A role for calnexin (IP90) in the assembly of class II MHC molecules.
AUTOR(ES)
Anderson, K S
RESUMO
Major histocompatibility complex (MHC) class II antigens consist of alpha and beta chains that associate intracellularly with the invariant (I) chain. The HLA-DR alpha beta I complex assembles in the endoplasmic reticulum (ER) into a nonameric structure via progressive addition of three alpha beta dimers to a core invariant chain trimer. We have examined intracellular association of alpha beta I complexes with the resident ER protein calnexin. Calnexin associates rapidly (within 3 min) with newly synthesized alpha, beta and I chains, and remains associated with the assembling alpha beta I complex until the final alpha beta dimer is added, forming the complete nonamer. Dissociation of calnexin parallels egress of alpha beta I from the ER. These results suggest that calnexin retains and stabilizes both free class II subunits and partially assembled class II-I chain complexes until assembly of the nonamer is complete.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=394858Documentos Relacionados
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