Molecular cloning of a novel human leukemia-associated gene. Evidence of conservation in animal species.

We have recently described an 18-kilodalton polypeptide (p18) that is present in much greater abundance in acute leukemic blast cells (myeloid and lymphoid) than in resting or proliferating nonleukemic lymphoid cells or chronic lymphoid and myeloid leukemic cells. In this report we describe the cloning of two different sized full-length cDNAs that code for p18. The two cDNAs differ in their 3'-noncoding regions as a result of alternative polyadenylation. Analysis of the complete nucleotide sequence and the corresponding amino acid sequence did not reveal significant homology to any previously described sequences. We show evidence that this gene is highly conserved in several animal species and low stringency hybridization studies suggest that the p18 gene may be a member of a family of partially homologous genes in the human genome.