Identification of a novel aminergic-like G protein-coupled receptor in the cnidarian Renilla koellikeri

Genes encoding putative biogenic amine receptors in the parasitic nematode Brugia malayi

“…At the present time, it is not possible to resolve from the tree whether any extant receptor is most closely related to a hypothetical ancestral GPCR progenitor gene. A single aminergic receptor (RkD1) from the basal cnidarian Renilla koellikeri is known but this appears most closely related to Ce-Gar-1 and CbP01300 in the IIA subclade (Bouchard et al 2004). The sequencing of more GPCRs from more acoelomates and cnidarians may help to resolve this issue but in the absence of such data the phylogenetic origin of extant BARs remains uncertain.…”

Sequence and expression of four coral G protein-coupled receptors distinct from all classifiable members of the rhodopsin family

“…While they possess nearly all the defining residues of the rhodopsin family of GPCRs, the DRY motif at the TMIII/I2 transition and the cysteine residues bridging TMIII and E2 are not conserved in the A. millepora receptors. These discrepancies are shared with Ren2 of the sea pansy (Bouchard et al, 2004). The DRF and DRL motifs of the coral, as well as the DRC motif of Ren2, have in common that tyrosine is substituted by hydrophobic residues.…”

“…They add to the four GPCRs previously cloned from other cnidarians, two from sea anemones (Nothacker and Grimmelikhuijzen, 1993;New et al, 2000), and two others from the sea pansy (Bouchard et al, 2003(Bouchard et al, , 2004.…”

“…appeared to be orphan, with no clear relationship with any known GPCR rhodopsin subfamilies (New et al, 2000). More recently two GPCRs showing strong similarity to aminergic receptors were identified in the sea pansy Renilla koellikeri (Bouchard et al, 2003(Bouchard et al, , 2004. No ligand has been identified for any of these receptors despite extensive screening of heterologously expressed transcripts in the case of the sea pansy GPCRs (Bouchard et al, 2003(Bouchard et al, , 2004.…”

Hormonal signaling in cnidarians: do we understand the pathways well enough to know whether they are being disrupted?

“…Also, genes for G protein-coupled receptors have been cloned (Nothacker and Grimmelikhuijzen, 1993;New et al, 2000;Bouchard et al, 2003), but the ligands for these receptors have not yet been identified. One G protein-coupled receptor is phylogenetically related to dopamine and adrenergic receptors but not responsive to known biogenic amines (Bouchard et al, 2003;Bouchard et al, 2004).…”