Type II cytokine receptors, also commonly known as class II cytokine receptors, are

transmembrane A transmembrane protein is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently u ...

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

s that are expressed on the surface of certain cells. They bind and respond to a select group of

cytokine Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...

s including

interferon type I The type-I interferons (IFN) are cytokines which play essential roles in inflammation, immunoregulation, tumor cells recognition, and T-cell responses. In the human genome, a cluster of thirteen functional IFN genes is located at the 9p21.3 cy ...

interferon type II Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cell (biology), cell ...

interferon type III The type III interferon group is a group of anti-viral cytokines, that consists of four IFN-λ (lambda) molecules called IFN-λ1, IFN-λ2, IFN-λ3 (also known as IL29, IL28A and IL28B respectively), and IFN-λ4. They were discovered in 2003. Their ...

. and members of the interleukin-10 family These

receptor Receptor may refer to: * Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and respond ...

s are characterized by the lack of a WSXWS motif which differentiates them from

type I cytokine receptor Type I cytokine receptors are transmembrane receptors expressed on the surface of cells that recognize and respond to cytokines with four α-helical strands. These receptors are also known under the name '' hemopoietin receptors'', and share a ...

Structure

Typically type II cytokine receptors are

heterodimers In biochemistry, a protein dimer is a macromolecular complex or multimer 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 ...

or multimers with a high and a low affinity component. These receptors are related predominantly by sequence similarities in their

extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

portions that are composed of tandem Ig-like domains. The structures for the

domains of the receptors for interferon types, I, II, and III are all known. Type II cytokine receptors are tyrosine-kinase-linked receptors. The

intracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

domain of type II cytokine receptors is typically associated with a

tyrosine kinase A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases belong to a larger cla ...

belonging to the

Janus kinase Janus kinase (JAK) is a family of intracellular, non-receptor tyrosine kinases that transduce cytokine-mediated signals via the JAK-STAT pathway. They were initially named "just another kinase" 1 and 2 (since they were just two of many discoverie ...

(JAK family). Binding of the receptor typically leads to activation of the canonical JAK/STAT signaling pathway.

Types

Type II cytokine receptors include those that bind

interferon Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten ...

s and those that bind members of the interleukin-10 family ( interleukin-10, interleukin-20, interleukin-22, and interleukin-28). Expression of specific receptor varieties is highly variable across tissue types with some receptors being ubiquitously expressed and some receptors only expressed in specific tissues.

Interferon receptors

The interferon receptor is a molecule displayed on the surface of cells which interacts with extracellular interferons. Class II cytokine receptors bind type I, type II, and type III interferons. Type I interferons play important roles in both the adaptive and innate immune responses, prevent proliferation of pathogens, and have antiviral activities. Type II interferons help to modulate the immune system’s response to pathogens, and these interferons also respond to pathogens. Type III interferons induce a similar response to type I interferons, but their expression is limited to

epithelial cells Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

. The receptor is coded for by number of different genes, due to the diversity of types of interferons.

Regulation Regulation is the management of complex systems according to a set of rules and trends. In systems theory, these types of rules exist in various fields of biology and society, but the term has slightly different meanings according to context. Fo ...

of cell surface receptor levels plays an important role in the regulation and limiting of interferon signaling. *

interferon-alpha/beta receptor The interferon-α/β receptor (IFNAR) is a virtually ubiquitous membrane receptor which binds endogenous type I interferon (IFN) cytokines. Endogenous human type I IFNs include many subtypes, such as interferons-α, -β, -ε, -κ, -ω, and -ζ. ...

interferon-gamma receptor The interferon-gamma receptor (IFNGR) protein complex is the heterodimer of two chains: interferon gamma receptor 1, IFNGR1 and interferon gamma receptor 2, IFNGR2. It binds Interferon-gamma, interferon-γ, the sole member of interferon type II ...

* Interferon type III receptor

Interleukin receptors

Interleukin-10 receptor Interleukin-10 receptor (IL-10R) is a type II cytokine receptor. The receptor is tetrameric, composed of 2 α and 2 β subunits. The α subunit (encoded in the ''Il10ra gene)'' is expressed on haematopoietic cells (such as T, B, NK, mast, and d ...

* Interleukin-20 receptor * Interleukin-22 receptor * Interleukin-28 receptor

References

2 {{immunology-stub