Conserved Site

Long hematopoietin receptor, soluble alpha chain, conserved site (IPR003530)

Short name: Hematopoietin_rcpt_L_F3_CS


A number of receptors for lymphokines, hematopoietic growth factors and growth hormone-related molecules have been found to share a common binding domain. These receptors are designated as hematopoietin receptors [PMID: 1400369] and the corresponding ligands as hematopoietins. Further, hematopoietins have been subdivided into two major structural groups: Large/long and small/short hematopoietins.

One subset of individual receptor chains that are part of receptor complexes for large hematopoietins contain common structural elements in their extracellular parts: an immunoglobulin-like domain at the N-terminal end of the hematopoietin receptor domain (except for the EBCV-induced interleukin-12 beta chain) and a short (or no) cytoplasmic domain. They define a structural subgroup containing the following chains: Interleukin-6 receptor alpha chain (IL6RA). Interleukin-11 receptor alpha chain (IL11RA), Ciliary neurotrophic factor receptor alpha chain (CNTFRA), Interleukin-12 beta chain p40 (IL12BC), Interleukin-12 beta chain induced by Epstein-Barr virus (strain GD1) (HHV-4) (Human herpesvirus 4).

Members of this subgroup bind to their cognate cytokines with low affinity and possess transmembrane and short cytoplasmic domains (IL6RA and IL11RA), or are GPi-linked membrane proteins (CNTFRA). Truncated soluble forms of IL-6 and CNTF receptors alpha chains are physiologically active [PMID: 8293462]. IL-12 is an heterodimeric cytokine made of an alpha chain (p35) and a beta chain (p40). p40 (IL12BC) can be regarded as an alpha chain receptor devoid of cytoplasmic domain [PMID: 2070420]. Members of this family have the ability to bind corresponding cytokines with no signalling function.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004896 cytokine receptor activity

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns