Chemokine receptor

[3] Each has a rhodopsin-like 7-transmembrane (7TM) structure and couples to G-protein for signal transduction within a cell, making them members of a large protein family of G protein-coupled receptors.

Approximately 19 different chemokine receptors have been characterized to date, which share many common structural features.

Although chemokine receptors share high amino acid identity in their primary sequences, they typically bind a limited number of ligands.

At the same time, the G-protein subunit Gα directly activates an enzyme called protein tyrosine kinase (PTK), which phosphorylates serine and threonine residues in the tail of the chemokine receptor, causing its desensitisation or inactivation.

[7] The initiated MAP kinase pathway activates specific cellular mechanisms involved in chemotaxis, degranulation, release of superoxide anions, and changes in the avidity of cell adhesion molecules called integrins.

[6] Chemokines and their receptors play a crucial role in cancer metastasis as they are involved in extravasation, migration, micrometastasis, and angiogenesis.

An unusually high frequency of this allele is found in European Caucasian population, with an observed cline towards the north.

[8] Most researchers have attributed the current frequency of this allele to two major epidemics of human history: plague and smallpox.

Many in vivo mouse studies have refuted this claim by showing no protective effects of CCR5-Δ32 allele in mice infected with Y.

[8] From an evolutionary viewpoint, this results in greater loss of reproductive potential from a population which may explain increased selective pressure by smallpox.