Molecular cloning and characterization of a novel mammalian endo-apyrase (LALP1)

Here we describe the cloning, localization, and characterization of a novel mammalian endo-apyrase (LALP1) in human and mouse. The predicted human LAL P1 gene encodes a 604-amino acid protein, whereas the mouse Lalp1 gene enco des a 606-amino acid protein. The human and mouse genes have 88% amino acid sequence identity. These genes share considerable homologies with hLALP70, a recently discovered mammalian lysosomal endo-apyrase, The human LALP1 ge ne resides on chromosome 10q23-q24 and contains 12 exons and 11 introns cov ering a genomic region of similar to 46 kilobase pairs. The subcellular loc alization and enzymatic activity of LALP1 indicated that LALP1 is indeed an endo-apyrase with substrate preference for nucleoside triphosphates UTP, G TP, and CTP.