMA in this patient. Conclusion Alu‐mediated rearrangements in SMN1 can escape routine diagnostic testing. Parallel analysis of SMN gene dosage, SMN transcripts, and total SMN protein levels in PBMC can identify genomic rearrangements and should be considered in genetically undefined SMA cases.
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Affiliation(s)
- Ivana Jedličková
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Anna Přistoupilová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Lenka Nosková
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Filip Majer
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Viktor Stránecký
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Hana Hartmannová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Kateřina Hodaňová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Helena Trešlová
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | | | - Peter Solár
- Department of Medical Biology, Faculty of Medicine, P.J. Safarik University, Kosice, Slovakia
| | - Gabriel Minárik
- Department of Clinical Genetics, Medirex A.S., Kosice, Slovakia
| | - Mária Giertlová
- Department of Clinical Genetics, Medirex A.S., Kosice, Slovakia
| | - Stanislav Kmoch
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
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14
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The tubulin code and its role in controlling microtubule properties and functions. Nat Rev Mol Cell Biol 2020; 21:307-326. [PMID: 32107477 DOI: 10.1038/s41580-020-0214-3] [Citation(s) in RCA: 379] [Impact Index Per Article: 94.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2020] [Indexed: 02/07/2023]
Abstract
Microtubules are core components of the eukaryotic cytoskeleton with essential roles in cell division, shaping, motility and intracellular transport. Despite their functional heterogeneity, microtubules have a highly conserved structure made from almost identical molecular building blocks: the tubulin proteins. Alternative tubulin isotypes and a variety of post-translational modifications control the properties and functions of the microtubule cytoskeleton, a concept known as the 'tubulin code'. Here we review the current understanding of the molecular components of the tubulin code and how they impact microtubule properties and functions. We discuss how tubulin isotypes and post-translational modifications control microtubule behaviour at the molecular level and how this translates into physiological functions at the cellular and organism levels. We then go on to show how fine-tuning of microtubule function by some tubulin modifications can affect homeostasis and how perturbation of this fine-tuning can lead to a range of dysfunctions, many of which are linked to human disease.
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15
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Bodakuntla S, Schnitzler A, Villablanca C, Gonzalez-Billault C, Bieche I, Janke C, Magiera MM. Tubulin polyglutamylation is a general traffic-control mechanism in hippocampal neurons. J Cell Sci 2020; 133:jcs241802. [PMID: 31932508 DOI: 10.1242/jcs.241802] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 12/23/2019] [Indexed: 08/31/2023] Open
Abstract
Neurons are highly complex cells that heavily rely on intracellular transport to distribute a range of functionally essential cargoes within the cell. Post-translational modifications of tubulin are emerging as mechanisms for regulating microtubule functions, but their impact on neuronal transport is only marginally understood. Here, we have systematically studied the impact of post-translational polyglutamylation on axonal transport. In cultured hippocampal neurons, deletion of a single deglutamylase, CCP1 (also known as AGTPBP1), is sufficient to induce abnormal accumulation of polyglutamylation, i.e. hyperglutamylation. We next investigated how hyperglutamylation affects axonal transport of a range of functionally different neuronal cargoes: mitochondria, lysosomes, LAMP1 endosomes and BDNF vesicles. Strikingly, we found a reduced motility for all these cargoes, suggesting that polyglutamylation could act as a regulator of cargo transport in neurons. This, together with the recent discovery that hyperglutamylation induces neurodegeneration, makes it likely that perturbed neuronal trafficking could be one of the central molecular causes underlying this novel type of degeneration.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Satish Bodakuntla
- Institut Curie, PSL Research University, CNRS UMR3348, F-91405 Orsay, France
- Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, F-91405 Orsay, France
| | - Anne Schnitzler
- Institut Curie, PSL Research University, Department of Genetics, F-75005 Paris, France
| | - Cristopher Villablanca
- Center for Geroscience, Brain Health and Metabolism (GERO), Santiago 7800003, Chile
- Department of Biology, Faculty of Sciences, University of Chile, Santiago 7800003, Chile
| | - Christian Gonzalez-Billault
- Center for Geroscience, Brain Health and Metabolism (GERO), Santiago 7800003, Chile
- Department of Biology, Faculty of Sciences, University of Chile, Santiago 7800003, Chile
| | - Ivan Bieche
- Institut Curie, PSL Research University, Department of Genetics, F-75005 Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, F-75005 Paris, France
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS UMR3348, F-91405 Orsay, France
- Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, F-91405 Orsay, France
| | - Maria M Magiera
- Institut Curie, PSL Research University, CNRS UMR3348, F-91405 Orsay, France
- Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, F-91405 Orsay, France
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