GENOMIC STRUCTURE OF HUMAN CYSTATIN-A

Cystatin A is a cysteine proteinase inhibitor with a molecular mass of 11 kDa, and is located mainly in the keratohyaline granules of the st ratum granulosum and the cornified envelope of the stratum corneum in the epidermis. In this study, we demonstrated the genomic structure of this proteinase inhibitor in which there were three exons of 111 bp, 102 bp and 226 bp in length, while the lengths of the Ist and 2nd intr on were approximately 14 Kbp and 4 Kbp, respectively. The conserved se quence of QVVAG was encoded in the 2nd exon and was not inserted by an y introns. There were binding sites for SP-1 and AP-2 in the promoter region and an AP-1 binding site in the 1st intron. The successful ampl ification of each exon of cystatin A may possibly contribute to the de tection of the genomic abnormality of some skin disorders e.g. keratin ization disorder, chronic bacterial infection or photophobia.