IAP insertion in the murine LamB3 gene results in junctional epidermolysis bullosa.
The laminin-5 molecule functions in the attachment of various epithelia to basement membranes. Mutations in the laminin-5-coding genes have been associated with Herlitz junctional epidermolysis bullosa (HJEB), a severe and often lethal blistering disease of humans. Here we report the characterization of a spontaneous mouse mutant with an autosomal recessive blistering disease. These mice exhibit sub-epithelial blisters of the skin and mucosal surfaces and abnormal hemidesmosomes lacking sub-basal dense plates. By linkage analysis the genetic defect was localized to a 2-cM region on distal Chromosome (Chr) 1 where a laminin-5 subunit gene, LamB3, was previously localized. LamB3 mRNA and laminin-5 protein were undetectable by Northern blot analysis and immunohistochemical methods, respectively. DNA sequence analysis indicated that the LamB3 genetic defect resulted from disruption of the coding sequence by insertion of an intracisternal-A particle (IAP) at an exon/intron junction. These findings suggest a role for laminin-5 in hemidesmosome formation and indicate that the LamB3(IAP) mutant is a useful mouse model for HJEB.
Kuster
J E
JE
Division of Genetic Disorders, Laboratory of Developmental Genetics, Wadsworth Center, New York State Department of Health, P.O. Box 22002, Albany, New York 12201-2002, USA.
Guarnieri
M H
MH
Ault
J G
JG
Flaherty
L
L
Swiatek
P J
PJ
D000818:Animals; D015152:Blotting, Northern; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000378:metabolism*; D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D004195:Disease Models, Animal; D016109:Epidermolysis Bullosa, Junctional / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012867:Skin / Q000473:pathology / Q000648:ultrastructure; D012871:Skin Diseases / Q000235:genetics / Q000473:pathology; D000097794:Kalinin
D015815:Cell Adhesion Molecules; D004251:DNA Transposable Elements; D000097794:Kalinin