EGF Like Domain Protein, Multiple 7 (EGFL7)

The deduced 275-amino acid protein has a calculated molecular mass of 29.8 kD. The mouse and human EGFL7 proteins both contain an N-terminal cleavable signal peptide followed by 2 epidermal growth factor (EGF)-like domains, and they share 78% amino acid identity. Northern blot analysis detected a transcript of about 1.6 kb only in mouse heart, lung, and kidney. In situ hybridization showed mouse Egfl7 expressed at embryonic day 7.5 exclusively in the primitive blood islands where the first endothelial cells differentiate, and later in endothelial cells of a wide range of tissues. Fluorescence-labeled Egfl7 was expressed in the endoplasmic reticulum of transfected mouse fibroblasts, and it was secreted into the culture medium.