Fig. 4

Domain organization of Xenopus Ceacam proteins. The domain organization of Ceacam family members from X. tropicalis and X. laevis was predicted by gene analysis only (domains shown in light colors) or, where available, confirmed by EST and cDNA sequences (domains shown in intense colors). Only Ceacams whose complete domain organization could be delineated were included. Homeologous Ceacams in X. laevis arisen by hybridization during speciation are discriminated by L (encoded on long chromosome variant 7) and S (encoded on short chromosome variant 7). For comparison the domain organization of human CEACAM proteins is shown. The conserved human CEACAM family members are highlighted in green. IgV-like domains are shown as red, IgC-like domains are blue ovals. The predicted signaling motifs in the cytoplasmic domains are schematically shown as green (ITAM), blue (ITAM-like motif), red (ITIM) and yellow boxes (ITSM). Transmembrane domains and GPI anchors are indicated by black and green lines, respectively. Orthologous relationship as suggested by sequence relatedness and/or synteny is indicated by gray boxes. Note that Xtr_Ceacam301 and Xla_Ceacam326 appear to represent orthologs based on the degree of N domain sequence identity (see Fig. 3) despite their different domain organization. Paired receptors identified by their similar N domain sequences and the presence of ITIM/ITSM or ITAM/ITAM-like motifs are connected by gray lines. C, CEACAM or Ceacam; P, PSG