Inhibition of host tapasin by virus

Tapasin is a type I transmembrane protein essential for the optimal expression of stable MHC class I molecules on host cell surface. Its helps the MHC class I molecules to remain in a peptide receptive state, avoiding irresversible denaturation.

us3 e3-k19

HCMV encodes a protein termed US3 that directly binds and inhibits Tapasin. US3 is also a transmembrane protein and the interaction with host tapasin occurs through their endoplasmic reticulum domain. The E3-19K protein from adenovirus also inhibit the pathway, by preventing association of Tapasin with TAP.