Fig. 2. S. domuncula CD36/LIMPII receptor. (A) The deduced S. domuncula protein (CD36/LIMPII_SD) is aligned with the human lysosomal integral membrane protein II (LIMPII) (LIMPII_HUMAN; NP_005497.1) (Calvo et al., 1995), and the human CD36 platelet glycoprotein IV (CD36_HUMAN; P16671) (Oquendo et al., 1989). Amino acids, similar among all sequences, are in black boxes and those conserved in at least two sequences are in shaded boxes. The amino acid residues, characteristic for conserved domain `block A' ({-A-}) and the transmembrane region ([TM]) as well as those which represent the internal potential N-linked glycosylation sites, are marked. (B) Phylogenetic tree constructed from the above mentioned sponge sequence and the two human sequences together with the epithelial membrane protein CG2727-PA from Drosophila melanogaster (EMP-CG_DROME; NP_523859.2), the CD36 family member from Caenorhabditis elegans (CD36_CAEEL; NP_499625.1), Spo71p sequence from Saccharomyces cerevisiae (Spo71p_YEAST; NP_010389.1) (Jacq et al., 1997) and the fructose-bisphosphatase precursor protein At3g54050.1 from Arabidopsis thaliana (FBPPP_ARATH; NP_190973.1). After alignment the tree was built and rooted using the plant sequence as an outgroup. Scale bar indicates an evolutionary distance of 0.1 amino acid substitutions per position in the sequence. (C) Comparison of the S. domuncula CD36/LIMPII receptor molecule with the related human sequences: the lysosomal integral membrane protein II (LIMPII_HUMAN), membrane glycoprotein CLA-1 protein (CLA-1_HUMAN; A48528) (Calvo et al., 1993) and CD36 (CD36_HUMAN). A phylogenetic cladogram (slanted), was constructed and, after alignment, rooted with the sponge CD36/LIMPII receptor. The analysis was performed by neighbor-joining as described under Materials and Methods. The numbers at the nodes are an indication of the level of confidence–given as a percentage–for the branches as determined by bootstrap analysis [1000 bootstrap replicates]. Note: The cDNA sequences from Suberites domuncula have been deposited in EMBL/GenBank databases; cDNA for the CD36/LIMPII receptor is under the accession number AJ558195.