Alternative titles; symbols
HGNC Approved Gene Symbol: KIR3DP1
Cytogenetic location: 19q13.42 Genomic coordinates (GRCh38) : 19:54,786,362-54,790,418 (from NCBI)
Killer cell Ig-like receptors (KIRs) enable natural killer cells to survey the expression of individual HLA class I molecules. KIR genes cluster in a 150-kb region of chromosome 19q13.4, and the organization of the KIR gene cluster varies extensively among individuals. KIR3DP1 is designated a pseudogene because its RNA is normally undetectable in peripheral blood mononuclear cells (PBMCs). However, some individuals have a duplication of the KIR3DP1-KIR2DL4 (604945)-KIR3DL1 (604946)/KIR3DS1 (620778) gene cluster that is associated with a functional KIR3DP1 gene (Gomez-Lozano et al., 2005). For further background information on KIRs, see 604936.
Gomez-Lozano et al. (2005) noted that some individuals possess 3 alleles of KIR2DL4 and KIR3DL1/KIR3DS1, and that most of these individuals lack the downstream genes KIR2DL5A (605305), KIR2DS5 (604956), and KIR2DS1 (604952). Using a gene-walking approach, they found that, in most of these individuals, KIR3DS1 is followed by a chimeric KIR gene containing a 5-prime end (promoter region, exon 1, and intron 1) derived from KIR2DL5A and a 3-prime end corresponding to a KIR3DP1 allele, KIR3DP1*001. Screening of unrelated Spanish Caucasoid donors revealed a frequency of 4.5% for the recombinant KIR3DP1 allele. RT-PCR of PBMCs from individuals carrying the recombinant KIR3DP1 allele produced transcripts of 1.0 and 0.7 kb, corresponding to full-length KIR3DP1 and KIR3DP1 lacking exon 3, respectively. Using RT-PCR and 3-prime RACE, Gomez-Lozano et al. (2005) obtained a cDNA for full-length KIR3DP1, which they designated KIR3DP1*004. KIR3DP1*004 contains 6 exons and encodes a predicted 328-amino acid protein containing D0, D1, and D2 Ig-like domains, followed by a 12-residue tail. The hydrophilic tail has a high proportion of charged amino acids and other features that preclude anchoring to the cell membrane, suggesting that KIR3DP1*004, like LILRA3 (604818), is secreted as a soluble receptor. Exon 6 of KIR3DP1*0004, which encodes the hydrophilic tail, has homology with chimpanzee KIR homologs, but not with other human KIRs.
By genomic sequence analysis, Gomez-Lozano et al. (2005) mapped the KIR3DP1 gene within the KIR gene cluster on chromosome 19q13.4.
Gomez-Lozano, N., Estefania, E., Williams, F., Halfpenny, I., Middleton, D., Solis, R., Vilches, C. The silent KIR3DP1 gene (CD158c) is transcribed and might encode a secreted receptor in a minority of humans, in whom the KIR3DP1, KIR2DL4 and KIR3DL1/KIR3DS1 genes are duplicated. Europ. J. Immun. 35: 16-24, 2005. [PubMed: 15580659] [Full Text: https://doi.org/10.1002/eji.200425493]