TY - JOUR
T1 - Identification of a mutation that causes exon skipping during collagen pre-mRNA splicing in an Ehlers-Danlos syndrome variant
AU - Weil, D.
AU - Bernard, M.
AU - Combates, N.
AU - Wirtz, M. K.
AU - Hollister, D. W.
AU - Steinmann, B.
AU - Ramirez, F.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1988
Y1 - 1988
N2 - Recent biochemical studies have shown that the fibroblasts from a patient with Ehlers-Danlos Syndrome Type VIIB produce nearly equal amounts of normal and shortened pro-α2(I) collagen chains (Wirtz., M.K., Glanville, R.W., Steinmann, B., Rao, V.H., and Hollister, D. (1987) J. Biol. Chem. 262, 16376-16385). Compositional and sequencing studies of the abnormal pro-α2(I) chain identified an interstitial deletion of 18 residues corresponding to the N-telopeptide of the collagen molecule. Since this region is encoded by a 54-base pair exon, number 6, the protein defect could have been caused by gene deletion, abnormal pre-mRNA splicing, or both. Here, in order to elucidate the molecular nature of this mutation we have analyzed the sequences of pro-α2(I) collagen cDNA and genomic clones obtained from RNA and DNA of the patient's fibroblasts. Using oligomer-specific cloning we identified a cDNA that contains a 54-base pair deletion corresponding precisely to the sequence of exon 6. Identification of the normal gene was based on the finding of an identical sequence polymorphism in a normal cDNA and in the genomic clone derived from one of the two collagen alleles. The other gene, instead, displayed a base substitution (T to C) in the obligatory GT dinucleotide of the 5' splice-site sequence of intron 6. Analysis of nearly 100 base pairs immediately 5' to exons 5, 6, and 7, and 3' to exons 5 and 7 did not reveal any additional change. Therefore, the data strongly suggest that the observed GT-to-GC transition at the splice donor site of intron 6 generates an abnormally spliced mRNA in which the sequence of exon 5 is joined to the sequence of exon 7. Since skipping of exon 6 does not interfere with the coding frame of the mRNA, the resulting shortened polypeptide, albeit utilized in the assembly of a procollagen trimer, ultimately causes the Ehlers-Danlos Syndrome Type VII phenotype.
AB - Recent biochemical studies have shown that the fibroblasts from a patient with Ehlers-Danlos Syndrome Type VIIB produce nearly equal amounts of normal and shortened pro-α2(I) collagen chains (Wirtz., M.K., Glanville, R.W., Steinmann, B., Rao, V.H., and Hollister, D. (1987) J. Biol. Chem. 262, 16376-16385). Compositional and sequencing studies of the abnormal pro-α2(I) chain identified an interstitial deletion of 18 residues corresponding to the N-telopeptide of the collagen molecule. Since this region is encoded by a 54-base pair exon, number 6, the protein defect could have been caused by gene deletion, abnormal pre-mRNA splicing, or both. Here, in order to elucidate the molecular nature of this mutation we have analyzed the sequences of pro-α2(I) collagen cDNA and genomic clones obtained from RNA and DNA of the patient's fibroblasts. Using oligomer-specific cloning we identified a cDNA that contains a 54-base pair deletion corresponding precisely to the sequence of exon 6. Identification of the normal gene was based on the finding of an identical sequence polymorphism in a normal cDNA and in the genomic clone derived from one of the two collagen alleles. The other gene, instead, displayed a base substitution (T to C) in the obligatory GT dinucleotide of the 5' splice-site sequence of intron 6. Analysis of nearly 100 base pairs immediately 5' to exons 5, 6, and 7, and 3' to exons 5 and 7 did not reveal any additional change. Therefore, the data strongly suggest that the observed GT-to-GC transition at the splice donor site of intron 6 generates an abnormally spliced mRNA in which the sequence of exon 5 is joined to the sequence of exon 7. Since skipping of exon 6 does not interfere with the coding frame of the mRNA, the resulting shortened polypeptide, albeit utilized in the assembly of a procollagen trimer, ultimately causes the Ehlers-Danlos Syndrome Type VII phenotype.
UR - http://www.scopus.com/inward/record.url?scp=0023937688&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023937688&partnerID=8YFLogxK
M3 - Article
C2 - 2454224
AN - SCOPUS:0023937688
SN - 0021-9258
VL - 263
SP - 8561
EP - 8564
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 18
ER -