CD79a molecule, immunoglobulin-associated alpha, also known as mb-1, is a human gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

The mb-1 gene codes for a phosphoprotein

Phosphoprotein

Phosphoproteins are proteins that are physically bonded to a substance containing phosphoric acid . This category of organic molecules includes Fc receptors, Ulks, Calcineurins, K chips, and urocortins....

, designated CD79a (cluster of differentiation [CD]79a, that, together with the related CD79b

CD79B

CD79b molecule, immunoglobulin-associated beta, also known as CD79B , is a human gene.It is associated with agammaglobulinemia-6.-External links:...

 protein, forms a dimer

Dimer

A dimer is a chemical entity consisting of two structurally similar subunits called monomers joined by bonds that can be either strong or weak.- Organic chemistry :...

 associated with membrane-bound immunoglobulin in B-cells. The CD79a/CD79b dimer is closely associated with the B-cell antigen receptor, in a similar manner to the association of CD3

CD3

CD3 or CD-3 may be:* CD3 , an antigen, cluster of differentiation protein , part of the T cell receptor complex on a mature T lymphocyte* Ford CD3 platform* MediaMax CD-3, copy protection scheme* MiniCD, a 3-inch CD...

 with the T-cell receptor, and enables the cell to respond to the presence of antigen

Antigen

An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

s on its surface.

It is associated with agammaglobulinemia-3.

Interactions

CD79A has been shown to interact

Protein-protein interaction

Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with B-cell linker

B-cell linker

The B-cell linker protein is encoded by the BLNK gene and is an adaptor protein also known as SLP-65, BASH, and BCA. BLNK is expressed in B cells and macrophages and plays a large role in B cell receptor signalling, in a fashion analogous to the role its paralogue SLP-76 plays in T cell receptor...

 and Alpha-1-microglobulin/bikunin precursor.

Diagnostic relevance

The CD79a protein is present on the surface of B-cells throughout their life cycle, and is absent on all other healthy cells, making it a highly reliable marker for B-cells in immunohistochemistry

Immunohistochemistry

Immunohistochemistry or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...

. The protein remains present when B-cells transform into active plasma cell

Plasma cell

Plasma cells, also called plasma B cells, plasmocytes, and effector B cells, are white blood cells which produce large volumes of antibodies. They are transported by the blood plasma and the lymphatic system...

s, and is also present in virtually all B-cell neoplasms, including B-cell lymphoma

Lymphoma

Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...

s, plasmacytoma

Plasmacytoma

Plasmacytoma refers to a malignant plasma cell tumor growing within soft tissue or within the skeleton. The skeletal forms usually have other occult tumors and frequently disseminate to multiple myeloma over the course of 5–10 years. The soft tissue forms most often occur in the upper respiratory...

s, and myelomas. It is also present in abnormal lymphocytes associated with some cases of Hodgkins disease. Because even on B-cell precursors, it can be used to stain a wider range of cells than can the alternative B-cell marker CD20

CD20

B-lymphocyte antigen CD20 or CD20 is an activated-glycosylated phosphoprotein expressed on the surface of all B-cells beginning at the pro-B phase and progressively increasing in concentration until maturity....

, but the latter is more commonly retained on mature B-cell lymphomas, so that the two are often used together in immunohistochemistry panels.

External links