HLA-A
HLA-A (major histocompatibility complex, class I, A) encodes the heavy chain of an MHC class I molecule that presents peptides to cytotoxic T cells. It pairs with beta-2 microglobulin and is expressed in nearly all cells. Browse Assay Genie's current range of HLA-A research reagents below, or read on for the biology behind the target.
HLA-A is a member of the HLA class I heavy chain paralogues. The mature class I molecule is a heterodimer of a membrane-anchored heavy chain and a light chain, beta-2 microglobulin. Class I molecules play a central role in the immune system by presenting peptides derived from the endoplasmic reticulum lumen so that cytotoxic T cells can recognise them. UniProt places the protein at the cell membrane and the endoplasmic reticulum membrane, and the HLA-A protein belongs to the MHC class I family.
The HLA-A gene contains 8 exons. Exon 1 encodes the leader peptide, exons 2 and 3 encode the alpha1 and alpha2 domains, which both bind the peptide, exon 4 encodes the alpha3 domain, exon 5 encodes the transmembrane region, and exons 6 and 7 encode the cytoplasmic tail. The heavy chain is approximately 45 kDa. Polymorphisms within exons 2 and 3 determine the peptide-binding specificity of each class I molecule, and more than 6000 HLA-A alleles have been described. Typing for these polymorphisms is routinely performed for bone marrow and kidney transplantation.
The HLA system influences the occurrence and outcome of infectious diseases, including those caused by the malaria parasite, human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus (SARS-CoV). As an example from UniProt, allele A*74:01 presents immunodominant HIV-1 epitopes from gag-pol and rev and may contribute to viral load control in chronic HIV-1 infection. The spike and nucleocapsid proteins of SARS-CoV-2 are reported to contain multiple class I epitopes with predicted HLA restrictions, and individual HLA variation may help explain differing immune responses to a virus across a population.
HLA-A presents peptides derived from the endoplasmic reticulum lumen to cytotoxic T cells, making it a central subject in studies of class I antigen processing.
Polymorphisms in exons 2 and 3 set peptide-binding specificity, and HLA-A typing is routinely performed for bone marrow and kidney transplantation.
HLA-A alleles such as A*74:01 present immunodominant HIV-1 epitopes and may contribute to viral load control in chronic infection.
SARS-CoV-2 spike and nucleocapsid proteins are reported to contain class I epitopes with predicted HLA restrictions, relevant to population differences in immune response.
HLA-A encodes the heavy chain of an MHC class I molecule. Together with beta-2 microglobulin, it presents peptides derived from the endoplasmic reticulum lumen at the cell surface so that cytotoxic T cells can recognise them. Class I molecules are expressed in nearly all cells.
HLA-A stands for major histocompatibility complex, class I, A; the UniProt name is HLA class I histocompatibility antigen, A alpha chain. More than 6000 alleles have been described, and polymorphisms in exons 2 and 3 determine each molecule's peptide-binding specificity.
The HLA system affects the occurrence and outcome of infections including malaria, HIV and SARS-CoV. Allele A*74:01 presents immunodominant HIV-1 epitopes and may help control viral load in chronic infection. Check the datasheet of any product for its validated reactivity.
Other HLA class I and class II genes involved in antigen presentation and immune recognition.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P04439; product specifications from Assay Genie datasheets.