Abstract
Mitochondrial fatty acid beta-oxidation is important for energy production, which is stressed by the different defects found in this pathway. Most of the enzyme deficiencies causing these defects are well characterized at both the protein and genomic levels. One exception is carnitine palmitoyltransferase I (CPT I) deficiency, of which until now no mutations have been reported although the defect is enzymatically well characterized. CPT I is the key enzyme in the carnitine-dependent transport across the mitochondrial inner membrane and its deficiency results in a decreased rate of fatty acid beta-oxidation. Here we report the first delineation of the molecular basis of hepatic CPT I deficiency in a new case. cDNA analysis revealed that this patient was homozygous for a missense mutation (D454G). The effect of the identified mutation was investigated by heterologous expression in yeast. The expressed mutant CPT IA displayed only 2% of the activity of the expressed wild-type CPT IA, indicating that the D454G mutation is the disease-causing mutation. Furthermore, in patient's fibroblasts the CPT IA protein was markedly reduced on immunoblot, suggesting that the mutation renders the protein unstable.
Full Text
The Full Text of this article is available as a PDF (182.1 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bergman A. J., Donckerwolcke R. A., Duran M., Smeitink J. A., Mousson B., Vianey-Saban C., Poll-The B. T. Rate-dependent distal renal tubular acidosis and carnitine palmitoyltransferase I deficiency. Pediatr Res. 1994 Nov;36(5):582–588. doi: 10.1203/00006450-199411000-00007. [DOI] [PubMed] [Google Scholar]
- Bougnères P. F., Saudubray J. M., Marsac C., Bernard O., Odièvre M., Girard J. Fasting hypoglycemia resulting from hepatic carnitine palmitoyl transferase deficiency. J Pediatr. 1981 May;98(5):742–746. doi: 10.1016/s0022-3476(81)80834-7. [DOI] [PubMed] [Google Scholar]
- Britton C. H., Mackey D. W., Esser V., Foster D. W., Burns D. K., Yarnall D. P., Froguel P., McGarry J. D. Fine chromosome mapping of the genes for human liver and muscle carnitine palmitoyltransferase I (CPT1A and CPT1B). Genomics. 1997 Feb 15;40(1):209–211. doi: 10.1006/geno.1996.4539. [DOI] [PubMed] [Google Scholar]
- Britton C. H., Schultz R. A., Zhang B., Esser V., Foster D. W., McGarry J. D. Human liver mitochondrial carnitine palmitoyltransferase I: characterization of its cDNA and chromosomal localization and partial analysis of the gene. Proc Natl Acad Sci U S A. 1995 Mar 14;92(6):1984–1988. doi: 10.1073/pnas.92.6.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown N. F., Anderson R. C., Caplan S. L., Foster D. W., McGarry J. D. Catalytically important domains of rat carnitine palmitoyltransferase II as determined by site-directed mutagenesis and chemical modification. Evidence for a critical histidine residue. J Biol Chem. 1994 Jul 22;269(29):19157–19162. [PubMed] [Google Scholar]
- Chase J. F., Tubbs P. K. Specific alkylation of a histidine residue in carnitine acetyltransferase by bromoacetyl-L-carnitine. Biochem J. 1970 Feb;116(4):713–720. doi: 10.1042/bj1160713. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
- Demaugre F., Bonnefont J. P., Colonna M., Cepanec C., Leroux J. P., Saudubray J. M. Infantile form of carnitine palmitoyltransferase II deficiency with hepatomuscular symptoms and sudden death. Physiopathological approach to carnitine palmitoyltransferase II deficiencies. J Clin Invest. 1991 Mar;87(3):859–864. doi: 10.1172/JCI115090. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DiMauro S., DiMauro P. M. Muscle carnitine palmityltransferase deficiency and myoglobinuria. Science. 1973 Nov 20;182(4115):929–931. doi: 10.1126/science.182.4115.929. [DOI] [PubMed] [Google Scholar]
- Falik-Borenstein Z. C., Jordan S. C., Saudubray J. M., Brivet M., Demaugre F., Edmond J., Cederbaum S. D. Brief report: renal tubular acidosis in carnitine palmitoyltransferase type 1 deficiency. N Engl J Med. 1992 Jul 2;327(1):24–27. doi: 10.1056/NEJM199207023270105. [DOI] [PubMed] [Google Scholar]
- Manning N. J., Olpin S. E., Pollitt R. J., Webley J. A comparison of [9,10-3H]palmitic and [9,10-3H]myristic acids for the detection of defects of fatty acid oxidation in intact cultured fibroblasts. J Inherit Metab Dis. 1990;13(1):58–68. doi: 10.1007/BF01799333. [DOI] [PubMed] [Google Scholar]
- McGarry J. D., Brown N. F. The mitochondrial carnitine palmitoyltransferase system. From concept to molecular analysis. Eur J Biochem. 1997 Feb 15;244(1):1–14. doi: 10.1111/j.1432-1033.1997.00001.x. [DOI] [PubMed] [Google Scholar]
- McGarry J. D., Leatherman G. F., Foster D. W. Carnitine palmitoyltransferase I. The site of inhibition of hepatic fatty acid oxidation by malonyl-CoA. J Biol Chem. 1978 Jun 25;253(12):4128–4136. [PubMed] [Google Scholar]
- Moon A., Rhead W. J. Complementation analysis of fatty acid oxidation disorders. J Clin Invest. 1987 Jan;79(1):59–64. doi: 10.1172/JCI112808. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schmalix W., Bandlow W. The ethanol-inducible YAT1 gene from yeast encodes a presumptive mitochondrial outer carnitine acetyltransferase. J Biol Chem. 1993 Dec 25;268(36):27428–27439. [PubMed] [Google Scholar]
- Smith P. K., Krohn R. I., Hermanson G. T., Mallia A. K., Gartner F. H., Provenzano M. D., Fujimoto E. K., Goeke N. M., Olson B. J., Klenk D. C. Measurement of protein using bicinchoninic acid. Anal Biochem. 1985 Oct;150(1):76–85. doi: 10.1016/0003-2697(85)90442-7. [DOI] [PubMed] [Google Scholar]
- Wanders R. J., IJlst L., Poggi F., Bonnefont J. P., Munnich A., Brivet M., Rabier D., Saudubray J. M. Human trifunctional protein deficiency: a new disorder of mitochondrial fatty acid beta-oxidation. Biochem Biophys Res Commun. 1992 Nov 16;188(3):1139–1145. doi: 10.1016/0006-291x(92)91350-y. [DOI] [PubMed] [Google Scholar]
- Wanders R. J., van Roermund C. W., van Wijland M. J., Schutgens R. B., Heikoop J., van den Bosch H., Schram A. W., Tager J. M. Peroxisomal fatty acid beta-oxidation in relation to the accumulation of very long chain fatty acids in cultured skin fibroblasts from patients with Zellweger syndrome and other peroxisomal disorders. J Clin Invest. 1987 Dec;80(6):1778–1783. doi: 10.1172/JCI113271. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yaffe M. P. Analysis of mitochondrial function and assembly. Methods Enzymol. 1991;194:627–643. doi: 10.1016/0076-6879(91)94046-f. [DOI] [PubMed] [Google Scholar]