MHC class I polypeptide–related sequence A

MICA
Available structures
PDB	Ortholog search: PDBe RCSB
List of PDB id codes
	1B3J, 1HYR
Identifiers
Aliases	MICA, MIC-A, PERB11.1, MHC class I polypeptide-related sequence A, MHC class I chain–related protein A, MHC class I polypeptide–related protein A
External IDs	OMIM: 600169; MGI: 2179989; GeneCards: MICA; OMA:MICA - orthologs
Gene location (Human)
Chr.	Chromosome 6 (human)
End	31,415,315 bp
Gene location (Mouse)
Chr.	Chromosome 7 (mouse)
End	18,599,327 bp
RNA expression pattern
	Top expressed in
	Descending thoracic aorta; ; left ovary; ; popliteal artery; ; tibial arteries; ; body of uterus; ; ascending aorta; ; right uterine tube; ; stromal cell of endometrium; ; left coronary artery; ; right ovary;
	Top expressed in
	urinary bladder; ; uterus; ; lung; ; ovary; ; white adipose tissue; ; adrenal gland; ; zone of skin; ; esophagus; ; muscle tissue; ; skeletal muscle tissue;
	More reference expression data
	; ;
	More reference expression data
Gene ontology
Molecular function	beta-2-microglobulin binding; protein binding; natural killer cell lectin-like receptor binding;
Cellular component	cytoplasm; integral component of membrane; membrane; plasma membrane; integral component of plasma membrane; cell surface; extracellular space; external side of plasma membrane;
Biological process	cytolysis; adaptive immune response; negative regulation of natural killer cell activation; immune system process; gamma-delta T cell activation; response to heat; immune response to tumor cell; cellular response to DNA damage stimulus; defense response to bacterium; defense response to virus; regulation of immune response; negative regulation of natural killer cell mediated cytotoxicity; viral process; T cell mediated cytotoxicity; natural killer cell mediated cytotoxicity; immune response; natural killer cell activation; susceptibility to natural killer cell mediated cytotoxicity;
	Sources:Amigo / QuickGO
Orthologs
	100507436
	243864
ENSG00000231225; ENSG00000235233; ENSG00000204520; ENSG00000183214; ENSG00000233051;
	n/a
	ENSMUSG00000040987
	Q29983
	Q8HWE5
	NM_001289154; NM_000247; NM_001177519; NM_001289152; NM_001289153
	NM_153760; NM_153761
	NP_000238; NP_001170990; NP_001276081; NP_001276082; NP_001276083
	NP_715641; NP_715642
	Wikidata
View/Edit Human	View/Edit Mouse

MHC class I polypeptide–related sequence A (MICA) is a highly polymorphic cell surface glycoprotein encoded by the MICA gene located within MHC locus. MICA is related to MHC class I and it has similar domain structure, however, it is not associated with β2-microglobulin nor binds peptides as conventional MHC class I molecules do. MICA rather functions as a stress-induced ligand (as a danger signal) for integral membrane protein receptor NKG2D ("natural-killer group 2, member D"). MICA is broadly recognized by NK cells, γδ T cells, and CD8⁺ αβ T cells which carry NKG2D receptor on their cell surface and which are activated via this interaction.