Interleukin-17 receptor

interleukin 17 receptor A
Crystal structure of a complex of IL-17RA bound to IL-17F in a 1:2 stoichiometry.
Identifiers
Symbol	IL17RA
Alt. symbols	IL17R, CDw217
Entrez	23765
HUGO	5985
OMIM	605461
RefSeq	NM_014339
UniProt	Q96F46
Other data
Locus	Chr. 22 q11.1

Interleukin-17 receptor (IL-17R) is a cytokine receptor which binds interleukin 17A. Functional IL-17R is a heteromeric complex consisting of at least IL17RA and IL17RC.

A number of additional variants exist including IL17RB, which binds preferentially IL17B and IL17E. A total of five members of the family have been identified. The first identified member, IL-17RA is located on human chromosome 22.

There are two IL17Rs (IL17RA and IL17RD) in the genome of the basal chordate Amphioxus. After two rounds of whole genome duplications, these two IL17R genes expanded into five early vertebrate IL17R genes, IL17RA to IL17RE. Two (IL17RA and IL17RD) are found in most vertebrates, whereas the other three (IL17RB, ILR17RC and IL17RE) have undergone some losses in vertebrates during evolution.

IL-17RA is the founding member of a new IL-17R(A-E) subfamily of cytokine receptors. IL-17RA is by far the largest member of the family and has the largest cytoplasmic tail of the family. This cytoplasmic tail provides docking sites for numerous signaling intermediates. IL-17RA is composed of both alpha helices and beta sheets and has fibronectin domains, beta-sandwich domains, and ectodomains.

IL-17 RA has been observed at high levels in certain tissues such as: haematopoietic, bone marrow, thymus, and spleen tissue. IL-17 RA is also normally found in low levels in colon, small intestine, and lung tissues.

IL-17RA is expressed in CD8+ T cells, and upregulated by IL-15 and IL-21. IL-17RA may be internalised after binding IL-17A.

IL-17RC expression is low in haematopoietic tissues and high in non-immune cells of the prostate, liver, kidney, thyroid and joints.

As of 2010^[update] IL-17A neutralizing antibodies have the potential for the treatment of autoimmune diseases in humans. It also may soon be used for protection against periodontal bone loss as it is currently being tested in mice. IL-17 RA has been observed at high levels in people undergoing treatment for cardiac fibroblasts and in certain tissues such as: haematopoietic, bone marrow, thymus, and spleen tissue.