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Effect of a tapasin mutant on the assembly of the mouse MHC class I molecule H2‐K d
Author(s) -
Simone Laura C,
Wang Xiaojian,
Tuli Amit,
Solheim Joyce C
Publication year - 2010
Publication title -
immunology and cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0818-9641
DOI - 10.1038/icb.2009.59
Subject(s) - mhc class i , major histocompatibility complex , chemistry , microbiology and biotechnology , cysteine , mutant , biochemistry , biology , enzyme , gene
Major histocompatibility complex (MHC) class I heavy chain/β 2 m heterodimers assemble with antigenic peptides through interactions with peptide‐loading complex proteins, including tapasin and ERp57. In human cells, a cysteine residue within tapasin (C95) has been shown to form a covalent bond with ERp57. In this study, we focused on the effect of this tapasin amino‐acid residue in mouse cells expressing the MHC class I molecule H2‐K d . We showed that a large disulfide‐bonded complex was present in the mouse cells that included ERp57, tapasin, and K d . Furthermore, in mouse cells, unlike human cells, we found that tapasin mutated at C95 can participate in a non‐covalent complex with ERp57. Comparison of our findings to earlier findings with a human molecule (HLA‐B ∗ 4402) also revealed that a tapasin C95 mutation has a stronger effect on the maturation and stability of K d than HLA‐B ∗ 4402. Overall, our results characterize the influence of this tapasin cysteine residue on the stable surface expression of a mouse MHC class I molecule and reveal differences in tapasin C95 interactions and effects between mouse and human systems.