IDENTIFICATION OF A 2ND SH2-DOMAIN-CONTAINING PROTEIN CLOSELY-RELATEDTO THE PHOSPHATIDYLINOSITOL POLYPHOSPHATE 5-PHOSPHATASE SHIP

Distinct inositol and phosphatidylinositol polyphosphates B-phosphatas es have recently been cloned. Primers have been designed coding for hi ghly conserved amino acid regions that are shared between sequences of B-phosphatases. One of the PCR fragment referred to as 51 C, shows 99 % identity to a previously reported sequence (INPPL-1) present in the database. We report here the identification of cDNAs for a new SH2-do main-containing protein showing homology to the inositol B-phosphatase SHIP and therefore referred to as SHIPS. SHIPS differs at both N- and C-terminal ends with the sequence of INPPL-1. The translated sequence of SHIPS encodes a 1258 amino acid protein with a predicted molecular mass of 142 kDa. Particularly high levels of SHIPS were found in huma n heart, skeletal muscle and placenta as shown by Northern blot analys is. SHIPS was also expressed in dog thyroid cells in primary culture w here the expression was enhanced in TSH and EGF-stimulated cells. (C) 1997 Academic Press.