MHC_class

Protein MHC_class_I*

Identifiers
HUGO:HLA-A HUGO:HLA-B HUGO:HLA-C HUGO:HLA-E HUGO:HLA-F HUGO:HLA-G HUGO:HLA-K HUGO:HLA-L

Maps_Modules
HMC:AVOIDING_IMMUNE_DESTRUCTION
Adaptive Immune Response / SMAC

References
PMID:16181333 PMID:22076556 PMID:10559964
DENDRITIC_CELL
CASCADE:IFNG
MHC class I molecules is heterodimers that consist of two polypeptide chains, ?? and ??2-microglobulin (b2m). The two chains are linked noncovalently via interaction of b2m and the ??3 domain. Only the ?? chain is polymorphic and encoded by a HLA gene, while the b2m subunit is not polymorphic and encoded by the Beta-2 microglobulin gene.
The MHC class I heavy chain, a transmembrane glycoprotein of approximately 44 kDa, binds upon synthesis to the membrane-associated endoplasmic reticulum (ER) chaperone, calnexin (CNX).
Upon dissociation from CNX, the heavy chain binds ??2 microglobulin (??2m) and is incorporated into the peptide-loading complex. The other constituents of the complex are the two subunits of the transporter associated with antigen processing (TAP1 and TAP2), the transmembrane glycoprotein tapasin, the soluble ER chaperone calreticulin (CRT), and the soluble thiol oxidoreductase ERp57. Peptides are transported into the ER from the cytosol via TAP, and, if necessary, they are trimmed by an ER-associated aminopeptidase (ERAAP or ERAP1) to 8???10 amino acids, the length that is generally required for association with class I molecules. If the peptide has the appropriate sequence, it binds to the MHC class I-??2m heterodimer, which is released from the peptide-loading complex. The fully assembled class I molecule then leaves the ER and travels via the Golgi apparatus to the plasma membrane, where it is accessible to CD8+ T cells.

Modifications:
In compartment: Endoplasmic Reticulum_Membrane

MHC_class_I*@Endoplasmic Reticulum_Membrane
MHC_class_I*@Endoplasmic Reticulum_Membrane

In compartment: INNATE_IMMUNE_CELL_Cytosol

MHC_class_I*@INNATE_IMMUNE_CELL_Cytosol

Participates in complexes:
In compartment: Endoplasmic Reticulum_Membrane

In compartment: INNATE_IMMUNE_CELL_Membrane

B2M:MHC_class_I*:Tumor_antigen_fragment@INNATE_IMMUNE_CELL_Membrane

In compartment: PHAGOSOME/ENDOSOME/LYSOSOME_Membrane

Participates in reactions:
As Reactant or Product:

As Catalyser: