Author(s):
Cavadas, Miguel ; Oikonomidi, Ioanna ; Gaspar, Catarina J. ; Burbridge, Emma ; Badenes, Marina ; Félix, Inês ; Bolado, Alfonso ; Hu, Tianyi ; Bileck, Andrea ; Gerner, Christopher ; Domingos, Pedro M. ; von Kriegsheim, Alex ; Adrain, Colin
Date: 2017
Persistent ID: http://hdl.handle.net/10362/92266
Origin: Repositório Institucional da UNL
Subject(s): 14-3-3; ADAM metalloproteases; ADAM17/TACE; ectodomain shedding; EGFR; iRhom2; MAP kinases; TNF; Biochemistry, Genetics and Molecular Biology(all)
Description
Cell surface metalloproteases coordinate signaling during development, tissue homeostasis, and disease. TACE (TNF-α-converting enzyme), is responsible for cleavage (“shedding”) of membrane-tethered signaling molecules, including the cytokine TNF, and activating ligands of the EGFR. The trafficking of TACE within the secretory pathway requires its binding to iRhom2, which mediates the exit of TACE from the endoplasmic reticulum. An important, but mechanistically unclear, feature of TACE biology is its ability to be stimulated rapidly on the cell surface by numerous inflammatory and growth-promoting agents. Here, we report a role for iRhom2 in TACE stimulation on the cell surface. TACE shedding stimuli trigger MAP kinase-dependent phosphorylation of iRhom2 N-terminal cytoplasmic tail. This recruits 14-3-3 proteins, enforcing the dissociation of TACE from complexes with iRhom2, promoting the cleavage of TACE substrates. Our data reveal that iRhom2 controls multiple aspects of TACE biology, including stimulated shedding on the cell surface. Cavadas et al. examine how the metalloprotease TACE is stimulated to shed its substrates, observing that iRhom2, a molecule essential for TACE trafficking, is phosphorylated in response to stimulants (PMA, TLRs, and GPCRs). iRhom phosphorylation requires MAPKs and recruits 14-3-3, which causes iRhom2/TACE dissociation, enabling TACE to cleave its substrates.
