The crystal structure of CHIR-AB1: a primordial avian classical Fc receptor.
CHIR-AB1 is a newly identified avian immunoglobulin (Ig) receptor that includes both activating and inhibitory motifs and was therefore classified as a potentially bifunctional receptor. Recently, CHIR-AB1 was shown to bind the Fc region of chicken IgY and to induce calcium mobilization via associat...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2008
|
| _version_ | 1826278702588100608 |
|---|---|
| author | Arnon, T Kaiser, J West, A Olson, R Diskin, R Viertlboeck, B Göbel, T Bjorkman, P |
| author_facet | Arnon, T Kaiser, J West, A Olson, R Diskin, R Viertlboeck, B Göbel, T Bjorkman, P |
| author_sort | Arnon, T |
| collection | OXFORD |
| description | CHIR-AB1 is a newly identified avian immunoglobulin (Ig) receptor that includes both activating and inhibitory motifs and was therefore classified as a potentially bifunctional receptor. Recently, CHIR-AB1 was shown to bind the Fc region of chicken IgY and to induce calcium mobilization via association with the common gamma-chain, a subunit that transmits signals upon ligation of many different immunoreceptors. Here we describe the 1.8-A-resolution crystal structure of the CHIR-AB1 ectodomain. The receptor ectodomain consists of a single C2-type Ig domain resembling the Ig-like domains found in mammalian Fc receptors such as FcgammaRs and FcalphaRI. Unlike these receptors and other monomeric Ig superfamily members, CHIR-AB1 crystallized as a 2-fold symmetrical homodimer that bears no resemblance to variable or constant region dimers in an antibody. Analytical ultracentrifugation demonstrated that CHIR-AB1 exists as a mixture of monomers and dimers in solution, and equilibrium gel filtration revealed a 2:1 receptor/ligand binding stoichiometry. Measurement of the 1:1 CHIR-AB1/IgY interaction affinity indicates a relatively low affinity complex, but a 2:1 CHIR-AB1/IgY interaction allows an increase in apparent affinity due to avidity effects when the receptor is tethered to a surface. Taken together, these results add to the structural understanding of Fc receptors and their functional mechanisms. |
| first_indexed | 2024-03-06T23:47:54Z |
| format | Journal article |
| id | oxford-uuid:7193d359-09cb-4f44-a9ce-256fe4f781e2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:47:54Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | oxford-uuid:7193d359-09cb-4f44-a9ce-256fe4f781e22022-03-26T19:44:35ZThe crystal structure of CHIR-AB1: a primordial avian classical Fc receptor.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:7193d359-09cb-4f44-a9ce-256fe4f781e2EnglishSymplectic Elements at Oxford2008Arnon, TKaiser, JWest, AOlson, RDiskin, RViertlboeck, BGöbel, TBjorkman, PCHIR-AB1 is a newly identified avian immunoglobulin (Ig) receptor that includes both activating and inhibitory motifs and was therefore classified as a potentially bifunctional receptor. Recently, CHIR-AB1 was shown to bind the Fc region of chicken IgY and to induce calcium mobilization via association with the common gamma-chain, a subunit that transmits signals upon ligation of many different immunoreceptors. Here we describe the 1.8-A-resolution crystal structure of the CHIR-AB1 ectodomain. The receptor ectodomain consists of a single C2-type Ig domain resembling the Ig-like domains found in mammalian Fc receptors such as FcgammaRs and FcalphaRI. Unlike these receptors and other monomeric Ig superfamily members, CHIR-AB1 crystallized as a 2-fold symmetrical homodimer that bears no resemblance to variable or constant region dimers in an antibody. Analytical ultracentrifugation demonstrated that CHIR-AB1 exists as a mixture of monomers and dimers in solution, and equilibrium gel filtration revealed a 2:1 receptor/ligand binding stoichiometry. Measurement of the 1:1 CHIR-AB1/IgY interaction affinity indicates a relatively low affinity complex, but a 2:1 CHIR-AB1/IgY interaction allows an increase in apparent affinity due to avidity effects when the receptor is tethered to a surface. Taken together, these results add to the structural understanding of Fc receptors and their functional mechanisms. |
| spellingShingle | Arnon, T Kaiser, J West, A Olson, R Diskin, R Viertlboeck, B Göbel, T Bjorkman, P The crystal structure of CHIR-AB1: a primordial avian classical Fc receptor. |
| title | The crystal structure of CHIR-AB1: a primordial avian classical Fc receptor. |
| title_full | The crystal structure of CHIR-AB1: a primordial avian classical Fc receptor. |
| title_fullStr | The crystal structure of CHIR-AB1: a primordial avian classical Fc receptor. |
| title_full_unstemmed | The crystal structure of CHIR-AB1: a primordial avian classical Fc receptor. |
| title_short | The crystal structure of CHIR-AB1: a primordial avian classical Fc receptor. |
| title_sort | crystal structure of chir ab1 a primordial avian classical fc receptor |
| work_keys_str_mv | AT arnont thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT kaiserj thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT westa thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT olsonr thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT diskinr thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT viertlboeckb thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT gobelt thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT bjorkmanp thecrystalstructureofchirab1aprimordialavianclassicalfcreceptor AT arnont crystalstructureofchirab1aprimordialavianclassicalfcreceptor AT kaiserj crystalstructureofchirab1aprimordialavianclassicalfcreceptor AT westa crystalstructureofchirab1aprimordialavianclassicalfcreceptor AT olsonr crystalstructureofchirab1aprimordialavianclassicalfcreceptor AT diskinr crystalstructureofchirab1aprimordialavianclassicalfcreceptor AT viertlboeckb crystalstructureofchirab1aprimordialavianclassicalfcreceptor AT gobelt crystalstructureofchirab1aprimordialavianclassicalfcreceptor AT bjorkmanp crystalstructureofchirab1aprimordialavianclassicalfcreceptor |