Abstract
The human leukocyte receptor complex (LRC) at Chromosome 19q13.4 encodes Ig superfamily proteins which regulate the function of various hematopoietic cell types. We investigated characteristics of the Ig-like transcript (ILT)/leukocyte Ig-like receptor (LIR) group of LRC genes in comparison with the other major LRC loci encoding the killer cell Ig-like receptors (KIRs). In direct contrast to KIR genes, the ILT/LIR loci of ethnically diverse individuals did not display haplotypic variations in gene number. Investigation of gene expression identified novel cDNA sequences related to the ILT2/LIR1, ILT4/LIR2, ILT3/LIR5, and ILT7 loci, while phylogenetic analysis revealed two distinct lineages of ILT/LIR genes. These two lineages differ in both the nature and extent of their sequence polymorphism. The presence of certain transcription factor-related motifs in the 5' untranslated region of ILT/LIR cDNAs correlates with the specific cell types in which particular ILT/LIR genes are expressed. Although extensive gene duplications and conversion events have apparently forged the LRC, our results indicate striking conservation in the organization of the ILT/LIR genes when compared with the related and closely linked KIR genes. This suggests the evolutionary maintenance of a significant function consistent with the cellular distribution of the ILT/LIR proteins.
| Original language | English |
|---|---|
| Pages (from-to) | 270-278 |
| Number of pages | 9 |
| Journal | Immunogenetics |
| Volume | 53 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2001 |
Keywords
- Base Sequence
- Conserved Sequence
- Evolution, Molecular
- Haplotypes
- Humans
- Leukocytes
- Molecular Sequence Data
- Multigene Family
- Phylogeny
- Polymorphism, Genetic
- Receptors, Immunologic
- Sequence Analysis, DNA
- Genes
- Leukocyte receptor complex
- LTR
- ILT
- Polymorphism