Molecular characterisation of KIR2DS2005, a fusion gene associated with a shortened KIR haplotype

• Published in: Genes and immunity Vol. 12; no. 7; pp. 544 - 551
• Main Authors: Ordóñez, D, Gómez-Lozano, N, Rosales, L, Vilches, C
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.10.2011
• Subjects: Alleles; Allotypes; Base Sequence; Epitopes; European Continental Ancestry Group - genetics; Evolution; Female; Fusion protein; Gene Expression Regulation; Gene Fusion; Gene Order; Genes; Genetic aspects; Haplotypes; Humans; Immunoglobulins; Introns; Killer cell immunoglobulin-like receptors; Lymphocytes; Lymphocytes T; Major histocompatibility complex; Molecular Sequence Data; Monoclonal antibodies; Mutation; Physiological aspects; Polymerase chain reaction; Polymorphism; Population studies; Potassium channels (inwardly-rectifying); Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; Receptors, KIR - genetics; Receptors, KIR - metabolism; Recombination; Sequence Alignment; Surveys; Spain
• ISSN: 1466-4879; 1476-5470
• DOI: 10.1038/gene.2011.35

KIR2DS2 is an activating homologue of KIR2DL2, an inhibitory killer-cell immunoglobulin-like receptor (KIR) that surveys expression of major histocompatibility complex-C allotypes bearing a C1 epitope. We have studied here its allele KIR2DS2*005, which shows a hybrid structure-it is identical to other KIR2DS2 alleles in the ectodomain, but has transmembrane and cytoplasmic regions identical to those of KIR2DS3(*)001, a short-tailed KIR of uncertain expression and function. Our results reveal that KIR2DS2*005 is a fusion gene-the product of an unequal crossing over by which the genes KIR2DS2 and KIR2DS3 recombined within a 400 base pair region of complete identity in intron 6. Also resulting from that recombination was a shortened KIR haplotype of the B group, in which three genes commonly linked to KIR2DS2 (KIR2DL2, KIR2DL5B and KIR2DS3) are deleted. Population studies indicate that KIR2DS2*005 is still associated to such haplotype, and it can be found in approximately 1.2% of Caucasoids. Using a combination of two monoclonal antibodies, we also demonstrate that KIR2DS2*005 encodes a molecule expressed on the surface of natural killer- and T-lymphocytes.