Epstein-Barr virus induced gene 3, also known as EBI3, is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 which in humans is encoded by the EBI3 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...

.

Function

This gene was identified by the induction of its expression in B lymphocytes by Epstein-Barr virus

Epstein-Barr virus

The Epstein–Barr virus , also called human herpesvirus 4 , is a virus of the herpes family and is one of the most common viruses in humans. It is best known as the cause of infectious mononucleosis...

 infection. The protein encoded by this gene is a secreted glycoprotein

Glycoprotein

Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...

, which is a member of the hematopoietin receptor family related to the p40 subunit of interleukin 12 (IL-12

Interleukin 12

Interleukin 12 is an interleukin that is naturally produced by dendritic cells, macrophages and human B-lymphoblastoid cells in response to antigenic stimulation.-Gene and structure:...

). It plays a role in regulating cell-mediated immune responses.

EBI3 is a subunit in 2 distinct heterodimeric

Protein dimer

In biochemistry, a dimer is a macromolecular complex formed by two, usually non-covalently bound, macromolecules like proteins or nucleic acids...

 cytokine

Cytokine

Cytokines are small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system and are a category of signaling molecules used extensively in intercellular communication...

s: interleukin-27 (IL27

Interleukin 27

Interleukin-27 is a heterodimeric cytokine belonging to the IL-12 family that is composed of two subunits, Epstein-Barr virus -induced gene 3 and IL27-p28 ....

) and IL35

Interleukin 35

Interleukin 35 is an IL-12 family cytokine that is produced by regulatory, but not effector, T cells and plays a role in immune suppression. It is a dimeric protein composed of IL-12α and IL-27β chains, which are encoded by two separate genes called IL12A and EBI3, respectively. Secreted by...

. IL27 is composed of p28 (IL27) and EBI3. IL27 can trigger signaling in T cell

T cell

T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells , by the presence of a T cell receptor on the cell surface. They are...

s, B cell

B cell

B cells are lymphocytes that play a large role in the humoral immune response . The principal functions of B cells are to make antibodies against antigens, perform the role of antigen-presenting cells and eventually develop into memory B cells after activation by antigen interaction...

s, and myeloid cells. IL35, an inhibitory cytokine involved in regulatory T-cell function, is composed of EBI3 and the p35 subunit of IL12

IL12A

Interleukin-12 subunit alpha is a protein that in humans is encoded by the IL12A gene.-Further reading:...

.

Further reading