New nomenclature for atypical chemokine receptors

Chemokine receptors, the largest family of receptors containing a seven-transmembrane domain that are expressed on leukocytes, can be categorized into two principal subgroups that are highly related phylogenetically and cluster in the same branch of class A rhodopsin-like receptors: a larger subgroup (eighteen in humans) of G protein– coupled leukocyte chemotactic receptors, and a smaller subgroup (four in humans) of atypical chemokine receptors that do not signal through G proteins and lack chemotactic activity. Standard nomen¬clature for chemokine receptors was approved 13 years ago by the Nomenclature Committee of the International Union of Pharmacology and has been universally accepted by the scientific community1. However, even though members of the smaller subgroup of recep¬tors also bind chemokines with high affinity, they were excluded from the standard nomenclature system because evidence of signaling was originally absent and was ultimately found to be atypical, occur¬ring in some cases through pathways not dependent on G proteins. No other standardized nomenclature for them emerged, despite some effort by the Human Genome Organization Gene Nomenclature Committee and others. Instead, since they seem to act by scavenging chemokines as an important shared function, they have been referred to by immunologists over the years collectively and alternatively as ‘chemokine-binding proteins’, ‘decoys’, ‘scavengers’ and ‘interceptors’. The use of such competing nonstandard terms has caused confu¬sion and has delayed recognition of these molecules as a functionally related group2. To address this problem, in 2012 we formed a com¬mittee broadly representative of scientists in this field, to establish a standard nomenclature. After extensive deliberation and consultation, the committee voted unanimously to adopt the unique designation stem ‘ACKR’, an abbreviation of ‘atypical chemokine receptor’. This nomenclature has now been approved by Human Genome Organization Gene Nomenclature Committee and Nomenclature Committee of the International Union of Pharmacology and was first announced in a review article published by Pharmacological Reviews3. Approval by the Nomenclature Committee of the International Union of Immunological Societies is pending.