Evolution of the thioester-containing proteins (TEPs) of the arthropoda, revealed by molecular cloning of TEP genes from a spider, Hasarius adansoni

Evolution of the Complement System

“…Phylogenetic analysis of many TEP superfamily genes from various eumetazoa indicated the presence of two dichotomous families, C3 and A2M ( Fig. 3.1), and this classification was supported by the presence of the ANA (anaphylatoxin) and C345C domains in all members of the C3 family, but never in the A2M family members [6]. The C3 family comprises human C3, C4, C5 and their orthologs of various eumetazoa, whereas the A2M family comprises human A2M, PZP, CD109, CPAMD8 and their orthologs.…”

“…All deuterostome species analyzed thus far such as various vertebrates, urochordate sea squirt [13], cephalochordate lancelet and echinoderm sea urchin [2], possess both the C3 and A2M family members, whereas many protostome genomes deciphered thus far such as fly [14], mosquito [15], honeybee [16], parasitoid wasp [17], aphid [18], flour beetle [19], and Caenorhabditis elegans [20] possessed only the A2M family members. Among protostomes, only horseshoe crab [21,22], spider [6], tick [23], clam [24] and squid [25] were reported to possess the C3 family, indicating that the loss of the C3 family has occurred multiple times during the protostome evolution [6]. The loss of the C3 family also occurred at least once in cnidaria, since hydra has only the A2M family gene [26].…”

“…The C3 family comprises human C3, C4, C5 and their orthologs of various eumetazoa, whereas the A2M family comprises human A2M, PZP, CD109, CPAMD8 and their orthologs. Accumulation of sequence information concerning various eumetazoa TEPs indicated that the iTEP (insect TEP) once considered unique to insects or arthropods is in fact orthologous to CD109 [6]. A2M, PZP and CPAMD8 are close to each other, and the A2M family is further subdivided into the A2M subfamily and the CD109 subfamily.…”

Evolution of the complement system in protostomes revealed by de novo transcriptome analysis of six species of Arthropoda

“…Although the C3 gene has been identified from all deuterostome species analyzed thus far (Nonaka, 2014), earlier genomic analyses showed its absence from the genomes of Drosophila melanogaster (Adams et al, 2000) and Caenorhabditis elegans (C. elegans Sequencing Consortium, 1998), indicating that this gene has been lost in at least some lineages of protostomes. On the other hand, the C3 gene has been reported from several other protostome species, such as the clam (Prado-Alvarez et al, 2009), the squid (Castillo et al, 2009), horseshoe crabs (Ariki et al, 2008;Zhu et al, 2005), the spider (Sekiguchi et al, 2012) and ticks (Buresova et al, 2011;Urbanová et al, 2015), and FB has also been reported from the clam (Prado-Alvarez et al, 2009) and horseshoe crab (Tagawa et al, 2012;Zhu et al, 2005). However, to date, no comprehensive analysis of the complement genes has been performed in protostome species possessing the C3 gene and it is still an unsolved question as to whether the protostome complement system shares complement components other than C3 and FB with deuterostomes.…”

“…In addition, insect TEP (iTEP) (Blandin and Levashina, 2004) has been reported from the fly and mosquito, which lack C3 and A2M, and certain iTEPs show opsonic activity similar to C3 (Levashina et al, 2001), suggesting that insects compensate for the loss of the complement system by expanding the functions of iTEPs. Later, iTEP was shown to be orthologous to CD109 by extensive phylogenetic analysis (Sekiguchi et al, 2012). Macroglobulin complement-related (Mcr) found from D. melanogaster shows overall structural similarity to these TEP family members, although it lacks the thioester site and possesses low density lipoprotein receptor class A (LDLa) domain not found in C3, A2M or CD109/iTEP (Stroschein-Stevenson et al, 2006).…”