Key points are not available for this paper at this time.
Receptor activator of NF-κB (RANK) is a recently identified member of the tumor necrosis factor receptor superfamily and is expressed on activated T cells and dendritic cells. Its cognate ligand (RANKL) plays significant roles in the activation of dendritic cell function and osteoclast differentiation. We demonstrate here the interaction of RANK with tumor necrosis factor receptor-associated factors (TRAFs) 1, 2, 3, 5, and 6 both in vitro and in cells. Mapping of the structural requirements for TRAF/RANK interaction revealed multiple TRAF binding sites clustered in two distinct domains in the RANK cytoplasmic tail. These TRAF binding domains were shown to be functionally important for the RANK-dependent induction of NF-κB and c-Jun NH2-terminal kinase activities. Site-directed mutagenesis demonstrated that these TRAF binding sites exhibited selective binding for different TRAF proteins. In particular, TRAF6 interacted with membrane-proximal determinants distinct from those binding TRAFs 1, 2, 3, and 5. When this membrane-proximal TRAF6 interaction domain was deleted, RANK-mediated NF-κB signaling was completely inhibited while c-Jun NH2-terminal kinase activation was partially inhibited. An NH2-terminal truncation mutant of TRAF6 inhibited RANKL-mediated NF-κB activation, but failed to affect constitutive signaling induced by receptor overexpression, revealing a selective role for TRAF6 in ligand-induced activation events. Receptor activator of NF-κB (RANK) is a recently identified member of the tumor necrosis factor receptor superfamily and is expressed on activated T cells and dendritic cells. Its cognate ligand (RANKL) plays significant roles in the activation of dendritic cell function and osteoclast differentiation. We demonstrate here the interaction of RANK with tumor necrosis factor receptor-associated factors (TRAFs) 1, 2, 3, 5, and 6 both in vitro and in cells. Mapping of the structural requirements for TRAF/RANK interaction revealed multiple TRAF binding sites clustered in two distinct domains in the RANK cytoplasmic tail. These TRAF binding domains were shown to be functionally important for the RANK-dependent induction of NF-κB and c-Jun NH2-terminal kinase activities. Site-directed mutagenesis demonstrated that these TRAF binding sites exhibited selective binding for different TRAF proteins. In particular, TRAF6 interacted with membrane-proximal determinants distinct from those binding TRAFs 1, 2, 3, and 5. When this membrane-proximal TRAF6 interaction domain was deleted, RANK-mediated NF-κB signaling was completely inhibited while c-Jun NH2-terminal kinase activation was partially inhibited. An NH2-terminal truncation mutant of TRAF6 inhibited RANKL-mediated NF-κB activation, but failed to affect constitutive signaling induced by receptor overexpression, revealing a selective role for TRAF6 in ligand-induced activation events. receptor activator of NF-κB tumor necrosis factor TNF receptor TNF receptor-associated factor RANK ligand electrophoretic mobility shift assay dendritic cell glutathione S-transferase TRAF binding site c-Jun NH2-terminal kinase polymerase chain reaction polyacrylamide gel electrophoresis interleukin 4-morpholinepropanesulfonic acid. RANK1and RANK ligand (RANKL) are a recently described cognate pair of the TNF receptor/ligand superfamilies (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar). The receptor (RANK) cDNA was originally isolated from a human DC cDNA library and shows the highest homology (40% identity within the extracellular domain) with CD40 among TNFR family members. Among antigen-presenting cells, RANK surface expression appears to be specific to DC and can be significantly up-regulated by a DC activator, CD40 ligand. However, RANK protein expression is not DC-specific as RANK is also expressed on human peripheral blood T cells treated with phytohemagglutinin and IL-4 or transforming growth factor-β (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar). In contrast to the relatively specific protein expression, RANK mRNA is broadly expressed in a variety of tissues including skeletal muscle, thymus, liver, colon, adrenal gland, and small intestine. The discrepancy between mRNA and surface protein expression suggests complex post-transcriptional regulatory mechanisms for RANK expression. Cells may therefore express RANK after discrete activation or differentiation conditions. The identification of the cognate ligand for RANK (RANKL) was performed by direct expression cloning from a mouse CD4+ thymoma cell line (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar). The same ligand has also been identified by screening a T cell hybridoma cell line (termed TRANCE) (2Wong B.R. Rho J. Arron J. Robinson E. Orlinick J. Chao M. Kalachikov S. Cayani E. Bartlett III, F.S. Frankel W.N. Lee S.Y. Choi Y. J. Biol. Chem. 1997; 272: 25190-25194Abstract Full Text Full Text PDF PubMed Scopus (915) Google Scholar) and as an osteoclast differentiation factor (3Yasuda H. Shima N. Nakagawa N. Yamaguchi K. Kinosaki M. Mochizuki S. Tomoyasu A. Yano K. Goto M. Murakami A. Tsuda E. Morinaga T. Higashio K. Udagawa N. Takahashi N. Suda T. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 3597-3602Crossref PubMed Scopus (3571) Google Scholar) whose activity can be inhibited by a soluble TNF receptor family member, osteoprotegerin (4Lacey D.L. Timms E. Tan H.-L. Kelley M.J. Dunstan C.R. Burgess T. Elliott R. Colombero A. Elliott G. Scully S. Hsu H. Sullivan J. Hawkins N. Davy E. Capparelli C. Eli A. Qian Y.-X. Kaufman S. Sarosi I. Shalhoub V. Senaldi G. Guo J. Delaney J. Boyle W.J. Cell. 1998; 93: 165-176Abstract Full Text Full Text PDF PubMed Scopus (4627) Google Scholar). RANKL mRNA appears to have a more restricted tissue expression pattern than RANK and has only been detected in mouse thymus, lymph node, spleen (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar, 2Wong B.R. Rho J. Arron J. Robinson E. Orlinick J. Chao M. Kalachikov S. Cayani E. Bartlett III, F.S. Frankel W.N. Lee S.Y. Choi Y. J. Biol. Chem. 1997; 272: 25190-25194Abstract Full Text Full Text PDF PubMed Scopus (915) Google Scholar), bone marrow stroma, and trabecular bone (3Yasuda H. Shima N. Nakagawa N. Yamaguchi K. Kinosaki M. Mochizuki S. Tomoyasu A. Yano K. Goto M. Murakami A. Tsuda E. Morinaga T. Higashio K. Udagawa N. Takahashi N. Suda T. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 3597-3602Crossref PubMed Scopus (3571) Google Scholar). Specific lymphoid cells that express RANKL include both CD4+ and CD8+ T cells and B cell progenitors (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar, 2Wong B.R. Rho J. Arron J. Robinson E. Orlinick J. Chao M. Kalachikov S. Cayani E. Bartlett III, F.S. Frankel W.N. Lee S.Y. Choi Y. J. Biol. Chem. 1997; 272: 25190-25194Abstract Full Text Full Text PDF PubMed Scopus (915) Google Scholar). TCR stimulation of T cell hybridomas leads to the rapid induction of RANKL/TRANCE mRNA (2Wong B.R. Rho J. Arron J. Robinson E. Orlinick J. Chao M. Kalachikov S. Cayani E. Bartlett III, F.S. Frankel W.N. Lee S.Y. Choi Y. J. Biol. Chem. 1997; 272: 25190-25194Abstract Full Text Full Text PDF PubMed Scopus (915) Google Scholar). Studies of the biological function of the RANK/RANKL interaction demonstrate that RANKL promotes the survival of transforming growth factor-β-treated T cells and increases the clustering and allo-stimulatory capacity of human DC (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar). RANKL may promote DC survival by a BCL-XL-dependent mechanism (5Wong B.R. Josien R. Lee S.Y. Sauter B. Li H.-L. Steinman R.M. Choi Y. J. Exp. Med. 1997; 186: 2075-2080Crossref PubMed Scopus (752) Google Scholar). The recent characterization of RANKL as an essential factor for osteoclast differentiation and activation (3Yasuda H. Shima N. Nakagawa N. Yamaguchi K. Kinosaki M. Mochizuki S. Tomoyasu A. Yano K. Goto M. Murakami A. Tsuda E. Morinaga T. Higashio K. Udagawa N. Takahashi N. Suda T. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 3597-3602Crossref PubMed Scopus (3571) Google Scholar, 4Lacey D.L. Timms E. Tan H.-L. Kelley M.J. Dunstan C.R. Burgess T. Elliott R. Colombero A. Elliott G. Scully S. Hsu H. Sullivan J. Hawkins N. Davy E. Capparelli C. Eli A. Qian Y.-X. Kaufman S. Sarosi I. Shalhoub V. Senaldi G. Guo J. Delaney J. Boyle W.J. Cell. 1998; 93: 165-176Abstract Full Text Full Text PDF PubMed Scopus (4627) Google Scholar) demonstrates additional activities of RANKL on myeloid lineages. Although the role of RANK in bone resorption/osteoclast differentiation has not been elucidated, RANK and its ligand appear to be important in the regulation of T cell/DC interactions and may also function in other important cellular differentiation processes. Although the physiological functions of RANK and RANKL have been investigated, the mechanisms of RANK signal transduction have not been intensively studied. Multimerization of TNFR family members (as a result of ligand binding or receptor overexpression) is thought to lead to receptor activation and signal transduction, perhaps by revealing binding domains for enzymes or adaptor proteins. In recent years, substantial progress has been made to define the cytoplasmic proteins that function as adaptors (TRAFs 1–6, TRADD, FADD) or as serine/threonine kinases (RIP) and link TNF receptor stimulation with the induction of cell death, Jun kinase (JNK) or NF-κB activation pathways (reviewed in Ref. 6Darnay B.G. Aggarwal B.B. J. Leukocyte. Biol. 1997; 61: 559-566Crossref PubMed Scopus (168) Google Scholar). RANK stimulation leads to activation of the nuclear transcription complex NF-κB in RANK-expressing human T cells and transfected 293 cells (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar) and JNK (2Wong B.R. Rho J. Arron J. Robinson E. Orlinick J. Chao M. Kalachikov S. Cayani E. Bartlett III, F.S. Frankel W.N. Lee S.Y. Choi Y. J. Biol. Chem. 1997; 272: 25190-25194Abstract Full Text Full Text PDF PubMed Scopus (915) Google Scholar) in mouse thymocytes. However, the RANK cytoplasmic determinants or the cytoplasmic effector/adaptor proteins necessary for downstream signaling have not been described. While the 383-amino acid cytoplasmic domain of RANK is the largest of any known TNFR, it does not contain sequences suggestive of catalytic activity or significant homology with any known protein. The amino acid sequences of the human and mouse RANK cytoplasmic domains include multiple sections that show striking homology (64% amino acid identity and 78% similarity) between species (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar), suggesting a conserved functional role for these structures. Since many members of the TNFR superfamily that do not contain a death domain (p80 TNFR, CD40, CD30, CD27, OX40, 4–1BB, LTβR, HVEM) interact with the cytoplasmic adaptor/effector TRAF proteins (7Rothe M. Sarma V. Dixit V.M. Goeddel D.V. Science. 1995; 269: 1424-1427Crossref PubMed Scopus (978) Google Scholar, 8Ishida T. Mizushima S. Azuma S. Kobayashi N. Tojo T. Suzuki K. Aizawa S. Watanabe T. Mosialos G. Kieff E. T. J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, H. I. Colombero A. Elliott R. Kelley M. Boyle W.J. J. Biol. Chem. 1997; 272: Full Text Full Text PDF PubMed Scopus Google Scholar, M. M. A. J. Biol. Chem. 1997; 272: Full Text Full Text PDF PubMed Scopus Google Scholar, M.C. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, Cell. Biol. 1998; PubMed Google Scholar, H. H. S. M. T. M. C. D. H. K. J. Biol. Chem. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar), an to define TRAF binding to In this have identified the structural and functional of RANK for both NF-κB and multiple distinct and domains of binding TRAF proteins and downstream In TRAF6 appears to RANK function determinants of other TRAF proteins and plays a selective role in of RANK were by and were by the The were the the and The of of the was by cytoplasmic domain was as a proteins were expressed and from by to PubMed Scopus Google Scholar). protein of were TRAF were the or was in vitro with or polymerase the to the was in the of of The of the protein was by and protein were after a were binding and by with of in vitro binding protein was with of the protein to and with for The protein were by in binding and by were with to of treated with and to for was in with the human a NF-κB binding site G. 1997; PubMed Scopus Google Scholar) to a cells were transfected by the with the or in with human RANK cDNA in B. T. D. A. D. J. C. B. D. Cosman D. Cell. Full Text PDF PubMed Scopus Google Scholar). and of TRAF an NH2-terminal were by and The NH2-terminal the amino (as described in Ref. M. W.J. Goeddel D.V. Cell. Full Text PDF PubMed Scopus Google Scholar). The truncation of was as described H. H. L. H. K. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). The TRAF6 the and of the J. M. T. Goeddel D.V. Nature. PubMed Scopus Google Scholar). was as an for for were by the of were performed in after cells were treated with human RANKL for human RANKL is an NH2-terminal of a domain W.C. S. R. PubMed Scopus Google Scholar) with of RANKL (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar). activity in cell was to a activities were to the were from 293 cells transfected with or cytoplasmic of RANK or after as described W.C. 1995; Full Text PDF PubMed Scopus Google Scholar). an NF-κB binding site were with and with of nuclear for of the reaction was by with of or a NF-κB binding The were by in and by JNK cell were from 293 cells after Cells were in a and the and were with of and from The were in two with and in assay JNK activity was by an assay of and of as in of assay for were on and by In to define TRAFs may to of the known TRAFs was and in vitro in the of and were performed to the interaction with a the RANK cytoplasmic domain amino was to interact with TRAFs 1, 2, 3, 5, and 6 in a specific We binding of RANK with TRAFs 1, 2, 3, and interaction with and binding with In of the TRAFs interacted with a protein or a cytoplasmic domain protein not that the in vitro interaction of TRAFs with RANK also in cells, were performed in 293 cells with RANK and TRAFs and revealed that RANK with the same of TRAFs (TRAFs 1, 2, 3, 5, and but not not the binding sites in the RANK cytoplasmic were and the in vitro binding were In contrast to the RANK cytoplasmic a that the amino was to interact with TRAFs 1, 2, 3, and and TRAF6 binding was by The of an additional amino or amino in TRAF6 binding activity to RANK However, the amino were the interaction with TRAF6 was These demonstrate that two of the RANK cytoplasmic domain are of binding TRAF proteins. of the protein within the acid RANK domain of TRAF binding revealed multiple with homology with TRAF binding sites in other TNFR family members. We two RANK in this and to to the in CD40 and Y. S. 1997; PubMed Scopus Google Scholar) as as the H. I. Colombero A. Elliott R. Kelley M. Boyle W.J. J. Biol. Chem. 1997; 272: Full Text Full Text PDF PubMed Scopus Google Scholar) and the Cell. Biol. 1998; PubMed Google Scholar). these in RANK were important for TRAF amino within these with and TRAF of amino to within the RANK cytoplasmic domain significantly and binding to that with the of and TRAF6 were of with in a of binding the binding of any other These two for binding TRAFs 1, 2, 3, and 5. of these two sites and of TRAFs 1, 2, and binding was more suggesting that these two sites in of the or in TRAF6 that TRAF6 distinct in We have that activation of RANK by receptor or by RANKL leads to the activation of NF-κB (1Anderson D.M. Maraskovsky E. Billingsley W.L. Dougall W.C. Tometsko M.E. Roux E.R. Teepe M.C. Dubose R.F. Cosman D. Galibert L. Nature. 1997; 390: 175-179Crossref PubMed Scopus (1946) Google Scholar). In to the role of RANK cytoplasmic sequences and other cellular protein in RANK a We activity from RANK expression in the 293 cells. activity in a RANK induction was with of RANK transfected These that of RANK can lead to NF-κB to that with other TNFR family TNFR and CD40 (7Rothe M. Sarma V. Dixit V.M. Goeddel D.V. Science. 1995; 269: 1424-1427Crossref PubMed Scopus (978) Google Scholar, G. D. PubMed Scopus Google Scholar). signaling was by the a RANK of RANK and the of RANKL the more than that after with RANK only We also demonstrated that soluble RANKL protein activity of RANK or RANKL were also with a NF-κB not that these are to NF-κB The interaction of TRAFs with multiple RANK cytoplasmic domains and the of TRAFs to NF-κB activation (7Rothe M. Sarma V. Dixit V.M. Goeddel D.V. Science. 1995; 269: 1424-1427Crossref PubMed Scopus (978) Google Scholar, Goeddel D.V. M. Proc. Natl. Acad. Sci. U. S. A. 1997; PubMed Scopus Google Scholar) suggests that the of may this cytoplasmic of RANK were expressed in 293 cells and activity was expression of RANK were by of proteins and by not of 293 cells with the RANK the amino in NF-κB activity in the of RANKL activation However, RANKL of RANK cells induced NF-κB activation to to that with of sequences on the constitutive and RANKL-mediated activity the of amino RANK completely both constitutive signaling and to The of RANK cytoplasmic determinants on NF-κB activation as by direct these that RANK two domains and within its cytoplasmic important for NF-κB These two RANK functional with the two domains that affect binding of TRAFs 1, 2, 3, 5, and 6 and TRAF6 the of RANK domains important for NF-κB signaling between RANK signal transduction as a result of receptor and RANKL signaling from RANK was significantly by the of the amino However, RANKL-mediated signaling was only by the of amino to the of direct TRAF6 binding in In the of receptor expression, TRAFs 2, 5, and 6 activated NF-κB not as has been (7Rothe M. Sarma V. Dixit V.M. Goeddel D.V. Science. 1995; 269: 1424-1427Crossref PubMed Scopus (978) Google Scholar, Goeddel D.V. M. Proc. Natl. Acad. Sci. U. S. A. 1997; PubMed Scopus Google Scholar). the functional of these TRAFs in RANK-mediated NF-κB activation, 293 cells were with RANK and expression NH2-terminal of and of has been demonstrated to NF-κB signaling in a (7Rothe M. Sarma V. Dixit V.M. Goeddel D.V. Science. 1995; 269: 1424-1427Crossref PubMed Scopus (978) Google Scholar, H. H. L. H. K. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, Goeddel D.V. M. Proc. Natl. Acad. Sci. U. S. A. 1997; PubMed Scopus Google Scholar). of the of TRAFs 2, 5, or 6 inhibited the activity in a However, only and constitutive signaling from the The TRAF6 inhibited but not constitutive revealing a specific role for TRAF6 in human RANK receptor lead to activation of protein kinase were performed in 293 cells of RANK significantly induced JNK activity to that with or of TNFR of the amino of RANK the of JNK The JNK activity was completely inhibited after the truncation of amino in the RANK cytoplasmic domain These demonstrate that two distinct RANK cytoplasmic domains and functional roles in JNK activation, to the domains necessary for NF-κB activation described and The of RANK truncation demonstrate that and to JNK and NF-κB However, of these RANK with RANKL revealed that the TRAF6 in vitro plays the role in NF-κB the role of this domain an the TRAF6 binding site and the downstream domains of with TRAFs 1, 2, 3, and and shown in was NF-κB activation from or RANKL activation of RANK as with of was to that of the RANK has been shown to be of binding any TRAF result the for TRAF6 binding to this for NF-κB activation and that the downstream and function to NF-κB of RANK JNK activity to that with RANK in contrast to the NF-κB this activation of JNK the JNK activity was also exhibited after RANKL activation of the RANK this have shown to be of binding TRAF6 is for NF-κB and to JNK activation by The TNFR superfamily of proteins that can including and survival receptor TNFR family member a death domain has been shown to interact with cytoplasmic TRAF adaptor proteins or However, signaling pathways by different TNFR members are and The of RANK signaling TRAFs may be by multiple the cellular and of the TRAF the of TRAFs for cytoplasmic proteins including other and (reviewed in Ref. 6Darnay B.G. Aggarwal B.B. J. Leukocyte. Biol. 1997; 61: 559-566Crossref PubMed Scopus (168) Google and the of these adaptor/effector proteins for the RANK cytoplasmic We have shown that of the known TRAF can RANK cytoplasmic the largest of TRAF proteins known to any TNFR family member and suggesting that RANK may a of to RANK two TRAF binding amino binding of multiple TRAFs (TRAFs 1, 2, 3, 5, and and TRAF6 We specific of the RANK in to RANK for TRAF binding in within selective binding determinants for this significantly TRAFs 1, 2, and binding to RANK or TRAF6 The of these two in RANK is to TRAF binding in Y. S. 1997; PubMed Scopus Google Scholar) and Cell. Biol. 1998; PubMed Google Scholar). However, and of TRAF binding appears to be by sequences this shows that TRAF6 to RANK within amino of amino in a of TRAF6 binding but direct binding of TRAF6 to this of RANK was not Since of within this amino not TRAF6 TRAF6 to two sites and of other TRAF proteins or within the can affect TRAF6 binding to the are to these We have demonstrated that RANK of both the NF-κB and JNK pathways cytoplasmic necessary for TRAF The of the binding of TRAFs 1, 2, 3, 5, and in a of RANK NF-κB and JNK activity and NF-κB or JNK activity was the TRAF6 binding was RANKL of RANK cells induced NF-κB activation to to RANK suggesting that the to in the of direct binding of other RANK Although identified a with homology to other within the important for RANK signal transduction, were to the specific binding site for TRAF6 by mutagenesis not to the that TRAF6 binding is for RANK-mediated NF-κB and JNK activation, an of amino The of this in of NF-κB activation, while JNK activation was inhibited to a two of RANK and can JNK by of the TRAF binding to of these These also that for activation of TRAF6 is functionally with other TRAFs and binding Since are necessary for NF-κB signaling by RANK in this cell TRAF6 binding and to the downstream proteins plays a role in this to and TRAF6 has been shown to of both NF-κB and JNK pathways Goeddel D.V. M. Proc. Natl. Acad. Sci. U. S. A. 1997; PubMed Scopus Google these after RANK activation, TRAF6 may to distinct downstream proteins from those activated by or The of TRAF6 to functionally NF-κB signaling in RANK is of its role in CD40 signaling T. Mizushima S. Azuma S. Kobayashi N. Tojo T. Suzuki K. Aizawa S. Watanabe T. Mosialos G. Kieff E. T. J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). to CD40 TRAF6 a distinct domain of other TRAF interactions and can NF-κB signaling in the of direct or The NH2-terminal of TRAF6 only while the NH2-terminal of TRAFs and from both RANKL and RANK of TRAF6 in RANK and also suggests that may be in TNFR family signaling from the interaction of ligand and the signal from has for the signaling mechanisms of the protein a receptor by in the U. R. M. G. R. D. J. 1997; PubMed Scopus Google Scholar) and TRAF proteins for the activation of NF-κB G. M. R. T. C. Kieff E. Cell. 1995; Full Text PDF PubMed Scopus Google Scholar, E. Kieff E. Mosialos G. Cell. Biol. PubMed Google Scholar, R. Kieff E. Mosialos G. Proc. Natl. Acad. Sci. U. S. A. 93: PubMed Scopus Google Scholar, M. B. J. 1997; PubMed Google Scholar) and other pathways Mosialos G. Kieff E. N. J. 1997; PubMed Google Scholar). Although it is not RANK may signaling mechanisms activation or differentiation of RANK-expressing cells, show here that the functional of TRAF binding to RANK appears to be the downstream regulation of multiple activation The activation of nuclear transcription factors NF-κB and an role to and expression. While these a role for TRAF6 in RANK signal transduction, the of the TRAF6 binding sites to the role of TRAF6 binding in signaling events. The of RANK of binding of the different TRAFs in the of cellular activation or differentiation be important to and RANK signaling While this was B.G. V. J. Aggarwal B. J. Biol. Chem. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar) also described the of RANK with TRAFs 2, 5, and In contrast to these not TRAF6 binding to RANK of discrepancy may be by the of RANK from transfected cells B.G. V. J. Aggarwal B. J. Biol. Chem. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar), may have cytoplasmic proteins of with in the expressed RANK cytoplasmic domain and in vitro show the direct of TRAF6 with RANK In B.G. V. J. Aggarwal B. J. Biol. Chem. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar) not a role for of RANK in NF-κB activation, while demonstrate here a role of in NF-κB activation in to receptor and RANKL-mediated activation two assay The for this discrepancy are not and may be to in the We for cell for the and for and for the and for and for
Galibert et al. (Tue,) studied this question.
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