MOLECULAR-CLONING AND CHROMOSOMAL ASSIGNMENT OF THE HUMAN BRAIN-TYPE PHOSPHODIESTERASE-I NUCLEOTIDE PYROPHOSPHATASE GENE (PDNP2)

Phosphodiesterase I/nucleotide pyrophosphatase is a widely expressed m embrane-bound enzyme that cleaves diester bonds of a variety of substr ates. We have cloned brain-type cDNA for this enzyme from rat brain an d designated it PD-I alpha (M. Narita, J. Goji, H. Nakamura, and K. Sa ne, 1994, J. Biol. Chem. 269: 28235-28242). In this study we have isol ated cDNA and genomic DNA encoding human PD-I alpha. Human PD-I alpha cDNA, designated PDNP2 in HGMW nomenclature, has a 2589-nucleotide ope n reading frame encoding a polypeptide of 863 amino acids with a calcu lated M(r) of 99,034. Northern blot analysis revealed that human PD-I alpha transcript was present in brain, lung, placenta, and kidney. The database analysis showed that human PD-I alpha was identical with hum an autotaxin (ATX), a novel tumor motility-stimulating factor, except that human PD-I alpha lacks 156 nucleotides and 52 amino acids of huma n ATX. Human PD-I alpha and human ATX are likely to be alternative spl icing products from the same gene. The 5' region of the human PDNP2 ge ne contains four putative binding sites of transcription factor Sp1 wi thout typical TATA or CAAT boxes, and there is a potential octamer bin ding motif in intron 2. From the results of fluorescence in situ hybri dization, the human PDNP2 gene is located at chromosome 8q24.1. (C) 19 95 Academic Press, Inc.