CLONING AND MAPPING OF A HUMAN AND MOUSE GENE WITH HOMOLOGY TO ECTO-ATPASE GENES

The human CD39-like-1 gene (CD39L1) was isolated from a selected cDNA library enriched for transcripts from regions of human Chromosome (Chr ) 9q. Database searches with sequences of one group of clones from the selected cDNA library showed strong amino acid homology to the lympho id cell activation antigen CD39, an ecto-apyrase gene from human and m ouse. The full-length sequence for CD39L1 identified a putative 472 am ino acid protein with greater than 60% identity with the chicken muscl e ecto-ATPase protein, as well as homology to a number of other known ecto-ATPases and ecto-apyrases from rat, garden pea, yeast, and Toxopl asma gondii. A high level of amino acid identity suggests that CD39L1 is closely related to the chicken muscle ecto-ATPase. The presence of the human ABC2 gene on an overlapping cosmid and hybridizations to som atic cell mapping panels suggest that CD39L1 maps to human Chr 9q34. A mouse homolog was isolated (showing greater than 78% nucleotide seque nce identity) and mapped by FISH to mouse Chr 2, the syntenic region o f human 9q34. The genomic structure of CD39L1 reveals 9 exons covering less than 7 kb.