Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain.
Class II molecules of the major histocompatibility complex (MHC) are composed of two polymorphic glycoprotein chains (alpha and beta), that associate in the ER with a third, non-polymorphic glycoprotein known as the invariant chain (Ii). We have examined the relationship between the intracellular tr...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Jezik: | English |
| Izdano: |
1994
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| _version_ | 1826283343850766336 |
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| author | Bonnerot, C Marks, MS Cosson, P Robertson, E Bikoff, E Germain, R Bonifacino, J |
| author_facet | Bonnerot, C Marks, MS Cosson, P Robertson, E Bikoff, E Germain, R Bonifacino, J |
| author_sort | Bonnerot, C |
| collection | OXFORD |
| description | Class II molecules of the major histocompatibility complex (MHC) are composed of two polymorphic glycoprotein chains (alpha and beta), that associate in the ER with a third, non-polymorphic glycoprotein known as the invariant chain (Ii). We have examined the relationship between the intracellular transport and physico-chemical characteristics of various combinations of murine alpha, beta and Ii chains. Biochemical and morphological analyses of transfected fibroblasts expressing class II MHC chains show that both unassembled alpha and beta chains, as well as a large fraction of alpha+beta complexes synthesized in the absence of Ii chain, are retained in the ER in association with the immunoglobulin heavy chain binding protein, BiP. Analyses by sedimentation velocity on sucrose gradients show that most incompletely assembled class II MHC species exist as high molecular weight aggregates in both transfected fibroblasts and spleen cells from mice carrying a disruption of the Ii chain gene. This is in contrast to the sedimentation properties of alpha beta Ii complexes from normal mice, which migrate as discrete, stoichiometric complexes of M(r) approximately 200,000-300,000. These observations suggest that assembly with the Ii chain prevents accumulation of aggregated alpha and beta chains in the ER, which might relate to the known ability of the Ii chain to promote exit of class II MHC molecules from the ER. |
| first_indexed | 2024-03-07T00:57:29Z |
| format | Journal article |
| id | oxford-uuid:8894394f-b50e-4fd1-a701-d0ae8a59953f |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:57:29Z |
| publishDate | 1994 |
| record_format | dspace |
| spelling | oxford-uuid:8894394f-b50e-4fd1-a701-d0ae8a59953f2022-03-26T22:18:18ZAssociation with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:8894394f-b50e-4fd1-a701-d0ae8a59953fEnglishSymplectic Elements at Oxford1994Bonnerot, CMarks, MSCosson, PRobertson, EBikoff, EGermain, RBonifacino, JClass II molecules of the major histocompatibility complex (MHC) are composed of two polymorphic glycoprotein chains (alpha and beta), that associate in the ER with a third, non-polymorphic glycoprotein known as the invariant chain (Ii). We have examined the relationship between the intracellular transport and physico-chemical characteristics of various combinations of murine alpha, beta and Ii chains. Biochemical and morphological analyses of transfected fibroblasts expressing class II MHC chains show that both unassembled alpha and beta chains, as well as a large fraction of alpha+beta complexes synthesized in the absence of Ii chain, are retained in the ER in association with the immunoglobulin heavy chain binding protein, BiP. Analyses by sedimentation velocity on sucrose gradients show that most incompletely assembled class II MHC species exist as high molecular weight aggregates in both transfected fibroblasts and spleen cells from mice carrying a disruption of the Ii chain gene. This is in contrast to the sedimentation properties of alpha beta Ii complexes from normal mice, which migrate as discrete, stoichiometric complexes of M(r) approximately 200,000-300,000. These observations suggest that assembly with the Ii chain prevents accumulation of aggregated alpha and beta chains in the ER, which might relate to the known ability of the Ii chain to promote exit of class II MHC molecules from the ER. |
| spellingShingle | Bonnerot, C Marks, MS Cosson, P Robertson, E Bikoff, E Germain, R Bonifacino, J Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain. |
| title | Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain. |
| title_full | Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain. |
| title_fullStr | Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain. |
| title_full_unstemmed | Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain. |
| title_short | Association with BiP and aggregation of class II MHC molecules synthesized in the absence of invariant chain. |
| title_sort | association with bip and aggregation of class ii mhc molecules synthesized in the absence of invariant chain |
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