TY - JOUR
T1 - Dual function of cysteine rich domain (CRD) 1 of TNF receptor type 1
T2 - Conformational stabilization of CRD2 and control of receptor responsiveness
AU - Branschädel, Marcus
AU - Aird, Andrew
AU - Zappe, Andrea
AU - Tietz, Carsten
AU - Krippner-Heidenreich, Anja
AU - Scheurich, Peter
N1 - Funding Information:
We thank I.-W. von Broen (Knoll AG, Ludwigshafen, Germany) for recombinant TNF, D. Männel (University of Regensburg, Germany) for murine fibroblasts, and A. Strasser (The Walter and Eliza Hall Institute, Melbourne, Australia) for pEF PGKpuro. We thank Sylvia Willi and Jessica Tepperink for excellent technical assistance. This work was supported by the Deutsche Forschungsgemeinschaft grants KR 3307/1 to A.K.-H and SCHE 349/7-1 to P.S.
PY - 2010/3
Y1 - 2010/3
N2 - The proinflammatory cytokine Tumor Necrosis Factor (TNF) exists as a homotrimer, capable of binding three receptor molecules. However, signal competent ligand/receptor complexes form large clusters, likely to be stabilized by additional molecular interactions. Both TNF receptors, TNFR1 and TNFR2, contain four cysteine rich domains (CRD) in their extracellular parts. Previous work showed that the membrane distal CRD1 carries a homophilic interaction domain. Here, we investigated the functional role of CRD1 and its two submodules, A1CRD1 and B2CRD1, in a TNFR1-Fas chimera model system. Removal of CRD1 abolishes TNF binding. In line with these data, molecular dynamics simulations suggest that B2CRD1 of TNFR1 serves as a scaffold to stabilize CRD2 in a conformation necessary for high affinity ligand binding. Deletion of only the N-terminal half of CRD1 (ΔA1CRD1) of TNFR1 marginally affects ligand binding but abrogates responsiveness towards soluble TNF and reduces effectiveness as a dominant negative inhibitor of wild type TNFR1. A TNFR1-derived molecule containing the CRD1 from TNFR2 also shows reduced responsiveness to soluble TNF. These data strongly suggest that CRD1 is not only crucially involved in multimerization of unligated receptors, but is also directly involved in formation of signal competent ligand/receptor clusters, thereby controlling receptor responsiveness.
AB - The proinflammatory cytokine Tumor Necrosis Factor (TNF) exists as a homotrimer, capable of binding three receptor molecules. However, signal competent ligand/receptor complexes form large clusters, likely to be stabilized by additional molecular interactions. Both TNF receptors, TNFR1 and TNFR2, contain four cysteine rich domains (CRD) in their extracellular parts. Previous work showed that the membrane distal CRD1 carries a homophilic interaction domain. Here, we investigated the functional role of CRD1 and its two submodules, A1CRD1 and B2CRD1, in a TNFR1-Fas chimera model system. Removal of CRD1 abolishes TNF binding. In line with these data, molecular dynamics simulations suggest that B2CRD1 of TNFR1 serves as a scaffold to stabilize CRD2 in a conformation necessary for high affinity ligand binding. Deletion of only the N-terminal half of CRD1 (ΔA1CRD1) of TNFR1 marginally affects ligand binding but abrogates responsiveness towards soluble TNF and reduces effectiveness as a dominant negative inhibitor of wild type TNFR1. A TNFR1-derived molecule containing the CRD1 from TNFR2 also shows reduced responsiveness to soluble TNF. These data strongly suggest that CRD1 is not only crucially involved in multimerization of unligated receptors, but is also directly involved in formation of signal competent ligand/receptor clusters, thereby controlling receptor responsiveness.
KW - Pre-ligand binding assembly domain (PLAD)
KW - Signalling complex
KW - TNF
KW - TNF receptor
UR - http://www.scopus.com/inward/record.url?scp=71349086770&partnerID=8YFLogxK
U2 - 10.1016/j.cellsig.2009.10.011
DO - 10.1016/j.cellsig.2009.10.011
M3 - Article
C2 - 19879354
AN - SCOPUS:71349086770
SN - 0898-6568
VL - 22
SP - 404
EP - 414
JO - Cellular Signalling
JF - Cellular Signalling
IS - 3
ER -