However, selleck chemicals at least four distinct dacts could be clearly distinguished. Currently, it is controversial whether cyclostomes and gnathostomes shared the first round of genome duplication, whether an independent genome duplication occurred in the cyclostome lineage, or whether individual genes were duplicated. While most of the phylogenetic trees rather support independent expansions of the Dact family in cyclostomes and gnathostomes, the star like topology shown by quartet puzzling indicates the uncertainty of their relationship. For non vertebrate chordates, we were able to identify a dact gene in the Florida lancelet, but not in any of the tunicates searched. This is remarkable, given that tunicates are thought to be more closely related to vertebrates than cephalochordates.

However, tunicates have reduced their body plan during evolution, and it is possible that they secondarily lost their dact gene. We can speculate that the loss of signaling cascades regulators may have facilitated the reduction of tunicate body structures. The original chordate dact may have served in Wnt signaling Comparing the presence and distribution of functional domains and proteins motifs we found that a number of these, but not all, were shared by Dacts from gnathostomes, cyclostomes and the lancelet, including motifs 1, 2a f, 3c, 4b, 5a c, 8b, 11e f, and the basic aa of the C terminal motif 11 g. Thus, these motifs may represent the original repertoire of the ancestral dact.

Motifs 1 5 occupy the N terminal half of Dact proteins and encompass the leucine zipper essential for homo and heterodimerization, a functionally characterized and a further predicted nuclear export signal, a domain that assists binding to Dvl and a domain that in gnathostome Dact1 has been implicated in Tcf3 binding, and this study. The motifs located in the C terminal half provide a functionally characterized nuclear localization signal and contribute to the Vangl binding domain. All proteins are enriched with serines, particularly in the area containing motifs 2f, 11e. This suggests that already the ancestral dact was a multiadaptor protein, capable of interacting with molecules in the B Catenin dependent and PCP Wnt signaling pathway, possibly able to shuttle between the nucleus and cytoplasm, and subject to extensive regulation by phosphorylation.

In gnathostomes Dacts 1,2,3, motif 11 g contains the MTTV sequence, a PDZ binding domain required for the interaction of Dact with Dvl. This motif was also found in cyclostome dactA, B and D, suggesting that it was a feature of the Dact protein in the last common ancestor of vertebrates. In contrast, the lancelet motif 11 g does not contain a recognizable PDZ binding motif. Thus, either Branchiostoma dact has secondarily lost Entinostat this sequence, or alternatively, this sequence appeared in the vertebrate lineage.