Transglutaminases (TGases), are 9 enzymes, cross-linking proteins by γ-glutamyl-E-lysine bonds. A new member of the TGase family, TGase 5, previously known also as TGase X, has been recently identified in differentiating keratinocytes. TGase 5 is expressed in different isoforms-full length, Δ3, Δ13 and Δ3Δ13 (missing the indicated exon)-; however only full length and Δ13 isoforms are active and are induced during the early stages of keratinocyte differentiation. TGase 5 is very efficient in using specific epidermal substrates such as loricrin, involucrin and SPRs. By indirect immunofluorescence analysis the antibodies decorated the upper layers of normal human epidermis, with consistent staining in the spinous and granular layers. TGase 5 contributes, as a secondary effect, to the hyperkeratotic phenotype in ichthyosis (both vulgaris and lamellar) and in psoriasis. In Darier disease, TGase 5 expression, as well as TGase 3, is completely miss-regulated, being overexpressed or totally absent in different areas of the same lesion.
|Number of pages||4|
|Publication status||Published - Jun 2002|
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology