Repertoire of mouse ectodysplasin-A (EDA-A) isoforms.

Mutations in ectodysplasin-A (EDA) cause loss of hair, sweat glands, and teeth in man and mouse. Isoform EDA-A1 protein shows partial rescue of the affected Tabby mouse phenotypes, suggesting that other isoforms may be required for full function. We describe genomic structure for five EDA isoforms, EDA-A1', A5, A5', A6, and A6', in addition to the previously known EDA-A1, A2, A3, and A4. The novel isoforms together account for approximately 12% of total EDA transcripts. The most different, EDA-A6 and A6', which lack the critical domain for interaction with NF-kappaB-activating receptors, were nevertheless confirmed to be present in mouse and human skin tissue. Other isoforms, EDA-A5 and A5', for example, activated NF-kappaB through receptors EDAR and XEDAR. These properties make new isoforms candidates for modulators of EDA function.