The mouse SHIP2 (InppI1) gene: Complementary DNA, genomic structure, promoter analysis, and gene expression in the embryo and adult mouse

SHIP2 is a new member of the inositol polyphosphate 5-phosphatase family sh owing homology to SHIP1. The structure of both enzymes is characterized by the presence of a 5' SH2 domain, a central catalytic domain, and a 3' proli ne-rich region. Recent results suggest that SHIP2 and SHIP1 act downstream of various receptors by removing a phosphate from the 5' position of the ph osphatidylinositol 3'-kinase phosphatidylinositol 3,4,5-triphosphate produc t and of inositol 1,3,4,5-tetrakisphosphate. Human SHIP2 is highly expresse d in adult heart, skeletal muscle, and placenta, whereas SHIP1 expression i s limited to the hematopoietic system. We report here the molecular analysi s of the mouse SHIP2 cDNA and the corresponding protein, the structure of t he gene, and the identification of its promoter. SHIP2 mRNA expression was analyzed in embryonic and adult mouse tissues by reverse transcription-poly merase chain reaction and in situ hybridization. In embryonic day 15.5 mice , SHIP2 was strongly expressed in the Liver, specific regions of the centra l nervous system, the thymus, the lung, and the cartilage perichondrium. In adult mice, SHIP2 mRNA was markedly present in the brain and the thymus an d at different stages of spermatozoa maturation in the seminiferous tubules . The subtle differences in the protein structure of SHIP2 and SHIP1 as wel l as their different patterns of expression are discussed, (C) 1999 Academi c Press.