Cytokine Receptors

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology

Cytokine Receptors include the following types:

- Type I (hematopoietin receptors - IL-3 and Epo)
- Type II
- IL-1 family receptors - they share Toll-like/IL-1 receptor (TIR) domain
- TNF receptors
- Seven-transmembrane α-helical receptors

(click to enlarge the image)

Type I Cytokine Receptors

Type I are hemopoietin receptors, contain a domain with two cysteine residues and a sequence of tryptophan-serine-X-tryptophan-serine (WSXWS), where X is any amino acid. Bind cytokines that fold into four α-helical strands - type I cytokines.

All type I and type II cytokine receptors engage Jak-STAT signaling pathways.

Receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21 contain γ chain, which is affected in X-linked SCID.

Type II Cytokine Receptors

Type II are similar to type I (two extracellular domains with conserved cysteines) but do not contain the WSXWS motif. These receptors consist of one ligand-binding polypeptide chain and one signal-transducing chain.

All type I and II cytokine receptors engage Jak-STAT signaling pathways.

IL-1 family receptors

IL-1 family receptors share a cytosolic sequence, called the Toll-like/IL-1 receptor (TIR) domain.

TNF receptors

TNF receptors are part of a large family of proteins (some of which are not cytokine receptors) with trimeric, cysteine-rich extracellular domains.

G protein-coupled receptors

Seven-transmembrane α-helical receptors are also called serpentine receptors, because their transmembrane domains "snake" back and forth through the membrane. Also called G protein-coupled receptors because their signaling pathways involve guanosine triphosphate (GTP)-binding proteins (G proteins). Involved in many types of cellular responses and typically produce a rapid and transient response.


Cellular and Molecular Immunology, Abbas et al., 2009.

Published: 04/09/2010
Updated: 08/14/2010

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