SPINK5 expression in keratinocytes

The balance between serine proteases, kallikreins (KLKs), and their inhibitor, Kazal type-5 (SPINK5), is important to maintain steady desquamation. To explore regulation of SPINK5 expression in skin, its promoters (nucleotide -676/-532 and -318/-146 from the major transcription start site) were subjected to luciferase assay because these two sides displayed high luciferase intensity in NHEK human keratinocyte. Electrophoretic mobility shift assay (EMSA) appeared specific nuclear protein binding to these two sides with almost the same size shift. However, in DNA foot printing, -676/-532 and -318/-146 had no specific sequence protection. Thus, at this moment, we could not confirm the major regulator of SPNK5 gene expression in skin. We, at least, acknowledge that the exploration of the relationship between KLKs and SPINK5 will give crucial information related to skin differentiation/proliferation. (partially supported by Grant-in-Aid C-264607944).