Molecular cloning of murine BST-1 having homology with CD38 and Aplysia ADP-ribosyl cyclase.

Human BST-1, a bone marrow stromal cell surface antigen, is a glycosyl-phosphatidylinositol-anchored protein that facilitates the growth of pre-B cells. We report here the molecular cloning of murine BST-1 cDNA. The deduced amino acid sequence of murine BST-1 had 71% similarity with human BST-1 and 30 and 25% similarity with CD38 and Aplysia adenosine diphosphate-ribosyl cyclase, respectively. Murine BST-1 mRNA was expressed in the bone marrow, spleen and thymus in lymphoid organs, and the lung, kidney and heart in non-lymphoid organs. Restriction fragment length polymorphism (RFLP) was shown in BALB/c, DBA/2 and NZB vs C57BL/6, A/J, CBA/N, NZW, BXSB and MRL/lpr. RFLP was mapped to the 5' portion of the murine BST-1 gene.