MICB

This gene encodes a heavily glycosylated protein which is a ligand for the NKG2D type II receptor. Binding of the ligand activates the cytolytic response of natural killer (NK) cells, CD8 alphabeta T cells, and gammadelta T cells which express the receptor. This protein is stress-induced and is similar to MHC class I molecules; however, it does not associate with beta-2-microglobulin or bind peptides. Alternative splicing results in multiple transcript variants.

Full Name

MHC CLASS I POLYPEPTIDE-RELATED SEQUENCE B

Function

Seems to have no role in antigen presentation. Acts as a stress-induced self-antigen that is recognized by gamma delta T cells. Ligand for the KLRK1/NKG2D receptor. Binding to KLRK1 leads to cell lysis.

Biological Process

Adaptive immune response Source: UniProtKB-KW
Cytolysis Source: UniProtKB-KW
Gamma-delta T cell activation Source: UniProtKB
Immune response-activating cell surface receptor signaling pathway Source: UniProtKB
Negative regulation of defense response to virus by host Source: UniProtKB
Response to heat Source: UniProtKB
Response to oxidative stress Source: UniProtKB
Response to retinoic acid Source: UniProtKB

Cellular Location

Plasma membrane
Cell membrane
Note: Binding to human cytomegalovirus glycoprotein UL16 causes sequestration in the endoplasmic reticulum.

Involvement in disease

Rheumatoid arthritis (RA):
An inflammatory disease with autoimmune features and a complex genetic component. It primarily affects the joints and is characterized by inflammatory changes in the synovial membranes and articular structures, widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, and by atrophy and rarefaction of bony structures.

Topology

Extracellular: 23-309
Helical: 310-330
Cytoplasmic: 331-383

PTM

Proteolytically cleaved and released from the cell surface of tumor cells.