iRhoms are essential for TACE maturation
(A) Western blot of Concanavalin-A (ConA)-enriched protein extract from WT, iRhom1 KO (iR1−/−), iRhom2 KO (iR2−/−) and iRhom1/2 double KO (DKO) MEFs. Here and subsequently, immature and mature TACE are indicated by black and white arrowheads respectively.
(B) Western blot of ConA-enriched protein extract from iRhom2 KO MEFs containing two, one or no iRhom1 alleles.
(C) In vitro TACE activity assay on anti-TACE immunoprecipitates from WT, iRhom single KO, and DKO MEFs. *P<0.01, t test; pairwise comparisons between WT and each of the other treatments.
(D) Western blot showing TACE maturation in HEK293 ET cells stably expressing iRhom1, iRhom2 or the control polytopic proteins, tmem115 and Unc93b1. Expression of iRhoms, tmem115 and Unc93b1 was confirmed by anti-HA western.
(E) Western blot showing TACE binding in anti-HA immunoprecipitates from cells expressing HA-tagged iRhom1, iRhom2 or tmem115.
(F) Western blot showing TACE maturation in embryonic extracts from iRhom1−/+/iRhom2−/− versus double knockout embryos.