CXCR3
| CXCR3 | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 368 AS ; 40.7 kDa | |
| Secondary to quaternary structure | 7TM | |
| Identifier | ||
| Gene names | CXCR3 , CD183 | |
| External IDs | ||
| Occurrence | ||
| Parent taxon | Vertebrates | |
CXCR3 (short for CXC motif chemokine receptor 3 , also CD183 ) is a receptor protein from the chemokine receptor family . CXCR3 occurs particularly on the surface of cells of the immune system , such as T lymphocytes and natural killer cells . This receptor can be stimulated by the chemokines CXCL9 (MIG), CXCL10 (IP-10) and CXCL11 (I-TAC) and mediates its effects by activating an intracellular signal transduction cascade in which G i proteins are involved. CXCR3 plays an important role in the development of inflammatory diseases and is therefore a target for the development of new drugs .
Occurrence
CXCR3 can be detected on various lymphocytes, in particular activated T lymphocytes and NK cells, as well as on epithelial and endothelial cells within the hematopoietic system. Together with the chemokine receptor CCR5 , CXCR3 is preferably found on the type 1 T helper cells (T H1 lymphocytes) responsible for the cell-mediated immune defense .
biochemistry
CXCR3 is encoded by a gene on chromosome 10 gene locus q13. Two different isoforms of CXCR3 are known, which result from different splicing : CXCR3-A and CXCR3-B. Both isoforms differ in the length of their N-terminal amino acid sequences . CXCR3-B is also able to bind the chemokine CXCL4 (PF-4).
Structurally, CXCR3 is one of the G protein-coupled receptors . After the chemokines CXCL9, CXCL10 or CXCL11 have been attached, a signal transduction cascade is activated inside the cell, in which G proteins, Ca 2+ and MAP kinases are involved. The signal transduction cascade also includes activation of integrins and changes in the cytoskeleton. These are prerequisites for a targeted movement ( chemotaxis ) of CXCR3-expressing cells towards a chemokine gradient during inflammation.
Individual evidence
- ↑ Qin S, Rottman JB, Myers P, et al : The chemokine receptors CXCR3 and CCR5 mark subsets of T cells associated with certain inflammatory reactions . In: J. Clin. Invest. . 101, No. 4, February 1998, pp. 746-754. doi : 10.1172 / JCI1422 . PMID 9466968 . PMC 508621 (free full text).
- ↑ Lasagni L, Francalanci M, Annunziato F, et al : An alternatively spliced variant of CXCR3 mediates the inhibition of endothelial cell growth induced by IP-10, Mig, and I-TAC, and acts as functional receptor for platelet factor 4 . In: J. Med.. . 197, No. 11, June 2003, pp. 1537-1549. doi : 10.1084 / jem.20021897 . PMID 12782716 . PMC 2193908 (free full text).