Structural and functional characterizations of an Activin type II receptor orthologue from the pacific oyster Crassostrea gigas.
Members of the Transforming Growth factor beta (TGF-beta) superfamily of cell signalling polypeptides are known to play important roles in cell proliferation and differentiation during development and in various physiological processes of most animal clades. Recent findings in the mollusc Crassostrea gigas demonstrate the occurrence of a diversity of TGF-beta signalling components including various ligands, three type I receptors but only a single type II receptor. This report describes the characterization of Cg-ActRII, a new type II receptor displaying homology with vertebrate and Drosophila Activin type II receptors. The use of zebrafish embryo as a reporter organism revealed that, in a way similar to its zebrafish counterpart, overexpression of Cg-ActRII or its dominant negative acting truncated form resulted in a dose dependent range of dorsoventral defects coupled with anterior disorders. Expression pattern of Cg-ActRII transcripts examined by real time PCR and in situ PCR in C. gigas showed high levels of Cg-ActRII transcripts in early embryonic stages and in the developing larval central nervous system. Except for a high expression in the visceral ganglia, most oyster adult tissues displayed rather low levels of transcripts. Altogether, the data suggest a high degree of conservation at both the structural and functional levels during evolution for this class of receptors.
Le Quéré
Hervé
H
UMR M100 IFREMER, Université de Caen Basse-Normandie, Physiologie et Ecophysiologie des Mollusques Marins, IBFA, IFR 146 ICORE, Esplanade de la Paix, Caen Cedex, France.
Herpin
Amaury
A
Huvet
Arnaud
A
Lelong
Christophe
C
Favrel
Pascal
P
D030301:Activin Receptors, Type II / Q000145:classification / Q000235:genetics* / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D049896:Crassostrea / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D007814:Larva / Q000235:genetics / Q000254:growth & development; D008297:Male; D008845:Microinjections; D008969:Molecular Sequence Data; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish
D030301:Activin Receptors, Type II