Identification of six new polymorphisms in the human coronavirus 229E receptor gene (aminopeptidase N/CD13)()

Objective: Human aminopeptidase N (APN/CD13/ANPEP) has been identified as the receptor for human coronavirus (HCoV) 229E. In this study, we analyzed the region of the APN gene that encodes a stretch of amino acid residues, essential for its HCoV-229E receptor function (amino acids 260–353). Methods: Full-length APN exon 3, intron 3 and exon 4, was PCR-amplified and sequenced in DNA samples from 100 unrelated Caucasian Belgian healthy volunteers. Results: We identified seven polymorphisms, including four intron 3 and three exon 4 variations. Apart from the already known C956T exon 4 mutation, the six other polymorphisms have not yet been described. The most prevalent APN variations in this population (C956T leading to an alanine to valine substitution, G978T, G987A and intron3-C389T) always occurred together at an allele frequency of 8.5%. Haploid DNA sequencing demonstrated the presence of these four variations on the same allele. Three polymorphisms in intron 3, intron3-G395C, intron3-C86T, and intron3-C429T, were identified with an allele frequency of 3.5%, 1% and 0.5% respectively. Five haplotypes were identified in the population of 100 individuals. Conclusion: These results demonstrate that there is a relatively broad spectrum of variations in the APN domain critical for coronavirus binding. The nucleotide sequence reported here has been submitted to the GenBank database with the following accession number: AF527789.