1
|
Appel CD, Bermek O, Dandey VP, Wood M, Viverette E, Williams JG, Bouvette J, Riccio AA, Krahn JM, Borgnia MJ, Williams RS. Sen1 architecture: RNA-DNA hybrid resolution, autoregulation, and insights into SETX inactivation in AOA2. Mol Cell 2023; 83:3692-3706.e5. [PMID: 37832548 PMCID: PMC10629462 DOI: 10.1016/j.molcel.2023.09.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 07/25/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023]
Abstract
The senataxin (SETX, Sen1 in yeasts) RNA-DNA hybrid resolving helicase regulates multiple nuclear transactions, including DNA replication, transcription, and DNA repair, but the molecular basis for Sen1 activities is ill defined. Here, Sen1 cryoelectron microscopy (cryo-EM) reconstructions reveal an elongated inchworm-like architecture. Sen1 is composed of an amino terminal helical repeat Sen1 N-terminal (Sen1N) regulatory domain that is flexibly linked to its C-terminal SF1B helicase motor core (Sen1Hel) via an intrinsically disordered tether. In an autoinhibited state, the Sen1Sen1N domain regulates substrate engagement by promoting occlusion of the RNA substrate-binding cleft. The X-ray structure of an activated Sen1Hel engaging single-stranded RNA and ADP-SO4 shows that the enzyme encircles RNA and implicates a single-nucleotide power stroke in the Sen1 RNA translocation mechanism. Together, our data unveil dynamic protein-protein and protein-RNA interfaces underpinning helicase regulation and inactivation of human SETX activity by RNA-binding-deficient mutants in ataxia with oculomotor apraxia 2 neurodegenerative disease.
Collapse
Affiliation(s)
- C Denise Appel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Oya Bermek
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Venkata P Dandey
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Makayla Wood
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Elizabeth Viverette
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Jason G Williams
- Epigenetics and Stem Cell Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Jonathan Bouvette
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Amanda A Riccio
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Juno M Krahn
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Mario J Borgnia
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - R Scott Williams
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA.
| |
Collapse
|
2
|
Saha S, Yang X, Huang SYN, Agama K, Baechler SA, Sun Y, Zhang H, Saha LK, Su S, Jenkins LM, Wang W, Pommier Y. Resolution of R-loops by topoisomerase III-β (TOP3B) in coordination with the DEAD-box helicase DDX5. Cell Rep 2022; 40:111067. [PMID: 35830799 PMCID: PMC10575568 DOI: 10.1016/j.celrep.2022.111067] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/20/2022] [Accepted: 06/16/2022] [Indexed: 11/16/2022] Open
Abstract
The present study demonstrates how TOP3B is involved in resolving R-loops. We observed elevated R-loops in TOP3B knockout cells (TOP3BKO), which are suppressed by TOP3B transfection. R-loop-inducing agents, the topoisomerase I inhibitor camptothecin, and the splicing inhibitor pladienolide-B also induce higher R-loops in TOP3BKO cells. Camptothecin- and pladienolide-B-induced R-loops are concurrent with the induction of TOP3B cleavage complexes (TOP3Bccs). RNA/DNA hybrid IP-western blotting show that TOP3B is physically associated with R-loops. Biochemical assays using recombinant TOP3B and oligonucleotides mimicking R-loops show that TOP3B cleaves the single-stranded DNA displaced by the R-loop RNA-DNA duplex. IP-mass spectrometry and IP-western experiments reveal that TOP3B interacts with the R-loop helicase DDX5 independently of TDRD3. Finally, we demonstrate that DDX5 and TOP3B are epistatic in resolving R-loops in a pathway parallel with senataxin. We propose a decatenation model for R-loop resolution by TOP3B-DDX5 protecting cells from R-loop-induced damage.
Collapse
Affiliation(s)
- Sourav Saha
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Xi Yang
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Shar-Yin Naomi Huang
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Keli Agama
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Simone Andrea Baechler
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Yilun Sun
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Hongliang Zhang
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Liton Kumar Saha
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Shuaikun Su
- Laboratory of Genetics and Genomics, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Lisa M Jenkins
- Collaborative Protein Technology Resource, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Weidong Wang
- Laboratory of Genetics and Genomics, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Yves Pommier
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
3
|
Beppu S, Ikenaka K, Yabumoto T, Todo K, Hashiguchi A, Takashima H, Mochizuki H. [A case of sporadic amyotrophic lateral sclerosis (ALS) with Senataxin (SETX) gene variant]. Rinsho Shinkeigaku 2022; 62:205-210. [PMID: 35228463 DOI: 10.5692/clinicalneurol.cn-001675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A 67-year-old man presented slowly progressive weakness of the extremities visited our hospital. Nerve conduction study showed axonal neuropathy and needle electromyography showed neurogenic changes with denervation findings in multiple limb muscles. While he was diagnosed as Probable amyotrophic lateral sclerosis (ALS), which is defined by the Awaji criteria for diagnosis of ALS, he did not develop either respiratory muscle paralysis or bulbar palsy, which are characteristic symptoms of sporadic ALS. Genetic testing revealed a novel gene variant in senataxin (SETX), the causative gene of ALS4. We could not make a definite diagnosis of ALS4 because he had no relatives who could perform genetic testing (segregation study). However, we considered the variant can be pathogenic because it was not previously reported and absent in at least 1,000 healthy control individuals, the variant site was highly conserved in mammals, and it may impair the function of senataxin protein (in silico analysis).
Collapse
Affiliation(s)
- Shohei Beppu
- Department of Neurology, Osaka University Graduate School of Medicine
| | - Kensuke Ikenaka
- Department of Neurology, Osaka University Graduate School of Medicine
| | - Taiki Yabumoto
- Department of Neurology, Osaka University Graduate School of Medicine
| | - Kenichi Todo
- Department of Neurology, Osaka University Graduate School of Medicine
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine
| |
Collapse
|
4
|
Perry MD, Evans MJ, Byrd PJ, Taylor MR. Biallelic Mutation of SETX and Additional Likely "In Cis" SETX Sequence Change in Ataxia with Oculomotor Apraxia Type 2. J Pediatr Genet 2021; 10:311-314. [PMID: 34849277 PMCID: PMC8608479 DOI: 10.1055/s-0040-1713909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 05/27/2020] [Indexed: 10/23/2022]
Abstract
Ataxia with oculomotor apraxia type 2 (AOA2) is a slowly progressive, autosomal recessive disease characterized by the triad of ataxia, oculomotor apraxia, and sensorimotor neuropathy. The genetic basis of AOA2 is biallelic mutation of the SETX gene, resulting in reduced or absent senataxin, a DNA/RNA repair protein essential for genomic stability. In this case report, we described a case of AOA2 with two clear pathogenic SETX mutations, one of which is novel. We then discussed two further likely "in cis" SETX sequence changes (previously reported in the literature as pathogenic), and presented the case that they are likely benign polymorphisms.
Collapse
Affiliation(s)
- Michael D. Perry
- Department of Medical Education, St George’s Hospital Medical School, University of London, London, United Kingdom
| | - Martin J. Evans
- Department of Medical Education, St George’s Hospital Medical School, University of London, London, United Kingdom
- Department of Postgraduate Medical Education, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Philip J. Byrd
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Malcolm R. Taylor
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom
| |
Collapse
|
5
|
Richard P, Feng S, Tsai YL, Li W, Rinchetti P, Muhith U, Irizarry-Cole J, Stolz K, Sanz LA, Hartono S, Hoque M, Tadesse S, Seitz H, Lotti F, Hirano M, Chédin F, Tian B, Manley JL. SETX ( senataxin), the helicase mutated in AOA2 and ALS4, functions in autophagy regulation. Autophagy 2020; 17:1889-1906. [PMID: 32686621 DOI: 10.1080/15548627.2020.1796292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SETX (senataxin) is an RNA/DNA helicase that has been implicated in transcriptional regulation and the DNA damage response through resolution of R-loop structures. Mutations in SETX result in either of two distinct neurodegenerative disorders. SETX dominant mutations result in a juvenile form of amyotrophic lateral sclerosis (ALS) called ALS4, whereas recessive mutations are responsible for ataxia called ataxia with oculomotor apraxia type 2 (AOA2). How mutations in the same protein can lead to different phenotypes is still unclear. To elucidate AOA2 disease mechanisms, we first examined gene expression changes following SETX depletion. We observed the effects on both transcription and RNA processing, but surprisingly observed decreased R-loop accumulation in SETX-depleted cells. Importantly, we discovered a strong connection between SETX and the macroautophagy/autophagy pathway, reflecting a direct effect on transcription of autophagy genes. We show that SETX depletion inhibits the progression of autophagy, leading to an accumulation of ubiquitinated proteins, decreased ability to clear protein aggregates, as well as mitochondrial defects. Analysis of AOA2 patient fibroblasts also revealed a perturbation of the autophagy pathway. Our work has thus identified a novel function for SETX in the regulation of autophagy, whose modulation may have a therapeutic impact for AOA2.Abbreviations: 3'READS: 3' region extraction and deep sequencing; ACTB: actin beta; ALS4: amyotrophic lateral sclerosis type 4; AOA2: ataxia with oculomotor apraxia type 2; APA: alternative polyadenylation; AS: alternative splicing; ATG7: autophagy-related 7; ATP6V0D2: ATPase H+ transporting V0 subunit D2; BAF: bafilomycin A1; BECN1: beclin 1; ChIP: chromatin IP; Chloro: chloroquine; CPT: camptothecin; DDR: DNA damage response; DNMT1: DNA methyltransferase 1; DRIP: DNA/RNA IP; DSBs: double strand breaks; EBs: embryoid bodies; FTD: frontotemporal dementia; GABARAP: GABA type A receptor-associated protein; GO: gene ontology; HR: homologous recombination; HTT: huntingtin; IF: immunofluorescence; IP: immunoprecipitation; iPSCs: induced pluripotent stem cells; KD: knockdown; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MN: motor neuron; MTORC1: mechanistic target of rapamycin kinase complex 1; PASS: PolyA Site Supporting; PFA: paraformaldehyde; RNAPII: RNA polymerase II; SCA: spinocerebellar ataxia; SETX: senataxin; SMA: spinal muscular atrophy; SMN1: survival of motor neuron 1, telomeric; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; TSS: transcription start site; TTS: transcription termination site; ULK1: unc-51 like autophagy activating kinase 1; WB: western blot; WIPI2: WD repeat domain, phosphoinositide interacting 2; XRN2: 5'-3' exoribonuclease 2.
Collapse
Affiliation(s)
- Patricia Richard
- Department of Biological Sciences, Columbia University, New York, NY, USA.,Stellate Therapeutics, JLABS @ NYC, New York, NY, USA
| | | | - Yueh-Lin Tsai
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Wencheng Li
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Paola Rinchetti
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA.,Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
| | - Ubayed Muhith
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Juan Irizarry-Cole
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Katharine Stolz
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Lionel A Sanz
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Stella Hartono
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Mainul Hoque
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Saba Tadesse
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Hervé Seitz
- Institut de Génétique Humaine, UMR 9002 CNRS and Université de Montpellier, Montpellier, France
| | - Francesco Lotti
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Frédéric Chédin
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Bin Tian
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA.,Gene Expression and Regulation Program, and Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA, USA
| | - James L Manley
- Department of Biological Sciences, Columbia University, New York, NY, USA
| |
Collapse
|
6
|
Kitao R, Honma Y, Hashiguchi A, Mizoguchi K, Takashima H, Komori T. [A case of motor and sensory polyneuropathy and respiratory failure with novel heterozygous mutation of the senataxin gene]. Rinsho Shinkeigaku 2020; 60:466-472. [PMID: 32536663 DOI: 10.5692/clinicalneurol.60.cn-001415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The patient was a 29-year-old male. He took his first steps at two-and-a-half years old, but his physical strength deteriorated and he became non-ambulatory at 12 years old. He had respiratory failure at the age of 20, and finally underwent tracheostomy with invasive positive-pressure ventilation (TPPV). He showed distal dominant muscle weakness and atrophy, including the face. Spinal scoliosis was recognized. He had peripheral predominance of sensory disorders. Nerve conduction studies showed a decrease of compound muscle action potential and a reduction of motor nerve conduction velocity. Sensory nerve action potential was not evoked. In genetic analysis, c.23 C> T (p. T8M) heterozygous mutation was found in the senataxin gene (SETX). Although SETX is a causative gene of familial amyotrophic lateral sclerosis type 4 (ALS4), this case suggests that SETX mutation can also cause motor and sensory polyneuropathy.
Collapse
Affiliation(s)
- Ruriko Kitao
- Department of Neurology, National Hospital Organization Hakone Hospital
| | - Yutaka Honma
- Department of Neurology, National Hospital Organization Shizuoka Fuji Hospital (Present address: Department of Neurology, National Hospital Organization Shizuoka Medical Center)
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Kouichi Mizoguchi
- Department of Neurology, National Hospital Organization Shizuoka Fuji Hospital (Present address: Department of Neurology, National Hospital Organization Shizuoka Medical Center)
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Tetsuo Komori
- Department of Neurology, National Hospital Organization Hakone Hospital
| |
Collapse
|
7
|
Paucar M, Taylor AMR, Hadjivassiliou M, Fogel BL, Svenningsson P. Progressive Ataxia with Elevated Alpha-Fetoprotein: Diagnostic Issues and Review of the Literature. Tremor Other Hyperkinet Mov (N Y) 2019; 9:tre-09-708. [PMID: 31656689 PMCID: PMC6790008 DOI: 10.7916/tohm.v0.708] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/13/2019] [Indexed: 12/23/2022]
Abstract
Background Ataxias represent a challenging group of disorders due to significant clinical overlap. Here, we present a patient with early-onset progressive ataxia, polyneuropathy and discuss how elevation of alpha fetoprotein (AFP) narrows the differential diagnosis. Case report Ataxia, polyneuropathy, and mild elevation of AFP are features compatible with ataxia with oculomotor apraxia type 2 (AOA2) but also with ataxia with oculomotor apraxia type 4 (AOA4). A genetic analysis demonstrated biallelic mutations in senataxin (SETX), confirming the diagnosis of AOA2. Discussion Mild elevation of AFP is found in patients with AOA2 and AOA4, and higher levels are commonly seen in ataxia-telangiectasia. AFP is a useful diagnostic tool but not a biomarker for disease progression in AOA2.
Collapse
Affiliation(s)
- Martin Paucar
- Department of Neurology, Karolinska University Hospital, Stockholm, SE.,Department of Clinical Neuroscience, Karolinska Institute, Stockholm, SE
| | - Alexander M R Taylor
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | | | - Brent L Fogel
- Department of Neurology, UCLA Program in Neurogenetics, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA
| | - Per Svenningsson
- Department of Neurology, Karolinska University Hospital, Stockholm, SE.,Department of Clinical Neuroscience, Karolinska Institute, Stockholm, SE
| |
Collapse
|
8
|
Algahtani H, Shirah B, Algahtani R, Naseer MI, Al-Qahtani MH, Abdulkareem AA. Ataxia with ocular apraxia type 2 not responding to 4-aminopyridine: A rare mutation in the SETX gene in a Saudi patient. Intractable Rare Dis Res 2018; 7:275-279. [PMID: 30560021 PMCID: PMC6290838 DOI: 10.5582/irdr.2018.01107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Ataxia with ocular apraxia type 2 is an autosomal recessive disorder caused by a mutation in the senataxin (SETX) gene. The disease is characterized by early onset cerebellar ataxia, cerebellar atrophy, axonal sensorimotor neuropathy, oculomotor apraxia, and increased levels of α-fetoprotein. Reported here is a rare homozygous frameshift deletion c.5308_5311del, p.(Glu1770Ilefs*15) in the SETX gene in a Saudi family. Ataxia with ocular apraxia type 2 was diagnosed based on the patient's history, an examination, and genetic testing. Genetic testing remains the only definitive method with which to identify the gene responsible. This is the third case report of this rare mutation in the literature. Ataxia with ocular apraxia type 2 continues to be a challenging disease to manage with no therapeutic options available to date. In the current case, the medication 4-aminopyridine was inefficacious in improving walking or balance. Further research is needed to identify potential treatments for this challenging condition.
Collapse
Affiliation(s)
- Hussein Algahtani
- King Abdulaziz Medical City, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
- Address correspondence to:Dr. Hussein Algahtani, King Abdulaziz Medical City, King Saud bin Abdulaziz University for Health Sciences, Contact No.: 00966556633130. P.O. Box: 12723, Jeddah, Saudi Arabia 21483. E-mail:
| | - Bader Shirah
- King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Raghad Algahtani
- King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohammad H. Al-Qahtani
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia
| | | |
Collapse
|
9
|
Tariq H, Imran R, Naz S. A Novel Homozygous Variant of SETX Causes Ataxia with Oculomotor Apraxia Type 2. J Clin Neurol 2018; 14:498-504. [PMID: 30198223 PMCID: PMC6172491 DOI: 10.3988/jcn.2018.14.4.498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 01/21/2023] Open
Abstract
Background and Purpose Autosomal recessive cerebellar ataxias constitute a highly heterogeneous group of neurodegenerative disorders. This study was carried out to determine the clinical and genetic causes of ataxia in two families from Pakistan. Methods Detailed clinical investigations were carried out on probands in two consanguineous families. Magnetic resonance imaging was performed. Exome sequencing data were examined for likely pathogenic variants. Candidate variants were checked for cosegregation with the phenotype using Sanger sequencing. Public databases including ExAC, GnomAD, dbSNP, and the 1,000 Genome Project as well as ethnically matched controls were checked to determine the frequencies of the alleles. Conservation of missense variants was ensured by aligning orthologous protein sequences from diverse vertebrate species. Results Reverse phenotyping identified spinocerebellar ataxia, autosomal recessive 1 [OMIM 606002, also referred to as ataxia oculomotor apraxia type 2 (AOA2)] and ataxia telangiectasia (OMIM 208900) in the two families. A novel homozygous missense mutation c.202 C>T (p.Arg68Cys) was identified within senataxin, SETX in the DNA of both patients in one of the families with AOA2. The patients in the second family were homozygous for a known variant in ataxia-telangiectasia mutated (ATM) gene: c.7327 C>T (p.Arg2443Ter). Both variants were absent from 100 ethnically matched control chromosomes and were either absent or present at very low frequencies in the public databases. Conclusions This report extends the allelic heterogeneity of SETX mutations causing AOA2 and also presents an asymptomatic patient with a pathogenic ATM variant.
Collapse
Affiliation(s)
- Huma Tariq
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Rashid Imran
- Punjab Institute of Neurosciences, Lahore General Hospital, Lahore, Pakistan
| | - Sadaf Naz
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan.
| |
Collapse
|
10
|
Grunseich C, Wang IX, Watts JA, Burdick JT, Guber RD, Zhu Z, Bruzel A, Lanman T, Chen K, Schindler AB, Edwards N, Ray-Chaudhury A, Yao J, Lehky T, Piszczek G, Crain B, Fischbeck KH, Cheung VG. Senataxin Mutation Reveals How R-Loops Promote Transcription by Blocking DNA Methylation at Gene Promoters. Mol Cell 2018; 69:426-437.e7. [PMID: 29395064 PMCID: PMC5815878 DOI: 10.1016/j.molcel.2017.12.030] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 12/11/2017] [Accepted: 12/28/2017] [Indexed: 12/15/2022]
Abstract
R-loops are three-stranded nucleic acid structures found abundantly and yet often viewed as by-products of transcription. Studying cells from patients with a motor neuron disease (amyotrophic lateral sclerosis 4 [ALS4]) caused by a mutation in senataxin, we uncovered how R-loops promote transcription. In ALS4 patients, the senataxin mutation depletes R-loops with a consequent effect on gene expression. With fewer R-loops in ALS4 cells, the expression of BAMBI, a negative regulator of transforming growth factor β (TGF-β), is reduced; that then leads to the activation of the TGF-β pathway. We uncovered that genome-wide R-loops influence promoter methylation of over 1,200 human genes. DNA methyl-transferase 1 favors binding to double-stranded DNA over R-loops. Thus, in forming R-loops, nascent RNA blocks DNA methylation and promotes further transcription. Hence, our results show that nucleic acid structures, in addition to sequences, influence the binding and activity of regulatory proteins.
Collapse
Affiliation(s)
- Christopher Grunseich
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Isabel X Wang
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Jason A Watts
- Department of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Joshua T Burdick
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Robert D Guber
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Zhengwei Zhu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Alan Bruzel
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Tyler Lanman
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Kelian Chen
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Alice B Schindler
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Nancy Edwards
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Abhik Ray-Chaudhury
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Jianhua Yao
- Department of Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD, USA
| | - Tanya Lehky
- Electromyography Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Grzegorz Piszczek
- Biophysics Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Barbara Crain
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kenneth H Fischbeck
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA.
| | - Vivian G Cheung
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA; Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
11
|
Choudhury SD, Vs A, Mushtaq Z, Kumar V. Altered translational repression of an RNA-binding protein, Elav by AOA2-causative Senataxin mutation. Synapse 2017; 71. [PMID: 28245518 DOI: 10.1002/syn.21969] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 02/20/2017] [Accepted: 02/22/2017] [Indexed: 11/09/2022]
Abstract
Mutations in Senataxin (SETX) gene causes two types of neurological disorders, Amyotrophic Lateral Sclerosis (ALS4) and Ataxia with Oculomotor Apraxia type 2 (AOA2). Recent studies in cultured cells suggest that SETX plays a crucial role at the interface of transcription and the DNA damage response. Whether SETX can alter translational of specific RNA is not known. In this study, we report that expressing AOA2-causative truncated form of human SETX in Drosophila neurons alters the development of neuromuscular junction (NMJ) synapses. Interestingly, we found that expressing this truncated form of SETX in Drosophila muscles resulted in an alteration of translational repression of an RNA-binding protein, Embryonic Lethal Abnormal Vision (Elav). Elav is transcribed in all tissues but remains translationally repressed except in neurons. Thus, our data suggest that an altered repression profile of RNA by SETX mutants could be one of the mechanisms underlying ALS4 or AOA2 pathogenesis.
Collapse
Affiliation(s)
- Saumitra Dey Choudhury
- Department of Biological Sciences, Laboratory of Neurogenetics, Indian Institute of Science Education and Research (IISER) Bhopal, Bhouri, Bhopal, Madhya Pradesh, India, 462 066
| | - Ancy Vs
- Department of Biological Sciences, Laboratory of Neurogenetics, Indian Institute of Science Education and Research (IISER) Bhopal, Bhouri, Bhopal, Madhya Pradesh, India, 462 066
| | - Zeeshan Mushtaq
- Department of Biological Sciences, Laboratory of Neurogenetics, Indian Institute of Science Education and Research (IISER) Bhopal, Bhouri, Bhopal, Madhya Pradesh, India, 462 066
| | - Vimlesh Kumar
- Department of Biological Sciences, Laboratory of Neurogenetics, Indian Institute of Science Education and Research (IISER) Bhopal, Bhouri, Bhopal, Madhya Pradesh, India, 462 066
| |
Collapse
|
12
|
Yeo AJ, Becherel OJ, Luff JE, Graham ME, Richard D, Lavin MF. Senataxin controls meiotic silencing through ATR activation and chromatin remodeling. Cell Discov 2015; 1:15025. [PMID: 27462424 DOI: 10.1038/celldisc.2015.25] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/17/2015] [Indexed: 12/13/2022] Open
Abstract
Senataxin, defective in ataxia oculomotor apraxia type 2, protects the genome by facilitating the resolution of RNA–DNA hybrids (R-loops) and other aspects of RNA processing. Disruption of this gene in mice causes failure of meiotic recombination and defective meiotic sex chromosome inactivation, leading to male infertility. Here we provide evidence that the disruption of Setx leads to reduced SUMOylation and disruption of protein localization across the XY body during meiosis. We demonstrate that senataxin and other DNA damage repair proteins, including ataxia telangiectasia and Rad3-related protein-interacting partner, are SUMOylated, and a marked downregulation of both ataxia telangiectasia and Rad3-related protein-interacting partner and TopBP1 leading to defective activation and signaling through ataxia telangiectasia and Rad3-related protein occurs in the absence of senataxin. Furthermore, chromodomain helicase DNA-binding protein 4, a component of the nucleosome remodeling and deacetylase chromatin remodeler that interacts with both ataxia telangiectasia and Rad3-related protein and senataxin was not recruited efficiently to the XY body, triggering altered histone acetylation and chromatin conformation in Setx−/− pachytene-staged spermatocytes. These results demonstrate that senataxin has a critical role in ataxia telangiectasia and Rad3-related protein- and chromodomain helicase DNA-binding protein 4-mediated transcriptional silencing and chromatin remodeling during meiosis providing greater insight into its critical role in gene regulation to protect against neurodegeneration.
Collapse
|
13
|
Brugger F, Schüpbach M, Koenig M, Müri R, Bohlhalter S, Kaelin-Lang A, Kamm CP, Kägi G. The Clinical Spectrum of Ataxia with Oculomotor Apraxia Type 2. Mov Disord Clin Pract 2014; 1:106-109. [PMID: 30363866 DOI: 10.1002/mdc3.12021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/10/2014] [Accepted: 03/12/2014] [Indexed: 11/07/2022] Open
Abstract
Ataxia with oculomotor apraxia type 2 (AOA2) is an inherited disorder caused by mutations within both alleles of the senataxin gene. First symptoms are usually recognized before the age of 30. Unlike several other autosomal recessive cerebellar ataxia syndromes, levels of alpha-fetoprotein are nearly always elevated in AOA2 and thus narrowing down the differential diagnosis list. We present 3 video cases illustrating and expanding the clinical spectrum of AOA2, with 1 case bearing a novel mutation with cervical dystonia as the first symptom, the absence of neuropathy, and a disease onset beyond the age of 40. Furthermore, all patients were assessed by oculographic analysis, which revealed distinct patterns of oculomotor abnormalities. The clinical spectrum of AOA2 might be even broader than previously described in larger series. Oculography might be a useful tool to detect subclinical oculomotor apraxia in this disorder.
Collapse
Affiliation(s)
- Florian Brugger
- Movement Disorders Center of Eastern Switzerland Department of Neurology Kantonsspital St.Gallen St.Gallen Switzerland
| | - Michael Schüpbach
- Movement Disorders Center Department of Neurology University Hospital Berne University of Berne Berne Switzerland
| | - Michel Koenig
- Laboratoire de Diagnostic Génétique Nouvel Hôpital Civil Strasbourg France
- Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS/Université de Strasbourg/INSERM Illkirch France
| | - René Müri
- Perception and Eye Movement Laboratory Departments of Neurology and Clinical Research Inselspital, University Hospital Berne Berne Switzerland
| | - Stephan Bohlhalter
- Perception and Eye Movement Laboratory Departments of Neurology and Clinical Research Inselspital, University Hospital Berne Berne Switzerland
- Neurology and Neurorehabilitation Center Department of Internal Medicine Luzerner Kantonsspital Lucerne Switzerland
| | - Alain Kaelin-Lang
- Movement Disorders Center Department of Neurology University Hospital Berne University of Berne Berne Switzerland
| | - Christian P Kamm
- Perception and Eye Movement Laboratory Departments of Neurology and Clinical Research Inselspital, University Hospital Berne Berne Switzerland
| | - Georg Kägi
- Movement Disorders Center of Eastern Switzerland Department of Neurology Kantonsspital St.Gallen St.Gallen Switzerland
| |
Collapse
|
14
|
Richard P, Manley JL. SETX sumoylation: A link between DNA damage and RNA surveillance disrupted in AOA2. Rare Dis 2014; 2:e27744. [PMID: 25054092 PMCID: PMC4091563 DOI: 10.4161/rdis.27744] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 12/18/2013] [Accepted: 01/06/2014] [Indexed: 01/09/2023] Open
Abstract
Senataxin (SETX) is a putative RNA:DNA helicase that is mutated in two distinct juvenile neurological disorders, AOA2 and ALS4. SETX is involved in the response to oxidative stress and is suggested to resolve R loops formed at transcription termination sites or at sites of collisions between the transcription and replication machineries. R loops are hybrids between RNA and DNA that are believed to lead to DNA damage and genomic instability. We discovered that Rrp45, a core component of the exosome, is a SETX-interacting protein and that the interaction depends on modification of SETX by sumoylation. Importantly, we showed that AOA2 but not ALS4 mutations prevented both SETX sumoylation and the Rrp45 interaction. We also found that upon replication stress induction, SETX and Rrp45 co-localize in nuclear foci that constitute sites of R-loop formation generated by transcription and replication machinery collisions. We suggest that SETX links transcription, DNA damage and RNA surveillance, and discuss here how this link can be relevant to AOA2 disease.
Collapse
Affiliation(s)
- Patricia Richard
- Department of Biological Sciences; Columbia University; New York, NY USA
| | - James L Manley
- Department of Biological Sciences; Columbia University; New York, NY USA
| |
Collapse
|
15
|
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that is usually fatal within 2-5years. Unfortunately, the only treatment currently available is riluzole, which has a limited efficacy. As a redress, there is an expanding literature focusing on other potential treatments. One such potential treatment option utilizes the vascular endothelial growth factor (VEGF) family, which includes factors that are primarily associated with angiogenesis but are now increasingly recognized to have neurotrophic effects. Reduced expression of a member of this family, VEGF-A, in mice results in neurodegeneration similar to that of ALS, while treatment of animal models of ALS with either VEGF-A gene therapy or VEGF-A protein has yielded positive therapeutic outcomes. These basic research findings raise the potential for a VEGF therapy to be translated to the clinic for the treatment of ALS. This review covers the VEGF family, its receptors and neurotrophic effects as well as VEGF therapy in animal models of ALS and advances towards clinical trials.
Collapse
Affiliation(s)
- Orion P Keifer
- Department of Neurosurgery, Emory University, 101 Woodruff Circle, Atlanta, GA 30322, United States
| | - Deirdre M O'Connor
- Department of Neurosurgery, Emory University, 101 Woodruff Circle, Atlanta, GA 30322, United States
| | - Nicholas M Boulis
- Department of Neurosurgery, Emory University, 101 Woodruff Circle, Atlanta, GA 30322, United States.
| |
Collapse
|
16
|
Lavin MF, Yeo AJ, Becherel OJ. Senataxin protects the genome: Implications for neurodegeneration and other abnormalities. Rare Dis 2013; 1:e25230. [PMID: 25003001 PMCID: PMC3927485 DOI: 10.4161/rdis.25230] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 05/31/2013] [Indexed: 11/29/2022] Open
Abstract
Ataxia oculomotor apraxia type 2 (AOA2) is a rare autosomal recessive disorder characterized by cerebellar atrophy, peripheral neuropathy, loss of Purkinje cells and elevated α-fetoprotein. AOA2 is caused by mutations in the SETX gene that codes for the high molecular weight protein senataxin. Mutations in this gene also cause dominant neurodegenerative disorders. Similar to that observed for other autosomal recessive ataxias, this protein protects the integrity of the genome against oxidative and other forms of DNA damage to reduce the risk of neurodegeneration. Senataxin functions in transcription termination and RNA splicing and it has been shown to resolve RNA/DNA hybrids (R-loops) that arise at transcription pause sites or when transcription is blocked. Recent data suggest that this protein functions at the interface between transcription and DNA replication to minimise the risk of collision and maintain genome stability. Our recent data using SETX gene-disrupted mice revealed that male mice were defective in spermatogenesis and were infertile. DNA double strand-breaks persisted throughout meiosis and crossing-over failed in SETX mutant mice. These changes can be explained by the accumulation of R-loops, which interfere with Holiday junctions and crossing-over. We also showed that senataxin was localized to the XY body in pachytene cells and was involved in transcriptional silencing of these chromosomes. While the defect in meiotic recombination was striking in these animals, there was no evidence of neurodegeneration as observed in AOA2 patients. We discuss here potentially different roles for senataxin in proliferating and post-mitotic cells.
Collapse
Affiliation(s)
- Martin F Lavin
- Queensland Institute of Medical Research; Radiation Biology and Oncology; Brisbane, QLD, Australia ; University of Queensland Centre for Clinical Research; Herston, QLD, Australia
| | - Abrey J Yeo
- Queensland Institute of Medical Research; Radiation Biology and Oncology; Brisbane, QLD, Australia ; School of Medicine; University of Queensland; Herston, QLD, Australia
| | - Olivier J Becherel
- Queensland Institute of Medical Research; Radiation Biology and Oncology; Brisbane, QLD, Australia ; School of Chemistry & Molecular Biosciences; University of Queensland; St. Lucia, QLD, Australia
| |
Collapse
|