REVIEWS  7th INTERNATIONAL CONFERENCE ON TRANSGLUTAMINASES AND PROTEIN CROSSLINKING REACTIONS
Ferrara (Italy), September 14-17, 2002 

Minerva Biotecnologica 2002 June;14(2):155-8

Copyright © 2003 EDIZIONI MINERVA MEDICA

lingua: Inglese

Role of transglutaminase 5 in epidermis

Candi E., Paradisi A., Terrinoni A., Cadot B., Rufini A., Puddu P., Merlino G.

IDI-IRCCS c/o Department of Experimental Medicine and Biochemical Sciences, University “Tor Vergata”, Rome

Trans­glu­ta­mi­nas­es (TGas­es), are 9 ­enzymes, ­cross-link­ing pro­teins by γ-glu­ta­myl-ε-­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.