Interleukin-12 subunit alpha (IL-12 p35) is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''IL12A''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Function

This gene encodes a subunit of the

cytokine Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...

Interleukin 12 Interleukin 12 (IL-12) is an interleukin that is naturally produced by dendritic cells, macrophages, neutrophils, and human B- lymphoblastoid cells ( NC-37) in response to antigenic stimulation. IL-12 belongs to the family of interleukin-12. I ...

(IL-12) that acts on T and

natural killer cell Natural killer cells, also known as NK cells or large granular lymphocytes (LGL), are a type of cytotoxic lymphocyte critical to the innate immune system that belong to the rapidly expanding family of known innate lymphoid cells (ILC) and repres ...

s, and has a broad array of biological activities. The cytokine is a disulfide-linked

heterodimer In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has ...

composed of the 35-kD subunit encoded by this gene, and a 40-kD subunit that is a member of the cytokine receptor family. This cytokine is required for the T-cell-dependent induction of

interferon gamma Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock ...

(IFN-γ), and is important for the differentiation of both Th1 and Th2 cells. The responses of

lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ad ...

s to this cytokine are mediated by the activator of transcription protein

STAT4 Signal transducer and activator of transcription 4 (STAT4) is a transcription factor belonging to the STAT protein family, composed of STAT1, STAT2, STAT3, STAT5A, STAT5B, STAT6. STAT proteins are key activators of gene transcription which bind ...

. Nitric oxide synthase 2A ( NOS2A/NOS2) is found to be required for the signaling process of this cytokine in

innate immunity The innate, or nonspecific, immune system is one of the two main immunity strategies (the other being the adaptive immune system) in vertebrates. The innate immune system is an older evolutionary defense strategy, relatively speaking, and is the ...

Function

References

Further reading