Cytokine receptors are receptors that bind cytokines.[1]
In recent years, the cytokine receptors have come to demand the attention of more investigators than cytokines themselves, partly because of their remarkable characteristics, and partly because a deficiency of cytokine receptors has now been directly linked to certain debilitating immunodeficiency states. In this regard, and also because the redundancy and pleiotropy of cytokines are, in fact, a consequence of their homologous receptors, many authorities are now of the opinion that a classification of cytokine receptors would be more clinically and experimentally useful.
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A classification of cytokine receptors based on their three-dimensional structure has been attempted. (Such a classification, though seemingly cumbersome, provides several unique perspectives for attractive pharmacotherapeutic targets.)
Type | Examples | Structure | Mechanism |
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type I cytokine receptor | Certain conserved motifs in their extracellular amino-acid domain. Connected to Janus kinase (JAK) family of tyrosine kinases | JAK phosphorylate and activate downstream proteins involved in their signal transduction pathways | |
type II cytokine receptor | |||
Many members of the immunoglobulin superfamily | Share structural homology with immunoglobulins (antibodies), cell adhesion molecules, and even some cytokines. | ||
Tumor necrosis factor receptor family | cysteine-rich common extracellular binding domain | ||
chemokine receptors |
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Seven transmembrane helix | G protein-coupled |
TGF beta receptors |
Cytokine receptors may be both membrane-bound and soluble. Soluble cytokine receptors are extremely common regulators of cytokine function.
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