Abstract
Ataxia with oculomotor apraxia (AOA) type 2 (AOA2 MIM 606002) is a recessive subtype of AOA characterized by cerebellar atrophy, oculomotor apraxia, early loss of reflexes, and peripheral neuropathy. Various mutations either in homozygous or compound heterozygous condition were so far identified in the associated gene SETX (MIM 608465). SETX encodes a large protein called senataxin with a DNA-RNA helicase domain and a putative N-terminus protein interaction domain. Here, we report the identification of two novel homozygous mutations in SETX gene, c.340_342delCTT (p.L114Del) and c.1669C > T (p.R557X), in two AOA2 families. The characterization of the mutant lymphoblastoid cell lines for sensitivity to oxidative DNA-damaging agents indicates that the p.L114Del deletion confers an increased sensitivity to H2O2, camptothecin, and mitomycin C, previously found to induce death in lymphoblasts harbouring other SETX mutations; the cells carrying the nonsense mutation display instead values within the normal range. Further analysis of a neuronal cell model SKNBE, transfected with the mutant senataxin proteins, reveals increased sensitivity also to staurosporine and excitotoxicity associated with the p.L114Del mutant only. We also demonstrate that the sensitizing effect of p.L114Del on apoptosis can be reversed by senataxin silencing. The ability of a single amino acid deletion to sensitize cells to death by different agents, compared to the lack of effect of a whole protein deletion, seems to exclude a protective role played by the native protein while suggesting that a specific mutation confers to the protein the ability to enhance the toxic effect of various cell damaging agents.
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References
Fogel BL, Perlman S (2007) Clinical features and molecular genetics of autosomal recessive cerebellar ataxias. Lancet Neurol 6(3):245–257
Date H, Onodera O, Tanaka H, Iwabuchi K, Uekawa K, Igarashi S, Koike R, Hiroi T, Yuasa T, Awaya Y, Sakai T, Takahashi T, Nagatomo H, Sekijima Y, Kawachi I, Takiyama Y, Nishizawa M, Fukuhara N, Saito K, Sugano S, Tsuji S (2001) Early-onset ataxia with ocular motor apraxia and hypoalbuminemia is caused by mutations in a new HIT superfamily gene. Nat Genet 29(2):184–188
Moreira MC, Barbot C, Tachi N, Kozuka N, Uchida E, Gibson T, Mendonça P, Costa M, Barros J, Yanagisawa T, Watanabe M, Ikeda Y, Aoki M, Nagata T, Coutinho P, Sequeiros J, Koenig M (2001) The gene mutated in ataxia-ocular apraxia 1 encodes the new HIT/Zn-finger protein aprataxin. Nat Genet 29(2):189–193
Moreira MC, Klur S, Watanabe M, Németh AH, Le Ber I, Moniz JC, Tranchant C, Aubourg P, Tazir M, Schöls L, Pandolfo M, Schulz JB, Pouget J, Calvas P, Shizuka-Ikeda M, Shoji M, Tanaka M, Izatt L, Shaw CE, M’Zahem A, Dunne E, Bomont P, Benhassine T, Bouslam N, Stevanin G, Brice A, Guimarães J, Mendonça P, Barbot C, Coutinho P, Sequeiros J, Dürr A, Warter JM, Koenig M (2004) Senataxin, the ortholog of a yeast RNA helicase, is mutant in ataxia-ocular apraxia 2. Nat Genet 36(3):225–227
Gueven N, Becherel OJ, Kijas AW, Chen P, Howe O, Rudolph JH, Gatti R, Date H, Onodera O, Taucher-Scholz G, Lavin MF (2004) Aprataxin, a novel protein that protects against genotoxic stress. Hum Mol Genet 13(10):1081–1093
Gueven N, Chen P, Nakamura J, Becherel OJ, Kijas AW, Grattan-Smith P, Lavin MF (2007) A subgroup of spinocerebellar ataxias defective in DNA damage responses. Neuroscience 145(4):1418–1425
Le Ber I, Brice A, Dürr A (2005) New autosomal recessive cerebellar ataxias with oculomotor apraxia. Curr Neurol Neurosci Rep 5(5):411–417
Criscuolo C, Chessa L, Di Giandomenico S, Mancini P, Saccà F, Grieco GS, Piane M, Barbieri F, De Michele G, Banfi S, Pierelli F, Rizzuto N, Santorelli FM, Gallosti L, Filla A, Casali C (2006) Ataxia with oculomotor apraxia type 2: a clinical, pathologic, and genetic study. Neurology 66:1207–1210
Duquette A, Roddier K, McNabb-Baltar J, Gosselin I, St-Denis A, Dicaire MJ, Loisel L, Labuda D, Marchand L, Mathieu J, Bouchard JP, Brais B (2005) Mutations in senataxin responsible for Quebec cluster of ataxia with neuropathy. Ann Neurol 57(3):408–414
Asaka T, Yokoji H, Ito J, Yamaguchi K, Matsushima A (2006) Autosomal recessive ataxia with peripheral neuropathy and elevated AFP: novel mutations in SETX. Neurology 66(10):1580–1581
Fogel BL, Perlman S (2006) Novel mutations in the senataxin DNA/RNA helicase domain in ataxia with oculomotor apraxia 2. Neurology 67(11):2083–2084
Lynch DR, Braastad CD, Nagan N (2007) Ovarian failure in ataxia with oculomotor apraxia type 2. Am J Med Genet 143A(15):1775–1777
Suraweera A, Becherel OJ, Chen P, Rundle N, Woods R, Nakamura J, Gatei M, Criscuolo C, Filla A, Chessa L, Fusser M, Epe B, Gueven N, Lavin MF (2007) Senataxin, defective in ataxia oculomotor apraxia type 2, is involved in the defense against oxidative DNA damage. J Cell Biol 177(6):969–979
Nicolaou P, Georghiou A, Votsi C, Middleton LT, Zamba-Papanicolaou E, Christodoulou K (2008) A novel c.5308_5311delGAGA mutation in Senataxin in a Cypriot family with an autosomal recessive cerebellar ataxia. BMC Med Genet 14:9–28
Arning L, Schöls L, Cin H, Souquet M, Epplen JT, Timmann D (2008) Identification and characterisation of a large Senataxin (SETX) gene duplication in ataxia with ocular apraxia type 2 (AOA2). Neurogenetics 9(4):295–299
Anheim M, Fleury MC, Franques J, Moreira MC, Delaunoy JP, Stoppa-Lyonnet D, Koenig M, Tranchant C (2008) Clinical and molecular findings of ataxia with oculomotor apraxia type 2 in 4 families. Arch Neurol 65(7):958–962
Tazir M, Ali-Pacha L, M’zahem A, Delaunoy JP, Fritsch M, Nouioua S, Benhassine T, Assami S, Grid D, Vallat JM, Hamri A, Koenig M (2009) Ataxia with oculomotor apraxia type 2: a clinical and genetic study of 19 patients. J Neurol Sci 278(1–2):77–81
Bassuk AG, Chen YZ, Batish SD, Nagan N, Opal P, Chance PF, Bennett CL (2007) In cis autosomal dominant mutation of Senataxin associated with tremor/ataxia syndrome. Neurogenetics 8(1):45–49
Chen YZ, Bennett CL, Huynh HM, Blair IP, Puls I, Irobi J, Dierick I, Abel A, Kennerson ML, Rabin BA, Nicholson GA, Auer-Grumbach M, Wagner K, De Jonghe P, Griffin JW, Fischbeck KH, Timmerman V, Cornblath DR, Chance PF (2004) DNA/RNA helicase gene mutations in a form of juvenile amyotrophic lateral sclerosis (ALS4). Am J Hum Genet 74(6):1128–1135
Schöls L, Arning L, Schüle R, Epplen JT, Timmann D (2008) “Pseudodominant inheritance” of ataxia with ocular apraxia type 2 (AOA2). J Neurol 255(4):495–501
Chen YZ, Hashemi SH, Anderson SK, Huang Y, Moreira MC, Lynch DR, Glass IA, Chance PF, Bennett CL (2006) Senataxin, the yeast Sen1p orthologue: characterization of a unique protein in which recessive mutations cause ataxia and dominant mutations cause motor neuron disease. Neurobiol Dis 23(1):97–108
Nahas SA, Duquette A, Roddier K, Gatti RA, Brais B (2007) Ataxia-oculomotor apraxia 2 patients show no increased sensitivity to ionizing radiation. Neuromuscul Disord 17(11–12):968–969
Panzeri C, De Palma C, Martinuzzi A, Daga A, De Polo G, Bresolin N, Miller CC, Tudor EL, Clementi E, Bassi MT (2006) The first ALS2 missense mutation associated with JPLS reveals new aspects of alsin biological function. Brain 129(7):1710–1719
Hardingham GE, Bading H (2003) The yin and yang of NMDA receptor signalling. Trends Neurosci 26(2):81–89
McKinnon PJ (2004) ATM and ataxia telangectasia. EMBO Rep 5(8):772–776
Lee JH, Paull TT (2005) ATM activation by DNA double-strand breaks through the Mre11-Rad50-Nbs1 complex. Science 308(5721):551–554
Mosesso P, Piane M, Palitti F, Pepe G, Penna S, Chessa L (2005) The novel human gene aprataxin is directly involved in DNA single-strand-break repair. Cell Mol Life Sci 62(4):485–491
Interthal H, Pouliot JJ, Champoux JJ (2001) The tyrosyl-DNA phosphodiesterase Tdp1 is a member of the phospholipase D superfamily. Proc Natl Acad Sci 98(21):12009–12014
Rass U, Ahel I, West SC (2007) Defective DNA repair and neurodegenerative disease. Cell 130(6):991–1004
Ahel I, Rass U, El-Khamisy SF, Katyal S, Clements PM, McKinnon PJ, Caldecott KW, West SC (2006) The neurodegenerative disease protein aprataxin resolves abortive DNA ligation intermediates. Nature 443:713–716
Acknowledgements
The authors wish to thank the patients and their family for participation to the study. The work was supported by the Italian ministry of Health funds grant # RC2008, RC2009, RF2007 n. 66, and PS-NEURO ex art.56/05/7 (MTB, EC, MGD, NB), by the CARIPLO Foundation, P #.2007.5156 (EC, MTB) and by the Istituto Superiore di Sanita’ (MTB, SB, NB). The experiments herein reported comply with the current Italian laws.
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Airoldi, G., Guidarelli, A., Cantoni, O. et al. Characterization of two novel SETX mutations in AOA2 patients reveals aspects of the pathophysiological role of senataxin. Neurogenetics 11, 91–100 (2010). https://doi.org/10.1007/s10048-009-0206-0
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DOI: https://doi.org/10.1007/s10048-009-0206-0