Isolation and characterization of the murine alpha-L-iduronidase cDNA
Mucopolysaccharidosis I (MPS I) are a group of disorders caused by deficiency of the lysosomal enzyme alpha-L-iduronidase. The characterization of the human gene and the identification of mutations underlying MPS I in humans has led to the delineation of the molecular basis of this disorder. Model systems are now needed for the evaluation and development of therapeutics for this disorder. Both canine and feline models for MPS type I have been described but only the canine gene has been isolated and characterized. We report here the cloning and expression of the murine alpha-L-iduronidase cDNA. The murine cDNA was obtained by screening a mouse liver cDNA library with a probe from the human cDNA. The full length murine cDNA is 3120 base pairs in length and thus is considerably larger than both the human and canine transcripts. The increase in size is due to a 1.2 kb 3{prime} untranslated region in the murine cDNA that contains a CA dinucleotide repeat. Within the coding region the murine cDNA shows sequences. At the protein level the murine protein shows 77% similarity with the human protein and 75% similarity with the canine protein. There are significant differences in both the start and stop sites with the murine protein 9 amino acids shorter at both the N terminal signal peptide region and the C terminus. Expression of the murine cDNA in COS-1 cells resulted in a 20 fold increase in intracellular alpha-L-iduronidase activity as well as the detection of considerable enzyme activity in the culture medium. Comparison of the reported missense mutations underlying MPS I in humans (A75T, H82P, R89Q, L218P, P533R, Q310X, T366P) has shown conservation of these amino acid residues in the murine protein. The isolation of the murine iduronidase cDNA will now allow for the development of a murine model for MPS I.
- OSTI ID:
- 134626
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-1363
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Molecular genetic analysis of a patient with Hunter syndrome (mucopolysaccharidosis type II) and {alpha}-L-iduronidase pseudodeficiency
Mucopolysaccharidosis IVA: Identification of a common missense mutation I113F in the N-Acetylgalactosamine-6-sulfate sulfatase gene