SHP-1, a protein-tyrosine phosphatase with two srchomology 2 domains, is expressed predominantly in hematopoietic and epithelial cells and has been implicated in numerous signaling pathways as a negative regulator. Two promoters direct the expression of human and murine SHP-1, and two types of transcripts (I) and (II) SHP-1, are initiated from each of these promoters. The cDNA sequences of (I)SHP-1 and (II)SHP-1 are identical except in the 5¢ untranslated region and in the first few coding nucleotides. In this report, we show that promoter usage is similar in mouse and human hematopoietic cells, but different in epithelial cells. In human.
