Figure 1.

Amino acid sequences and evolutionary relationships of the angiopoietins and their distant relatives. (A) Full-length sequences of the definitive angiopoietins as aligned by the clustal method by using the megalign program from DNAstar; arrowhead marks the predicted signal peptide cleavage site, bent arrows indicate the limits of the coiled–coil and fibrinogen-like domains, closed circles denote conserved cysteines, and the open circle marks a cysteine present in Ang1 but absent in all other angiopoietins. (B) Alignment of the conserved fibrinogen-like domain of all definitive members of the angiopoietin family with the fibrinogen-like domains of the more distant angiopoietin homologs described here (AngX and AngY), as well as of previously described members of the fibrinogen superfamily (i.e., ficolin-a, ficolin-b, hFrep, hpt49, and human fibrinogen γ); dots mark the three distinctive cysteines that are present in the angiopoietin family but absent from AngX and AngY, as well as all other members of the fibrinogen superfamily. For ease of alignment, some amino acids were deleted in the alignments: in PT49 a “g” was deleted after the boldfaced “n,” in FREP the sequence “dslagnf” was deleted before the boldfaced “h,” and in fibrinogen the sequence “sdkfftshng” was deleted after the boldfaced “p.” (C) Cladogram (built by the clustal method by using the megalign program from DNAstar) comparing the evolutionary relationships between members of the angiopoietin family and the distant relatives depicted in B; also indicated are the percent amino acid identity between paired orthologs or between the distant relatives and their closest angiopoietin homolog (only within the fibrinogen-like domain) as well as the chromosomal localizations of the paired ortholog in both mouse and human.