ISOLATION AND CHARACTERIZATION OF GENOMIC CLONES OF HUMAN SEQUENCES PRESUMABLY CODING FOR HAIR CYSTEINE-RICH PROTEINS

The major biochemical components of the mammalian hair are the interme diate filaments or keratins and the keratin associated proteins. Kerat in associated proteins are classified into two groups (high-cysteine a nd high glycine-tyrosine-rich polypeptides) according to the content o f these amino acids. Cysteine-rich group contains high sulphur (16-24% cysteine) and ultra-high sulphur (> 30% cysteine) proteins. We report here the identification of a human sequence presumably coding for a n ew ultra-high sulphur protein (hUHSp21) and the isolation and characte rization of four genomic clones containing six related sequences. We a lso discuss the possibility that all the genes encoding keratin associ ated proteins are evolutionary related. These human clones should prov ide useful molecular tools for studies of hair differentiation and und erstanding of the molecular basis of human trichothiodystrophy. Copyri ght (C) 1997 Elsevier Science Ireland Ltd.