A leucine----proline mutation in the H1 subdomain of keratin 1 causes epidermolytic hyperkeratosis.
Epidermolytic hyperkeratosis is an autosomal dominant disorder affecting the structural integrity of the suprabasal layers of human epidermis. We have recently documented in one family linkage of the disease phenotype to the cluster of type II keratins. We have now identified a leucine----proline amino acid substitution in the conserved H1 subdomain of keratin 1 that is present only in affected family members. Using a quantitative assay and electron microscopy with synthetic peptides, we show that, whereas the wild-type H1 peptide rapidly disassembles preformed keratin filaments in vitro, the mutant peptide does this far less efficiently. Therefore the mutation in keratin 1 is likely to cause defective keratin filaments and hence a defective cytoskeleton in the epidermal cells in vivo.
Chipev
C C
CC
Skin Biology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Korge
B P
BP
Markova
N
N
Bale
S J
SJ
DiGiovanna
J J
JJ
Compton
J G
JG
Steinert
P M
PM
D000595:Amino Acid Sequence; D001483:Base Sequence; D006801:Humans; D016113:Ichthyosiform Erythroderma, Congenital / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D007382:Intermediate Filaments / Q000737:chemistry; D007633:Keratins / Q000235:genetics*; D007930:Leucine; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011392:Proline
D007633:Keratins; D011392:Proline; D007930:Leucine