The N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor.
We recently found that leukocytes from thrombospondin-1 (TSP1)-deficient mice exhibit significant reductions in cell surface CD44 relative to those from wild type mice. Because TSG-6 modulates CD44-mediated cellular interactions with hyaluronan, we examined the possibility that TSP1 interacts with T...
| Main Authors: | , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2005
|
| _version_ | 1797065211777122304 |
|---|---|
| author | Kuznetsova, SA Day, A Mahoney, D Rugg, MS Mosher, D Roberts, D |
| author_facet | Kuznetsova, SA Day, A Mahoney, D Rugg, MS Mosher, D Roberts, D |
| author_sort | Kuznetsova, SA |
| collection | OXFORD |
| description | We recently found that leukocytes from thrombospondin-1 (TSP1)-deficient mice exhibit significant reductions in cell surface CD44 relative to those from wild type mice. Because TSG-6 modulates CD44-mediated cellular interactions with hyaluronan, we examined the possibility that TSP1 interacts with TSG-6. We showed that recombinant full-length human TSG-6 (TSG-6Q) and the Link module of TSG-6 (Link_TSG6) bind 125I-TSP1 with comparable affinities. Trimeric recombinant constructs containing the N-modules of TSP1 or TSP2 inhibit binding of TSP1 to TSG-6Q and Link_TSG6, but other recombinant regions of TSP1 do not. Therefore, the N-modules of both TSP1 and TSP2 specifically recognize the Link module of TSG-6. Heparin, which binds to these domains of both proteins, strongly inhibits binding of TSP1 to Link_TSG6 and TSG-6Q, but hyaluronan does not. Inhibition by heparin results from its binding to TSP1, because heparin also inhibits TSP1 binding to Link_TSG6 mutants deficient in heparin binding. Removal of bound Ca2+ from TSP1 reduces its binding to full-length TSG-6. Binding of TSP1 to Link_TSG6, however, is enhanced by chelating divalent cations. In contrast, divalent cations do not influence binding of the N-terminal region of TSP1 to TSG-6Q. This implies that divalent cation dependence is due to conformational effects of calcium-binding to the C-terminal domains of TSP1. TSP1 enhances covalent modification of the inter-alpha-trypsin inhibitor by TSG-6 and transfer of its heavy chains to hyaluronan, suggesting a physiological function of TSP1 binding to TSG-6 in regulation of hyaluronan metabolism at sites of inflammation. |
| first_indexed | 2024-03-06T21:25:25Z |
| format | Journal article |
| id | oxford-uuid:42f03434-b838-43a3-9d55-1e3923d7852a |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T21:25:25Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:42f03434-b838-43a3-9d55-1e3923d7852a2022-03-26T14:52:18ZThe N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:42f03434-b838-43a3-9d55-1e3923d7852aEnglishSymplectic Elements at Oxford2005Kuznetsova, SADay, AMahoney, DRugg, MSMosher, DRoberts, DWe recently found that leukocytes from thrombospondin-1 (TSP1)-deficient mice exhibit significant reductions in cell surface CD44 relative to those from wild type mice. Because TSG-6 modulates CD44-mediated cellular interactions with hyaluronan, we examined the possibility that TSP1 interacts with TSG-6. We showed that recombinant full-length human TSG-6 (TSG-6Q) and the Link module of TSG-6 (Link_TSG6) bind 125I-TSP1 with comparable affinities. Trimeric recombinant constructs containing the N-modules of TSP1 or TSP2 inhibit binding of TSP1 to TSG-6Q and Link_TSG6, but other recombinant regions of TSP1 do not. Therefore, the N-modules of both TSP1 and TSP2 specifically recognize the Link module of TSG-6. Heparin, which binds to these domains of both proteins, strongly inhibits binding of TSP1 to Link_TSG6 and TSG-6Q, but hyaluronan does not. Inhibition by heparin results from its binding to TSP1, because heparin also inhibits TSP1 binding to Link_TSG6 mutants deficient in heparin binding. Removal of bound Ca2+ from TSP1 reduces its binding to full-length TSG-6. Binding of TSP1 to Link_TSG6, however, is enhanced by chelating divalent cations. In contrast, divalent cations do not influence binding of the N-terminal region of TSP1 to TSG-6Q. This implies that divalent cation dependence is due to conformational effects of calcium-binding to the C-terminal domains of TSP1. TSP1 enhances covalent modification of the inter-alpha-trypsin inhibitor by TSG-6 and transfer of its heavy chains to hyaluronan, suggesting a physiological function of TSP1 binding to TSG-6 in regulation of hyaluronan metabolism at sites of inflammation. |
| spellingShingle | Kuznetsova, SA Day, A Mahoney, D Rugg, MS Mosher, D Roberts, D The N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor. |
| title | The N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor. |
| title_full | The N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor. |
| title_fullStr | The N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor. |
| title_full_unstemmed | The N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor. |
| title_short | The N-terminal module of thrombospondin-1 interacts with the link domain of TSG-6 and enhances its covalent association with the heavy chains of inter-alpha-trypsin inhibitor. |
| title_sort | n terminal module of thrombospondin 1 interacts with the link domain of tsg 6 and enhances its covalent association with the heavy chains of inter alpha trypsin inhibitor |
| work_keys_str_mv | AT kuznetsovasa thenterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT daya thenterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT mahoneyd thenterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT ruggms thenterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT mosherd thenterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT robertsd thenterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT kuznetsovasa nterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT daya nterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT mahoneyd nterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT ruggms nterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT mosherd nterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor AT robertsd nterminalmoduleofthrombospondin1interactswiththelinkdomainoftsg6andenhancesitscovalentassociationwiththeheavychainsofinteralphatrypsininhibitor |