Gene structure and promoter variation of expressed and nonexpressed variants of the KIR2DL5 gene

Two variants of the novel KIR2DL5 gene (KIR2DL5.1 and .2) were identified i n genomic DNA of a single donor. However, only the KIR2DL5.1 variant was tr anscribed in PBMC, In this study, analysis of seven additional donors revea ls two new variants of the KIR2DL5 gene and indicates that transcription, o r its lack, are consistently associated with particular variants of this ge ne. Comparison of the complete nucleotide sequences of the exons and intron s of KIR2DL5.1 and KIR2DL5.2 reveals no structural abnormalities, but simil ar open reading frames for both variants. In contrast, the promoter region of KIR2DL5 shows a high degree of sequence polymorphism that is likely rele vant for expression. Substitution within a putative binding site for the tr anscription factor acute myeloid leukemia gene 1 could determine the lack o f expression for some KIR2DL5 variants.