Molecular characterization of a new leucine-rich repeat-containing G protein-coupled receptor from a bivalve mollusc: evolutionary implications.
The family of leucine-rich repeat-containing G protein-coupled receptors (LGRs) shows members in both vertebrates and invertebrates including the most ancestral ones. Although this suggests an early evolutionary origin of this family of receptors, little is known about their diversity in molluscs, a major phylum of bilaterian invertebrates. Based on sequences of mammalian and insect LGRs, we have cloned and characterized a new typical LGR in the bivalve mollusc Crassostrea gigas. This receptor named Cg-LGRB exhibits high degree of amino acid sequence identity with both mammalian and Drosophila LGRs. Phylogenetic analysis indicates that Cg-LGRB belongs to the cluster of type B orphan LGRs and suggests that molluscs likely express the three LGR subgroups identified previously in other animals. Quantitative RT-PCR shows that Cg-LGRB is expressed mainly in the digestive gland and only at moderate levels in other organs and developmental stages. A possible involvement in the control of cytological changes occurring in bivalve mollusc digestive gland is discussed.
Herpin
Amaury
A
Laboratoire de Biologie et Biotechnologies Marines, IBFA, UMR IFREMER-Université de Caen, Physiologie et Ecophysiologie des Mollusques Marins, Esplanade de la Paix, 14032 Caen Cedex, France.
Badariotti
Fabien
F
Rodet
Frank
F
Favrel
Pascal
P
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D004064:Digestive System / Q000378:metabolism; D007930:Leucine / Q000737:chemistry; D000090263:Leucine-Rich Repeat Proteins; D008969:Molecular Sequence Data; D008974:Mollusca / Q000737:chemistry*; D010802:Phylogeny; D011506:Proteins / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; D043562:Receptors, G-Protein-Coupled; D007930:Leucine