Organization of the human interleukin-1 receptor antagonist gene IL1HY1.

The interleukin (IL)-1 family of proteins plays an important role in inflammatory and defense mechanisms. The recently characterized IL1HY1 cDNA encodes a new member of the IL-1 receptor antagonist family (IL-1ra). In this report, we describe the complete nucleotide sequence of the human IL1HY1 gene. We sequenced approximately 7,600 nucleotides and found four coding exons ranging in size from 55 to 2,288 nucleotides. The 5' untranslated region is formed by one of two alternatively used exons and one invariably present exon which also contains the region encoding the first nine amino acids of the protein. IL1HY1 and IL-1ra intron positions are well conserved within the protein-coding region, providing evidence that these genes arose from a duplication of a primordial IL-1 receptor antagonist gene.