Tapasin is a MHC class I antigen processing molecule present in the lumen of the endoplasmic reticulum. It plays an important role in the maturation of MHC class I molecules in the ER lumen. This protein is one component of the peptide loading complex, and can be found associated with MHC class I molecules after the MHC class I heavy chain has associated with the Beta₂ microglobulin. Tapasin recruits MHC class I molecules to the TAP peptide transporter, and also enhances loading of MHC class I with high affinity peptides. Following loading of MHC class I with a high affinity ligand the interaction between tapasin and MHC class I disappears.^[1]

References

1. ^ Zhang, Y, Williams, DB. 2006. Assembly of MHC class I molecules within the endoplasmic reticulum. Immunol res. 35(1-2):151-62.

See also

• Transporter associated with antigen processing ("TAP")

External links

• MeSH tapasin