Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Mar;82(3):661-72.
doi: 10.1016/j.ajhg.2007.12.024.

ADCK3, an ancestral kinase, is mutated in a form of recessive ataxia associated with coenzyme Q10 deficiency

Clotilde Lagier-Tourenne  1 , Meriem Tazir, Luis Carlos López, Catarina M Quinzii, Mirna Assoum, Nathalie Drouot, Cleverson Busso, Samira Makri, Lamia Ali-Pacha, Traki Benhassine, Mathieu Anheim, David R Lynch, Christelle Thibault, Frédéric Plewniak, Laurent Bianchetti, Christine Tranchant, Olivier Poch, Salvatore DiMauro, Jean-Louis Mandel, Mario H Barros, Michio Hirano, Michel Koenig
Affiliations

ADCK3, an ancestral kinase, is mutated in a form of recessive ataxia associated with coenzyme Q10 deficiency

Clotilde Lagier-Tourenne et al. Am J Hum Genet. 2008 Mar.

Abstract

Muscle coenzyme Q(10) (CoQ(10) or ubiquinone) deficiency has been identified in more than 20 patients with presumed autosomal-recessive ataxia. However, mutations in genes required for CoQ(10) biosynthetic pathway have been identified only in patients with infantile-onset multisystemic diseases or isolated nephropathy. Our SNP-based genome-wide scan in a large consanguineous family revealed a locus for autosomal-recessive ataxia at chromosome 1q41. The causative mutation is a homozygous splice-site mutation in the aarF-domain-containing kinase 3 gene (ADCK3). Five additional mutations in ADCK3 were found in three patients with sporadic ataxia, including one known to have CoQ(10) deficiency in muscle. All of the patients have childhood-onset cerebellar ataxia with slow progression, and three of six have mildly elevated lactate levels. ADCK3 is a mitochondrial protein homologous to the yeast COQ8 and the bacterial UbiB proteins, which are required for CoQ biosynthesis. Three out of four patients tested showed a low endogenous pool of CoQ(10) in their fibroblasts or lymphoblasts, and two out of three patients showed impaired ubiquinone synthesis, strongly suggesting that ADCK3 is also involved in CoQ(10) biosynthesis. The deleterious nature of the three identified missense changes was confirmed by the introduction of them at the corresponding positions of the yeast COQ8 gene. Finally, a phylogenetic analysis shows that ADCK3 belongs to the family of atypical kinases, which includes phosphoinositide and choline kinases, suggesting that ADCK3 plays an indirect regulatory role in ubiquinone biosynthesis possibly as part of a feedback loop that regulates ATP production.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Genotyping and Imaging Results of ARCA2 Families (A) SNP results of family 1 for the chromosome 1q41-q42 region. Graphic interface (HomoSNP software) for visualization of shared regions of homozygosity in consanguineous families. The top horizontal bar indicates the position of recessive-ataxia loci and genes. Subsequent bars indicate individual results of the children represented on the left. The regions with more than 25 consecutive homozygous SNP are in black. The regions of heterozygosity are in gray. The four affected siblings in family 1 share a region of homozygosity by descent on chromosome 1q41-q42. The AXPC1 locus is centromeric to this region of homozygosity. (B) Microsatellite analysis at chromosome 1q41-q42 in all available family 1 members. Markers are indicated on the left and are organized from top to bottom in the centromeric to telomeric order. Results of the four critical SNPs that define the two recombination boundaries are also indicated. Parental haplotypes linked with the disease are boxed. The region of homozygosity by descent is shaded in gray. Haplotype segregation confirms linkage between the 1q41-q42 locus and the disease in this family and defines a 12.6 Mb critical interval. (C) Sagittal T1-weighted brain magnetic resonance imaging of patient 4 (family 1) and patient 5 (family 2) showing cerebellar atrophy and mild cerebral atrophy.
Figure 2
Figure 2
Altered Splicing of ADCK3 Exon 11 in Family 1 and Exon 8 in Family 4 (A) Genomic sequence of ADCK3 exon-intron 11 boundary of a control individual and of the father and patient 3 of family 1. The patient is homozygous for the donor splice-site mutation 1398+2T→C. The healthy father is heterozygous for this mutation. (B) Analysis of RT-PCR products of patient 3 fibroblasts. The 1398+2T→C mutation affects exon 11 splicing and results in the production of two major bands on agarose gel, of 442 and 654 bp, respectively, and the product obtained from a control individual has a size of 584 bp. A faint band migrating between products 1 and 2 was shown by sequencing to correspond to heteroduplexes of products 1 and 2 (data not shown). (C) Sequence of product 1 after elution from agarose gel. Product 1 corresponds to skipping of exon 11 leading to a frameshift with a predicted truncated protein (p.Asp420TrpfsX40). (D) Sequence of product 2 after elution from agarose gel. Product 2 corresponds to the use of two cryptic splice sites in intron 11 leading to the insertion of 68 and 70 nucleotides (nt), respectively. The sequence of the two alternative products is indicated above the chromatogram. The respective position of the two cryptic donor splice sites is indicated below the chromatogram (underlined). In both cases, 21 amino acids are inserted before an in frame stop codon (circled) leading to a predicted truncated protein (Ile467AlafsX22). (E) Analysis of RT-PCR products of patient 7 lymphoblastoid cells. The c.993C→T mutation partially affects exon 8 splicing and results in the production of an abnormal product of 487 bp on agarose gel whereas only a normal product of 628 bp is seen in control lymphoblastoid cells. The abnormal product corresponds to skipping of exon 8 leading to an in-frame deletion of 47 amino acids (p.Lys314_Gln360 del). The faint intermediate band was shown by sequencing to correspond to heteroduplexes (data not shown).
Figure 3
Figure 3
Conservation of Amino Acids Mutated in ARCA2 Patients among ADCK3–ADCK4 Protein Sequences SPTREMBL accession numbers are indicated on the left. cabc1_human and q96d53_human correspond to ADCK3 and ADCK4, respectively. The following abbreviations are used: Xenla, Xenopus laevis; brare, Brachydanio rerio; tetng, Tetraodon nigroviridis; drome, Drosophila melanogaster; caeel, Caenorhabditis elegans; dicdi, Dictyostelium discoideum; yeast, Saccharomyces cerevisiae; schpo, Schizosaccharomyces pombe; arath, Arabidopsis thaliana; plaf7, Plasmodium falciparum; and jansc, Jannaschia sp. Amino acid numbering corresponds to human ADCK3. Dots and stars indicate variable degrees of phylogenetic conservation. Conserved amino acids are colored according to amino acid class (ClustalX). The N-terminal motif conserved in all members of the ADCK family (KxGK at positions 276–279) and the kinase motif VII (DFG at positions 507–509) are overlined in red. Nontruncating mutations identified in ARCA2 patients (p.Tyr514Cys, p.Gly549Ser, and p.Thr584 del) are indicated with arrows. (A) ClustalX sequence alignments of ADCK-specific N-terminal domain. (B) ClustalX sequence alignments of ADCK3–ADCK4-specific C-terminal domain.
Figure 4
Figure 4
Domain Organization and Phylogeny of ADCK Proteins (A) Motif conservation in typical protein kinases and in ADCK proteins. Consensus of the eight most conserved motifs of the typical protein kinases are indicated on top. Motifs that share homology with ADCKs motifs are indicated in red. Consensus of ADCK motifs are indicated below, with amino acid positions corresponding to human ADCK3. ADCK domains are depicted on the diagram as follows: blue rectangle, N-terminal domain conserved among all members of the ADCK family and containing the KxGQ motif; red ovals, the position of the conserved kinase motifs; yellow rectangle, C-terminal domain specific for each ADCK subgroups. The position of single-amino-acid changes found in ARCA2 patients is indicated at the bottom. (B) Phylogenetic tree of typical and atypical protein kinases. Typical protein kinases are clustered in a single group. ADCK proteins are clustered in four groups. The UbiB group corresponds to the bacterial ADCKs and to the chloroplastic bacterial-like ADCKs. The following abbreviations are used: PI4KII, phosphatidylinositol 4 kinase type 2; AFK, actin-fragmin kinase; ChaK, TRP channel kinase; PIPK, Phosphatidylinositol Phosphate Kinase; and PI3K-PI4K, phosphatidylinositol 3 and 4 kinases and related protein kinases.
Figure 5
Figure 5
Coq8 Null Yeast Phenotype Was Not Rescued by Transfection with Plasmids Carrying the Nontruncating Mutations Identified in ARCA2 Patients (A) Serial dilutions of the wild-type AW303, the coq8 null mutant (Dcoq8 = Delcoq8), and the mutant transformed with yeast wild-type COQ8 or with yeast coq8 nontruncating mutations were spotted on rich glucose (YPD) and rich ethanol/glycerol (YPEG) plates. Growth on nonfermentable carbon source (YPEG) was not restored by mutant coq8 but was rescued by the wild-type sequence and by the F372Y construct corresponding to the replacement of F372 by the homologous human amino acid (Y at the human position 514). (B) Oxygen consumption is impaired in coq8 null mutant (Dcoq8) and in Dcoq8 yeast transformed with plasmids carrying the deleterious mutations. (C) H2O2 production is elevated in coq8-deficient strains. Impaired oxygen consumption and increased H2O2 production are indicative of respiratory-chain dysfunction. (D) Exogenous coenzyme Q (CoQ6) respiratory-growth rescue. Rescue was similar in Dcoq8 strain and in Dcoq8 yeast transformed with mutated plasmids and was less efficient than rescue of coq7 and coq2 yeast mutants.
Figure 6
Figure 6
Absence of ADCK4 Induction in ADCK3-Deficient Fibroblasts ADCK4 mRNA levels in control fibroblasts (n = 4) and in patients 3, 5, and 6 fibroblasts were measured by quantitative real-time PCR. Expression levels of ADCK4 in patients 5 and 6 were slightly reduced. This slight reduction was not dependent on the type of housekeeping reference RNA used: (A) RPLP0 (ribosomal protein P0); (B) β-actin. Graphs represent means ± standard deviation (SD) of two independent experiments performed in duplicates.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Campuzano V., Montermini L., Molto M.D., Pianese L., Cossee M., Cavalcanti F., Monros E., Rodius F., Duclos F., Monticelli A. Friedreich's ataxia: Autosomal recessive disease caused by an intronic GAA triplet repeat expansion. Science. 1996;271:1423–1427. - PubMed
    1. Allikmets R., Raskind W.H., Hutchinson A., Schueck N.D., Dean M., Koeller D.M. Mutation of a putative mitochondrial iron transporter gene (ABC7) in X-linked sideroblastic anemia and ataxia (XLSA/A) Hum. Mol. Genet. 1999;8:743–749. - PubMed
    1. Nikali K., Suomalainen A., Saharinen J., Kuokkanen M., Spelbrink J.N., Lonnqvist T., Peltonen L. Infantile onset spinocerebellar ataxia is caused by recessive mutations in mitochondrial proteins Twinkle and Twinky. Hum. Mol. Genet. 2005;14:2981–2990. - PubMed
    1. Van Goethem G., Martin J.J., Dermaut B., Lofgren A., Wibail A., Ververken D., Tack P., Dehaene I., Van Zandijcke M., Moonen M. Recessive POLG mutations presenting with sensory and ataxic neuropathy in compound heterozygote patients with progressive external ophthalmoplegia. Neuromuscul. Disord. 2003;13:133–142. - PubMed
    1. Winterthun S., Ferrari G., He L., Taylor R.W., Zeviani M., Turnbull D.M., Engelsen B.A., Moen G., Bindoff L.A. Autosomal recessive mitochondrial ataxic syndrome due to mitochondrial polymerase gamma mutations. Neurology. 2005;64:1204–1208. - PubMed

Publication types

LinkOut - more resources