Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Subscribe

Logo for

J. Biol. Chem. 280 (22): 20927-20931

© 2005 by The American Society for Biochemistry and Molecular Biology, Inc.

Disease-associated Mutations Inactivate AMP-Lysine Hydrolase Activity of Aprataxin*

{boxs}

{diamondsuit}

Heather F. Seidle, Pawel Bieganowski, , and Charles Brenner{ddagger}

Departments of Genetics and Biochemistry and Norris Cotton Cancer Center, Dartmouth Medical School, Lebanon, New Hampshire 03756

Abstract: Ataxia-oculomotor apraxia syndrome 1 is an early onset cerebellar ataxia that results from loss of function mutations in the APTX gene, encoding Aprataxin, which contains three conserved domains. The forkhead-associated domain of Aprataxin mediates protein-protein interactions with molecules that respond to DNA damage, but the cellular phenotype of the disease does not appear to be consistent with a major loss in DNA damage responses. Disease-associated mutations in Aprataxin target a histidine triad domain that is similar to Hint, a universally conserved AMP-lysine hydrolase, or truncate the protein NH2-terminal to a zinc finger. With novel fluorigenic substrates, we demonstrate that Aprataxin possesses an active-site-dependent AMP-lysine and GMP-lysine hydrolase activity that depends additionally on the zinc finger for protein stability and on the forkhead associated domain for enzymatic activity. Alleles carrying any of eight recessive mutations associated with ataxia and oculomotor apraxia encode proteins with huge losses in protein stability and enzymatic activity, consistent with a null phenotype. The mild presentation allele, APTX-K197Q, associated with ataxia but not oculomotor apraxia, encodes a protein with a mild defect in stability and activity, while enzyme encoded by the atypical presentation allele, APTX-R199H, retained substantial function, consistent with altered and not loss of activity. The data suggest that the essential function of Aprataxin is reversal of nucleotidylylated protein modifications, that all three domains contribute to formation of a stable enzyme, and that the in vitro behavior of cloned APTX alleles can score disease-associated mutations.


Received for publication March 16, 2005.

* This work was supported by research Grant CA75954 from the NCI, National Institutes of Health. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.


{boxs}

The on-line version of this article (available at http://www.jbc.org) contains supplemental Table 1 and Fig. 1.

{diamondsuit} This article was selected as a Paper of the Week.

{ddagger} To whom correspondence should be addressed: Norris Cotton Cancer Center, Dartmouth Medical School, Rubin 733-HB7937, Lebanon, NH 03756. Tel.: 603-653-9922; Fax: 603-653-9923; E-mail: charles.brenner{at}dartmouth.edu.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Genotype-phenotype correlations in early onset ataxia with ocular motor apraxia and hypoalbuminaemia.
A. Yokoseki, T. Ishihara, A. Koyama, A. Shiga, M. Yamada, C. Suzuki, Y. Sekijima, K. Maruta, M. Tsuchiya, H. Date, et al. (2011)
Brain 134, 1387-1399
   Abstract »    Full Text »    PDF »
To live or to die: a matter of processing damaged DNA termini in neurons.
S. F. El-Khamisy (2011)
EMBO Mol Med. 3, 78-88
   Abstract »    Full Text »    PDF »
Defective DNA Ligation during Short-Patch Single-Strand Break Repair in Ataxia Oculomotor Apraxia 1.
J. J. Reynolds, S. F. El-Khamisy, S. Katyal, P. Clements, P. J. McKinnon, and K. W. Caldecott (2009)
Mol. Cell. Biol. 29, 1354-1362
   Abstract »    Full Text »    PDF »
Aprataxin, causative gene product for EAOH/AOA1, repairs DNA single-strand breaks with damaged 3'-phosphate and 3'-phosphoglycolate ends.
T. Takahashi, M. Tada, S. Igarashi, A. Koyama, H. Date, A. Yokoseki, A. Shiga, Y. Yoshida, S. Tsuji, M. Nishizawa, et al. (2007)
Nucleic Acids Res. 35, 3797-3809
   Abstract »    Full Text »    PDF »
Actions of Aprataxin in Multiple DNA Repair Pathways.
U. Rass, I. Ahel, and S. C. West (2007)
J. Biol. Chem. 282, 9469-9474
   Abstract »    Full Text »    PDF »
Nucleolar localization of aprataxin is dependent on interaction with nucleolin and on active ribosomal DNA transcription.
O. J. Becherel, N. Gueven, G. W. Birrell, V. Schreiber, A. Suraweera, B. Jakob, G. Taucher-Scholz, and M. F. Lavin (2006)
Hum. Mol. Genet. 15, 2239-2249
   Abstract »    Full Text »    PDF »
Aprataxin Forms a Discrete Branch in the HIT (Histidine Triad) Superfamily of Proteins with Both DNA/RNA Binding and Nucleotide Hydrolase Activities.
A. W. Kijas, J. L. Harris, J. M. Harris, and M. F. Lavin (2006)
J. Biol. Chem. 281, 13939-13948
   Abstract »    Full Text »    PDF »

To Advertise     Find Products


Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882