Molecular cloning and characterization of a novel angiopoietin family protein, angiopoietin-3

Using homology-based PCR, we have isolated cDNA encoding a novel member (49 1 amino acids) of the angiopoietin (Ang) family from human adult heart cDNA and have designated it angiopoietin-3 (Ang3). The NH2-terminal and COOH-te rminal portions of Ang-3 contain the characteristic coiled-coil domain and fibrinogen-like domain that are conserved in other known Angs. Ang3 has a h ighly hydrophobic region at the N-terminus (similar to 21 amino acids) that is typical of a signal sequence for protein secretion. Ang3 mRNA is most a bundant in adrenal gland, placenta, thyroid gland, heart and small intestin e in human adult tissues. Additionally, Ang3 is a secretory protein, but is not a mitogen in endothelial cells. (C) 1999 Federation of European Bioche mical Societies.