Placental glutathione-S-transferase-pi mRNA is abundantly expressed in human skin

Four overlapping cDNA clones were isolated from a lambda gt11 human placenta cDNA library using purified human IgG antibody, from a patient with bullous pemphigoid. The sequence was homologous to human placenta glutathione-S-transferase-pi (GST-pi). Using the placenta clone, epidermal cDNA clones were isolated from a human keratinocyte library. Expression of GST-pi mRNA in human skin, cultured keratinocytes and fibroblasts, and disorders of squamous hyperplasia was demonstrated by Northern blotting and in situ hybridization. Human epidermal and placental cDNA clones hybridized to the same genomic DNA fragments. Hybridization of placental cDNA to interspecific somatic cell hybrids showed retention of chromosome 11, confirming the assignment of GST 3 to the long arm of chromosome 11 by molecular means. Anti-GST-pi antibody did not give a basement membrane zone pattern, although some normal and BP sera contained antibodies to GST-pi. Human skin expresses glutathione-S-transferase-pi, which belongs to an enzyme family important for detoxification and carcinogenesis.