Distribution of p230, an alpha-spectrin-related polypeptide in normal and psoriatic epidermis and in cultured human keratinocytes.

We studied the localization of p230, an immunoanalogue of erythroid alpha-spectrin, in normal and psoriatic human epidermis and in cultured human keratinocytes. In immunofluorescence microscopy of frozen sections of normal skin a bright cytoplasmic staining was seen in the cortical area of the keratinocytes. Similar staining was also seen in lesional and uninvolved areas of psoriatic epidermis. The pericytoplasmic localization of p230 could also be seen in cultured human keratinocytes: a lamina-like reticular staining was seen mostly confined to the ventral cytoplasmic aspect and to junctional areas of the cells. Immunoblotting of electrophoretically separated polypeptides of epidermal cells revealed a distinct polypeptide of Mr 230 kD. The results indicate that alpha-spectrin-like polypeptides form a major cytoskeletal framework in human epidermal cells in both normal and psoriatic skin.