Type II cytokine receptors are transmembrane 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...

s that are expressed on the surface of certain cells, which bind and respond to a select group of 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. These receptors are similar to type I cytokine receptor

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 common amino acid motif in the extracellular portion...

s except they do not possess the signature sequence WSXWS that is characteristic of type I receptors.

Structure

Typically type II cytokine receptors are heterodimers or multimers with a high and a low affinity component. Currently no complete structure of the extracellular domains of a type II cytokine receptor is available. These receptors are related predominantly by sequence similarities in their extracellular

Extracellular

In cell biology, molecular biology and related fields, the word extracellular means "outside the cell". This space is usually taken to be outside the plasma membranes, and occupied by fluid...

 portions that are composed of tandem Ig-like domains. The intracellular

Intracellular

Not to be confused with intercellular, meaning "between cells".In cell biology, molecular biology and related fields, the word intracellular means "inside the cell".It is used in contrast to extracellular...

 domain of type II cytokine receptors is typically associated with a tyrosine kinase

Tyrosine kinase

A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to a protein in a cell. It functions as an "on" or "off" switch in many cellular functions....

 belonging to the Janus kinase

Janus kinase

Janus kinase 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 & 2 , but were ultimately published as "Janus kinase"...

 (JAK) family.

Types

Type II cytokine receptors include those that bind type I and type II interferon

Interferon

Interferons are proteins made and released by host cells in response to the presence of pathogens—such as viruses, bacteria, or parasites—or tumor cells. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.IFNs belong to...

s, and those that bind members of the interleukin-10 family (interleukin-10, interleukin-20 and interleukin-22).

Interferon receptors

The interferon receptor is a molecule displayed on the surface of cells which allows them to interact with the anti-viral substance interferon. The receptor is genetically coded for by number of different genes, as there are a few distinct types of interferon. Interferon receptor deficiency is a condition showing some amenability to genetic therapy.

• interferon-alpha/beta receptor
  Interferon-alpha/beta receptor
  The interferon-α/β receptor is a receptor which binds type I interferons including interferon-α and -β. It is a heteromeric receptor composed of one chain with two subunits referred to as IFNAR1 and IFNAR2. It is a cell surface receptor. Binding of cytokine follows a JAK-STAT signaling pathway...
  
  
• interferon-gamma receptor
  Interferon-gamma receptor
  The interferon-gamma receptor is a receptor which binds interferon-γ, the sole member of interferon type II.- Structure and function :...