© 1995 Oxford University Press
Carnitine palmitoyltransferase II deficiency: structure of the gene and characterization of two novel disease-causing mutations
Divisione di Biochimica e Genetica, Istituto Nazionale Neurologico Carlo Besta, via Celona 11, 1–20133 Milan, Italy
*To whom correspondence should be addressed
Received August 10, 1994; Accepted October 14, 1994
Carnitine palmltoyltransferase (CPT) II deficiency is the most common inherited disorder of llpld metabolism affecting skeletal muscle. To facilitate the Identification of disease-causing mutations in the CPT II gene (CPT1), we have established the genomic organization of this gene. CPT1 spans approximately 20 kb of 1p32 and is composed of five exons ranging from 81 to 1305 bp. The sequences of the exon-lntron boundaries were determined for each exon and conformed to the consensus splice junction sequences. The 5‘ and 3’ untranslated regions In exon 1 and 5, respectively, were also determined, including the polyadenylation signal and the polyadenylation site. The mature transcript is predicted to be 3090 nt In length. CPT1 exons from CPT ll-deficient patients were amplified and directly sequenced. Two novel disease-causing mutations were identified and characterized. The first mutation was a C-665-to-A transversion in exon 1 resulting in a proline-to-histidine substitution at residue 50 of the protein (P50H). This amino acid substitution o-ccurs within a leucine-proline motif that is highly conserved in acyltransferases from different species. The mutation was detected in both alleles of patient 05SB of Italian ancestry, and in one allele of patients 11 EG, 38PG, and 26FD of Italian, Dutch, and French ancestry, respectively. The second mutation was a rare G-2173-to-A transition in exon 5 causing an aspartic-acid-to-asparaglne substitution at amino acid 553 (D553N) and the generation of a new Msel site. The mutation was detected only In one allele of patient 15MB, of Italian ancestry, who was also heterozygous for the common S113L substitution. Transfectlon experiments in COS cells demonstrated that both mutations drastically depressed the catalytic activity of CPT II. Biochemical characterization of P50H mutant CPT II in cultured cells from patient 05SB showed that the mutation does not affect substrate binding sites. Finally, immunoblot analysis demonstrated that both mutations were associated with markedly reduced steady-state level of the protein, thus indicating decreased stability of the mutant CPT II.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Deschauer, T. Wieser, and S. Zierz Muscle Carnitine Palmitoyltransferase II Deficiency: Clinical and Molecular Genetic Features and Diagnostic Aspects Arch Neurol, January 1, 2005; 62(1): 37 - 41. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Zheng, J. Dai, and G. Woldegiorgis Identification by Mutagenesis of a Conserved Glutamate (Glu487) Residue Important for Catalytic Activity in Rat Liver Carnitine Palmitoyltransferase II J. Biol. Chem., October 25, 2002; 277(44): 42219 - 42223. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Bruno, M. Bado, C. Minetti, G. Cordone, and S. DiMauro Novel Mutation in the CPT II Gene in a Child With Periodic Febrile Myalgia and Myoglobinuria J Child Neurol, June 1, 2000; 15(6): 390 - 393. [Abstract] [PDF]
|
|
|
|
 |
|
 D. Smail, L. Gambino, C. Boles, and G. D. Vladutiu Rapid, Cost-effective Gene Mutation Screening for Carnitine Palmitoyltransferase II Deficiency Using Whole Blood on Filter Paper Clin. Chem., November 1, 1999; 45(11): 2035 - 2038. [Full Text] [PDF]
|
|
|
|
 |
|
 M. R. Pierce, G. Pridjian, S. Morrison, and A. S. Pickoff Fatal Carnitine Palmitoyltransferase II Deficiency in a Newborn: New Phenotpic Features Clinical Pediatrics, January 1, 1999; 38(1): 13 - 20. [Abstract] [PDF]
|
|
|
|
 |
|
 C. Antozzi and M. Zeviani Cardiomyopathies in disorders of oxidative metabolism Cardiovasc Res, August 1, 1997; 35(2): 184 - 199. [Abstract] [Full Text] [PDF]
|
|