Sequence of the complete cDNA and the 5′ structure of the human sucrase-isomaltase gene. Possible homology with a yeast glucoamylase
- Chantret, I MRC Human Biochemical Genetics Unit, The Galton Laboratory, University College London, 4 Stephenson Way, London NW1 2HE, U.K.
- Lacasa, M Université Pierre et Marie Curie, 2 Place Jussieu, 75005 Paris, France
- Chevalier, G Unité de Recherches sur la Differenciation Cellulaire Intestinale, INSERM U178, 16 avenue Paul-Vaillant Couturier, 94807 Villejuif Cedex, France
- Ruf, J Department of Biochemistry, Swiss Federal Institute of Technology, CH-8092 Zurich, Switzerland
- Islam, I MRC Human Biochemical Genetics Unit, The Galton Laboratory, University College London, 4 Stephenson Way, London NW1 2HE, U.K.
- Mantei, N Department of Biochemistry, Swiss Federal Institute of Technology, CH-8092 Zurich, Switzerland
- Edwards, Y MRC Human Biochemical Genetics Unit, The Galton Laboratory, University College London, 4 Stephenson Way, London NW1 2HE, U.K.
- Swallow, D MRC Human Biochemical Genetics Unit, The Galton Laboratory, University College London, 4 Stephenson Way, London NW1 2HE, U.K.
- Rousset, M Unité de Recherches sur la Differenciation Cellulaire Intestinale, INSERM U178, 16 avenue Paul-Vaillant Couturier, 94807 Villejuif Cedex, France
Published in:
- Biochemical Journal. - Portland Press Ltd.. - 1992, vol. 285, no. 3, p. 915-923
English
The complete sequence of the 6 kb cDNA and the 5′ genomic structure are reported for the gene coding for the human intestinal brush border hydrolase sucrase-isomaltase. The human sucrase-isomaltase cDNA shows a high level of identity (83%) with that of the rabbit enzyme, indicating that the protein shares the same structural domains in both species. In addition to the previously reported homology with lysosomal alpha-glucosidase, the sucrase and isomaltase subunits also appear to be homologous to a yeast glucoamylase. A 14 kb human genomic clone has been isolated which includes the first three exons and the first two introns of the gene, as well as 9.5 kb 5′ to the major start site of transcription. The first exon comprises 62 bp of untranslated sequence and the second starts exactly at the initiation ATG codon. Typical CAAT and TATA boxes are seen upstream of the first exon. A genetic polymorphism is described which involves a PstI site in the second intron. Southern blotting, sequencing and mRNA studies indicate that the structures of the sucrase-isomaltase gene and its mRNA are unaltered in the two human colon cancer cell lines Caco-2 and HT-29 in comparison with normal human small intestine.
- Language
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- English
- Open access status
- green
- Identifiers
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- DOI 10.1042/bj2850915
- ISSN 0264-6021
- Persistent URL
- https://sonar.ch/global/documents/140104
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