UNC5H1 Induces Apoptosis via Its Juxtamembrane Region through an Interaction with NRAGE

Abstract

The UNC5Hs are axon guidance receptors that mediate netrin-1-dependent chemorepulsion, and dependence receptors that mediate netrin-1-independent apoptosis. Here, we report an interaction between UNC5H1 and NRAGE. Our experiments show that this interaction is responsible for apoptosis induced by UNC5H1, and this level of apoptosis is greater than the amount induced by either UNC5H2 or UNC5H3. We mapped the NRAGE binding domain of UNC5H1 to its ZU-5 domain and show that this region, in addition to an adjacent PEST sequence, is required for UNC5H1-mediated apoptosis. Chimeric UNC5H2 and UNC5H3 receptors, containing the NRAGE binding domain and PEST sequence of UNC5H1, bind NRAGE and cause increased levels of apoptosis. UNC5H1 expression does not induce apoptosis in differentiated PC12 cells, which down-regulate NRAGE, but induces apoptosis in native PC12 cells that endogenously express high levels of NRAGE and in differentiated PC12 cells when NRAGE is overexpressed. Together, these results demonstrate a mechanism for UNC5H1-mediated apoptosis that requires an interaction with the MAGE protein NRAGE. The UNC5Hs are axon guidance receptors that mediate netrin-1-dependent chemorepulsion, and dependence receptors that mediate netrin-1-independent apoptosis. Here, we report an interaction between UNC5H1 and NRAGE. Our experiments show that this interaction is responsible for apoptosis induced by UNC5H1, and this level of apoptosis is greater than the amount induced by either UNC5H2 or UNC5H3. We mapped the NRAGE binding domain of UNC5H1 to its ZU-5 domain and show that this region, in addition to an adjacent PEST sequence, is required for UNC5H1-mediated apoptosis. Chimeric UNC5H2 and UNC5H3 receptors, containing the NRAGE binding domain and PEST sequence of UNC5H1, bind NRAGE and cause increased levels of apoptosis. UNC5H1 expression does not induce apoptosis in differentiated PC12 cells, which down-regulate NRAGE, but induces apoptosis in native PC12 cells that endogenously express high levels of NRAGE and in differentiated PC12 cells when NRAGE is overexpressed. Together, these results demonstrate a mechanism for UNC5H1-mediated apoptosis that requires an interaction with the MAGE protein NRAGE. hemagglutinin nerve growth factor phosphate-buffered saline glutathione S-transferase analysis of variance green fluorescent protein Tdt-mediated dUTP nick-end labeling deleted in colorectal cancer paraformaldehyde Apoptosis plays a critical role in determining the size and shape of the vertebrate nervous system (1Nijhawan D. Honarpour N. Wang X. Annu. Rev. Neurosci. 2000; 23: 73-87Crossref PubMed Scopus (270) Google Scholar). The execution phase of the apoptotic program in neurons is well characterized and, as with most cell types, depends on the activation of intracellular proteases, primarily caspases (2Yuan J. Yankner B.A. Nature. 2000; 407: 802-809Crossref PubMed Scopus (1627) Google Scholar). In contrast, it is not well understood how cues from the environment regulate this process during development of the nervous system. UNC-5 was originally characterized in Caenorhabditis elegans as a gene required for axonal repulsion in netrin/UNC-6 responsive neurons (3Hedgecock E.M. Culotti J.G. Hall D.H. Neuron. 1990; 4: 61-85Abstract Full Text PDF PubMed Scopus (745) Google Scholar, 4Leung-Hagesteijn C. Spence A.M. Stern B.D. Zhou Y. Su M.W. Hedgecock E.M. Culotti J.G. Cell. 1992; 71: 289-299Abstract Full Text PDF PubMed Scopus (349) Google Scholar). The vertebrate members of this family (UNC5H1, 2, and 3) (5Ackerman S.L. Kozak L.P. Przyborski S.A. Rund L.A. Boyer B.B. Knowles B.B. Nature. 1997; 386: 838-842Crossref PubMed Scopus (323) Google Scholar, 6Leonardo E.D. Hinck L. Masu M. Keino-Masu K. Ackerman S.L. Tessier-Lavigne M. Nature. 1997; 386: 833-838Crossref PubMed Scopus (434) Google Scholar), together with C. elegans UNC-5 (4Leung-Hagesteijn C. Spence A.M. Stern B.D. Zhou Y. Su M.W. Hedgecock E.M. Culotti J.G. Cell. 1992; 71: 289-299Abstract Full Text PDF PubMed Scopus (349) Google Scholar) and Drosophila Unc5 (7Keleman K. Dickson B.J. Neuron. 2001; 32: 605-617Abstract Full Text Full Text PDF PubMed Scopus (251) Google Scholar), comprise a subgroup of the Ig superfamily of receptors. The UNC5s contain two Ig and two thrombospondin type-I repeats in the extracellular domain. In addition, their cytoplasmic domains contain regions of homology with other proteins: 1) a ZU-5 domain homologous to Zona Occludens-1, a protein implicated in tight-junction formation (8Schultz J. Milpetz F. Bork P. Ponting C.P. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 5857-5864Crossref PubMed Scopus (3055) Google Scholar); and 2) a C-terminal death domain, a domain first identified as the pro-apoptotic region of tumor necrosis factor receptor-1 (9Tartaglia L.A. Ayres T.M. Wong G.H. Goeddel D.V. Cell. 1993; 74: 845-853Abstract Full Text PDF PubMed Scopus (1173) Google Scholar, 10Hofmann K. Tschopp J. FEBS Lett. 1995; 371: 321-323Crossref PubMed Scopus (103) Google Scholar). In a netrin-1 gradient, a complex of UNC5H1 and DCC mediates repulsion (11Hong K. Hinck L. Nishiyama M. Poo M.M. Tessier-Lavigne M. Stein E. Cell. 1999; 97: 927-941Abstract Full Text Full Text PDF PubMed Scopus (584) Google Scholar), although there is evidence suggesting that short range repulsion by netrin-1 may be mediated by UNC5 alone (3Hedgecock E.M. Culotti J.G. Hall D.H. Neuron. 1990; 4: 61-85Abstract Full Text PDF PubMed Scopus (745) Google Scholar, 7Keleman K. Dickson B.J. Neuron. 2001; 32: 605-617Abstract Full Text Full Text PDF PubMed Scopus (251) Google Scholar). NRAGE (Dlxin-1, MAGE-D1) is a recently identified molecule belonging to the MAGE (melanoma antigen) protein family. There are currently over 25 MAGE proteins in humans, characterized by the presence of a MAGE homology domain. The expression of many MAGE proteins is restricted to cancer cells (12Barker P.A. Salehi A. J Neurosci. Res. 2002; 67: 705-712Crossref PubMed Scopus (269) Google Scholar); however, recent studies have revealed a role for two MAGE proteins in the nervous system. One MAGE family member, necdin, is thought to maintain the differentiated state of post-mitotic neurons by preventing entry into the cell cycle (13Taniura H. Taniguchi N. Hara M. Yoshikawa K. J. Biol. Chem. 1998; 273: 720-728Abstract Full Text Full Text PDF PubMed Scopus (149) Google Scholar, 14Hayashi Y. Matsuyama K. Takagi K. Sugiura H. Yoshikawa K. Biochem. Biophys. Res. Commun. 1995; 213: 317-324Crossref PubMed Scopus (79) Google Scholar). Another MAGE family member, NRAGE, is expressed in the nervous system during early development in proliferative neural populations (15Kendall S.E. Goldhawk D.E. Kubu C. Barker P.A. Verdi J.M. Mech. Dev. 2002; 117: 187-200Crossref PubMed Scopus (58) Google Scholar). Recent studies have reported two major functions for NRAGE, as a transcriptional regulator for the dlx/msx family of transcription factors (16Masuda Y. Sasaki A. Shibuya H. Ueno N. Ikeda K. Watanabe K. J. Biol. Chem. 2001; 276: 5331-5338Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar, 17Sasaki A. Masuda Y. Iwai K. Ikeda K. Watanabe K. J. Biol. Chem. 2002; 277: 22541-22546Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar) and as a regulator of apoptosis. The first study to implicate NRAGE in apoptosis found that NRAGE binds the nerve growth factor receptor p75NTR, blocks cell cycle progression, and promotes p75NTR-mediated apoptosis (18Salehi A.H. Roux P.P. Kubu C.J. Zeindler C. Bhakar A. Tannis L.L. Verdi J.M. Barker P.A. Neuron. 2000; 27: 279-288Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar). Subsequently, it was found to utilize two mechanisms to induce apoptosis in cells. One involves NRAGE-dependent degradation of the survival protein XIAP (X-linked inhibitor of apoptosis) (19Jordan B.W. Dinev D. LeMellay V. Troppmair J. Gotz R. Wixler L. Sendtner M. Ludwig S. Rapp U.R. J. Biol. Chem. 2001; 276: 39985-39989Abstract Full Text Full Text PDF PubMed Scopus (79) Google Scholar) and the other involves NRAGE-dependent activation of the c-Jun and caspases A.H. S. Barker P.A. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar). a role to for netrin-1 receptors in apoptosis. In this we report that UNC5H1 mediates than the amount of cell death as UNC5H2 and and we NRAGE as a binding for UNC5H1 binds and be from cells that endogenously express the apoptotic region and NRAGE binding domain of UNC5H1 to its region that a PEST sequence and ZU-5 domain. We that UNC5H2 and UNC5H3 proteins containing the PEST and ZU-5 sequence of UNC5H1 bind NRAGE and induce increased levels of apoptosis. UNC5H1 and NRAGE the cell in cells and are in regions of the nervous system. PC12 cells, we show that UNC5H1 expression induces apoptosis in cells that endogenously express high levels of NRAGE but not in differentiated cells that down-regulate NRAGE. We show that UNC5H1 induces apoptosis in these differentiated PC12 cells when NRAGE is together a mechanism for UNC5H1-mediated apoptosis that requires an interaction with NRAGE. into which a C-terminal as E.D. Hinck L. Masu M. Keino-Masu K. Ackerman S.L. Tessier-Lavigne M. Nature. 1997; 386: 833-838Crossref PubMed Scopus (434) Google Scholar, K. Hinck L. Nishiyama M. Poo M.M. Tessier-Lavigne M. Stein E. Cell. 1999; 97: 927-941Abstract Full Text Full Text PDF PubMed Scopus (584) Google Scholar). other in by the to and with the and to the region of UNC5H2 and UNC5H3 and this region was with a the apoptotic region of UNC5H1 was by with and into the in was with of the was into with a as (16Masuda Y. Sasaki A. Shibuya H. Ueno N. Ikeda K. Watanabe K. J. Biol. Chem. 2001; 276: 5331-5338Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar). and a Kozak and into the by cells in with and PC12 cells in with and PC12 and on differentiated for by in with UNC5H1 was in cells as by the and was to native and differentiated PC12 cells. for in for in and in for in was for by for was and on cells for and the of cells in in to for and a of cells for and apoptotic was and in a by The UNC5H1 was the extracellular domain of L. E. D. and M. The NRAGE was in (16Masuda Y. Sasaki A. Shibuya H. Ueno N. Ikeda K. Watanabe K. J. Biol. Chem. 2001; 276: 5331-5338Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar). and for and The was to the and into the in which a domain. was by into of with the binding domain (11Hong K. Hinck L. Nishiyama M. Poo M.M. Tessier-Lavigne M. Stein E. Cell. 1999; 97: 927-941Abstract Full Text Full Text PDF PubMed Scopus (584) Google Scholar). was into the with a gene and gene Cell. 1993; 74: Full Text PDF PubMed Scopus Google Scholar). for the to on with and for the to in was and with the in system In was in with of or to The for with binding and by for or PC12 cells as (11Hong K. Hinck L. Nishiyama M. Poo M.M. Tessier-Lavigne M. Stein E. Cell. 1999; 97: 927-941Abstract Full Text Full Text PDF PubMed Scopus (584) Google Scholar). cells in containing and The was for and in a for The was with to protein for of the intracellular domain was from into the and of into to was by in for with in and to and in with for in and in for was in for and with with for was for either UNC5H1 or NRAGE was to and in for and for by with in with for and was to protein levels analysis and on that the UNC5Hs may be in apoptotic (11Hong K. Hinck L. Nishiyama M. Poo M.M. Tessier-Lavigne M. Stein E. Cell. 1999; 97: 927-941Abstract Full Text Full Text PDF PubMed Scopus (584) Google Scholar, F. F. E. P. J. 2001; PubMed Scopus Google Scholar), we the of UNC5H1, and UNC5H3 to induce apoptosis in cells. Apoptosis was by to cells and labeling to a of apoptosis. The of is not by in the of cells are cell and of cells are was as a to the of death to and protein in cells. a of UNC5H1 cells that and of of cells. cell is with cells UNC5H2 and UNC5H3 that maintain cell and of cells of apoptotic that UNC5H1 expression a in apoptotic cells with the UNC5H2 and UNC5H3 induce apoptosis over cells for but levels than UNC5H1 expression induces the most apoptosis in we on the mechanism the of UNC5H1 to induce apoptosis. the mechanism by UNC5H1, a was on a from the intracellular domain of UNC5H1 as we identified as the C-terminal of the pro-apoptotic protein NRAGE (Dlxin-1, MAGE-D1) (16Masuda Y. Sasaki A. Shibuya H. Ueno N. Ikeda K. Watanabe K. J. Biol. Chem. 2001; 276: 5331-5338Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar, A.H. Roux P.P. Kubu C.J. Zeindler C. Bhakar A. Tannis L.L. Verdi J.M. Barker P.A. Neuron. 2000; 27: 279-288Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar). The NRAGE sequence a region of 25 repeats of a sequence by a MAGE homology domain. The and the of NRAGE and the MAGE domain, and the C-terminal The domains between UNC5H1 and NRAGE mapped in The C-terminal of NRAGE, the is required for binding the intracellular domain of UNC5H1 but is not to on its the the MAGE domain alone to with however, the C-terminal the MAGE domain binding the C-terminal of NRAGE may bind UNC5H1, or the is for the MAGE domain to the MAGE domain to bind we mapped the NRAGE binding of of from the the death domain, with C-terminal of UNC5H1 to we of and for the to with We found that the ZU-5 domain binding with and that this region is for the interaction between UNC5H1 and NRAGE. UNC5H1 a to induce apoptosis levels than either UNC5H2 or UNC5H3 we the system to the NRAGE interaction is to UNC5H1 or it with other in does not with either UNC5H2 or UNC5H3 and results that UNC5H1 with NRAGE its ZU-5 domain. that the interaction in is the of a we an in protein revealed a interaction with in alone that the interaction between UNC5H1 and NRAGE is we UNC5H1 with NRAGE in cells by cells with and that with when is and not when cells are with the death domain of UNC5H1 does not the interaction with in cells, but the intracellular domain of UNC5H1 the interaction results in and the ZU-5 domain as the NRAGE binding domain. the of the interaction between NRAGE and UNC5H1 in cells, we or with Our results show that binds but levels than of NRAGE from that NRAGE than and interaction between and is we the of UNC5H1 and NRAGE in cells. studies have that NRAGE is to the and the cell (16Masuda Y. Sasaki A. Shibuya H. Ueno N. Ikeda K. Watanabe K. J. Biol. Chem. 2001; 276: 5331-5338Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar, A.H. Roux P.P. Kubu C.J. Zeindler C. Bhakar A. Tannis L.L. Verdi J.M. Barker P.A. Neuron. 2000; 27: 279-288Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar). UNC5H1 is a we NRAGE is to the in the presence of of and in cells between the two proteins the cell the interaction between UNC5H1 and NRAGE to be the two proteins be in the the is that are expressed in the nervous system E.D. Hinck L. Masu M. Keino-Masu K. Ackerman S.L. Tessier-Lavigne M. Nature. 1997; 386: 833-838Crossref PubMed Scopus (434) Google Scholar, S.E. Goldhawk D.E. Kubu C. Barker P.A. Verdi J.M. Mech. Dev. 2002; 117: 187-200Crossref PubMed Scopus (58) Google Y. Sasaki A. Shibuya H. Ueno N. Ikeda K. Watanabe K. J. Biol. Chem. 2001; 276: 5331-5338Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar, A.H. Roux P.P. Kubu C.J. Zeindler C. Bhakar A. Tannis L.L. Verdi J.M. Barker P.A. Neuron. 2000; 27: 279-288Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar, A. A. V. Cell. Biol. Res. Commun. 2001; 4: PubMed Scopus Google Scholar, C. S. Mech. Dev. 2001; PubMed Scopus Google Scholar). of we in analysis on from are found together in the and are from the and The of the the and the for and We have other of expression during the and and neurons not demonstrate that are in the nervous suggesting may together in The that UNC5H1 induces apoptosis was in cells. NRAGE is required for UNC5H1-mediated cells express NRAGE this we a on cell a NRAGE. that NRAGE to be in cell and we to a analysis on the of UNC5H1 to induce apoptosis in these cells. the interaction between UNC5H1 and NRAGE is required for cell we of UNC5H1 and these for the to induce apoptosis. we a that of the intracellular domain, and found that induces apoptosis than UNC5H1 this the NRAGE binding domain, it the death domain, a region of UNC5H1 by to be required for UNC5H1-mediated apoptosis F. F. E. P. J. 2001; PubMed Scopus Google Scholar). we a deleted in the death domain induces apoptosis. Our results show that does not the of UNC5H1 to induce death in cells we an UNC5H1 deleted in the DCC binding domain the UNC5H1 intracellular domain with the netrin-1 receptor DCC (11Hong K. Hinck L. Nishiyama M. Poo M.M. Tessier-Lavigne M. Stein E. Cell. 1999; 97: 927-941Abstract Full Text Full Text PDF PubMed Scopus (584) Google Scholar), which may be pro-apoptotic P. S. N. D.E. Nature. 1998; PubMed Scopus Google Scholar). One is that cell death induced by UNC5H1 is the of a Our results show that the DCC binding domain on the of UNC5H1 to induce apoptosis Together, these results that the binding domain is required for UNC5H1-mediated apoptosis and a role for the death and DCC binding We apoptosis induced UNC5H1 by the NRAGE binding however, we that apoptosis the level in cells we the intracellular domain of UNC5H1 to this the death that UNC5H1 apoptosis to analysis of this region between the of the domain and the of the ZU-5 domain revealed the presence of a PEST sequence that is not in either UNC5H2 or UNC5H3 M. Biochem. Sci. Full Text PDF PubMed Scopus Google Scholar, S. R. M. PubMed Scopus Google Scholar). we the PEST domain the UNC5H1 apoptotic is results that most of the UNC5H1 death requires the presence of the NRAGE binding domain however, requires the PEST sequence of we identified the region, of the adjacent PEST and ZU-5 as the region in UNC5H1-mediated apoptosis and NRAGE UNC5H1 expression induces the of apoptosis in cells UNC5H2 expression induces than and UNC5H3 expression induces The is for the UNC5Hs to with NRAGE. UNC5H1 binds NRAGE UNC5H2 binds NRAGE and UNC5H3 binding results that the of UNC5Hs to induce apoptosis depends on their interaction with NRAGE. we the apoptotic domain of UNC5H1, when on the homologous receptors, either the apoptotic or NRAGE we two receptors and in which the region the ZU-5 domain of UNC5H2 and UNC5H3 was with the region from UNC5H1 Our show that the the of apoptotic cells with UNC5H2 to levels to UNC5H1 The a but in the of apoptotic cells with UNC5H3 results that the apoptotic region of the PEST sequence and ZU-5 domain, is a pro-apoptotic to we receptors, and with the apoptotic domain of UNC5H1 the interaction domain with NRAGE, we that the receptors, which show an increased to induce cell show an for NRAGE. In of this and show increased NRAGE binding with their We that binds an of NRAGE than We that with NRAGE UNC5H3 does not show a interaction with NRAGE and induce a amount of the in death is for than for that UNC5H3 is from UNC5H1 and and factors other than the to bind NRAGE may UNC5H3 from apoptosis The experiments on receptors, which cause an in apoptosis and an in the to bind NRAGE over receptors, the that NRAGE binding UNC5H1-mediated apoptosis. UNC5H1 with NRAGE in cells, we PC12 cells, endogenously express proteins (18Salehi A.H. Roux P.P. Kubu C.J. Zeindler C. Bhakar A. Tannis L.L. Verdi J.M. Barker P.A. Neuron. 2000; 27: 279-288Abstract Full Text Full Text PDF PubMed Scopus (257) Google A. A. V. Cell. Biol. Res. Commun. 2001; 4: PubMed Scopus Google Scholar) E. and L. and be differentiated to UNC5H1 we characterized the of the we show that but not or we of native and differentiated PC12 cells with and with a NRAGE. that NRAGE with in native PC12 cells but not in differentiated PC12 cells. UNC5H1 and NRAGE when expressed levels in but not in differentiated PC12 cells. an on native and differentiated PC12 that NRAGE is of differentiated PC12 cells express NRAGE than native PC12 cells, and this may NRAGE is not with UNC5H1 in differentiated cells. NRAGE is in differentiated PC12 cells, we that UNC5H1 induce apoptosis in native PC12 cells, to cells, but not in differentiated PC12 cells. we PC12 cells with and apoptosis Tdt-mediated dUTP nick-end labeling The revealed a in the of apoptosis between UNC5H1 native and differentiated PC12 cells. of the native PC12 cells UNC5H1 with of native cells with as a and In contrast, of differentiated PC12 cells UNC5H1 are apoptotic and differentiated PC12 cells down-regulate NRAGE, we to in these cells. We found that expression of NRAGE alone in a level of although of NRAGE in differentiated cells not cause cell the cells to have their that induced In contrast, of NRAGE and UNC5H1 in a in the of cells experiments that NRAGE expression is required for UNC5H1 to induce an apoptotic the first evidence of an interaction between UNC5H1 and NRAGE. is the induced by of the UNC5Hs in either apoptosis or axon The of NRAGE as a binding for UNC5H1 the mechanism of UNC5H1-mediated studies have recently to on NRAGE Our analysis of the role UNC5Hs in apoptosis first revealed a between the of UNC5H1 to induce death with UNC5H2 or UNC5H3. UNC5H1 induces apoptosis than the level of greater than and greater than We found that UNC5H1 with NRAGE than UNC5H2 or UNC5H3. the of receptors, we show that of these apoptosis and NRAGE the region of The region of UNC5H1 of a short PEST sequence by a ZU-5 domain. In contrast, and C. elegans UNC-5 not contain a PEST sequence and have an of in the ZU-5 domain. sequence may the between the UNC5Hs to bind NRAGE and induce apoptosis. We that the UNC5H1 PEST sequence, is of apoptosis when the of the intracellular domain is PEST of in and have to in a of most in protein degradation by the M. Biochem. Sci. Full Text PDF PubMed Scopus Google Scholar, S. R. M. PubMed Scopus Google Scholar). is that the receptor a PEST sequence, and, UNC5H1, the PEST is the region K. M. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). region on p75NTR, to it from the death domain, is of apoptosis in cells K. M. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). UNC5H1 and their region for the interaction with NRAGE (18Salehi A.H. Roux P.P. Kubu C.J. Zeindler C. Bhakar A. Tannis L.L. Verdi J.M. Barker P.A. Neuron. 2000; 27: 279-288Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar). UNC5H1 and and it is that NRAGE induces apoptosis mechanisms for receptors. The of the region of UNC5H1 as a required for apoptotic and NRAGE binding was UNC5H1 a C-terminal death domain that to be required for apoptosis F. F. E. P. J. 2001; PubMed Scopus Google Scholar). domains their are responsible for apoptosis induced by the death receptors, tumor necrosis factor receptor-1 and (9Tartaglia L.A. Ayres T.M. Wong G.H. Goeddel D.V. Cell. 1993; 74: 845-853Abstract Full Text PDF PubMed Scopus (1173) Google Scholar, A. V. 1998; PubMed Scopus Google Scholar, D. Cell. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar). death domain containing proteins have of these proteins in to apoptosis and induce apoptosis of their death domain p75NTR, K. Tschopp J. FEBS Lett. 1995; 371: 321-323Crossref PubMed Scopus (103) Google Scholar, K. M. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar, K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar, E. A. D. M. E. Biochem. Sci. 1995; Full Text PDF PubMed Scopus Google Scholar, S. J. J. L.L. D.E. 1993; PubMed Scopus Google Scholar). it may be to of the death domain of UNC5H1 in as a interaction domain. studies show that NRAGE functions as a pro-apoptotic with to induce apoptosis (18Salehi A.H. Roux P.P. Kubu C.J. Zeindler C. Bhakar A. Tannis L.L. Verdi J.M. Barker P.A. Neuron. 2000; 27: 279-288Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar), and studies identified two mechanisms apoptosis. One is by the degradation of the survival protein XIAP of apoptosis) (19Jordan B.W. Dinev D. LeMellay V. Troppmair J. Gotz R. Wixler L. Sendtner M. Ludwig S. Rapp U.R. J. Biol. Chem. 2001; 276: 39985-39989Abstract Full Text Full Text PDF PubMed Scopus (79) Google Scholar), and the is by the c-Jun and of which are for cell death A.H. S. Barker P.A. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar). is not these two mechanisms in cell types, or NRAGE induce to the of the We that native PC12 cells, which express UNC5H1 and NRAGE, express high levels of XIAP not The presence of this protein may be native PC12 cells not apoptosis levels of UNC5H1 and NRAGE. In a the of UNC5H1 may a apoptotic NRAGE that or the XIAP survival to cell death in native PC12 cells. NRAGE transcription the dlx/msx family of transcription factors (16Masuda Y. Sasaki A. Shibuya H. Ueno N. Ikeda K. Watanabe K. J. Biol. Chem. 2001; 276: 5331-5338Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar, 17Sasaki A. Masuda Y. Iwai K. Ikeda K. Watanabe K. J. Biol. Chem. 2002; 277: 22541-22546Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar). NRAGE protein be found in the and an interaction with transcriptional NRAGE is with UNC5H1, however, it is primarily found the cell from transcription factors in the we that UNC5H1 a by to the intracellular domain into the not of UNC5H1 may a for an complex to with transcriptional NRAGE is primarily expressed in proliferative neural and not in differentiated neurons (15Kendall S.E. Goldhawk D.E. Kubu C. Barker P.A. Verdi J.M. Mech. Dev. 2002; 117: 187-200Crossref PubMed Scopus (58) Google Scholar). we show that NRAGE expression is high in native PC12 cells but in differentiated PC12 cells. in NRAGE expression UNC5H1 alone does not induce apoptosis in differentiated We show the for NRAGE in UNC5H1-mediated apoptosis by NRAGE with UNC5H1 in these cells and induce apoptosis. to many neural are and for survival in development are by apoptosis to that cell are Apoptosis in to survival cues may a as UNC5H1, and the presence of NRAGE to the death a cell to studies have that neurons UNC5Hs to mediate axon guidance or cell (3Hedgecock E.M. Culotti J.G. Hall D.H. Neuron. 1990; 4: 61-85Abstract Full Text PDF PubMed Scopus (745) Google Scholar, 7Keleman K. Dickson B.J. Neuron. 2001; 32: 605-617Abstract Full Text Full Text PDF PubMed Scopus (251) Google Scholar, K. Hinck L. Nishiyama M. Poo M.M. Tessier-Lavigne M. Stein E. Cell. 1999; 97: 927-941Abstract Full Text Full Text PDF PubMed Scopus (584) Google Scholar, K. Przyborski S.A. Ackerman S.L. J. Neurosci. 2002; PubMed Google Scholar, S.A. Knowles B.B. Ackerman S.L. 1998; Google Scholar). of NRAGE that a differentiated to guidance cues is to an apoptotic The that UNC5Hs induce apoptosis was in the of We for