Figure 9.

Working model showing MHC I regulation by SMAR1. (Left) Endogenous SMAR1 interacts with HDAC1 and GATA2 thereby forming a repressor complex resulting in decreased calnexin expression. This decrease in calnexin expression as well as increased ERAP1 expression leads to increased MHC I expression. (Right) During low SMAR1 condition, GATA2 remains in acetylated condition and increases calnexin expression resulting in sequestration of MHC I heavy chain. This leads to low surface expression and antigen presentation.