title: Highly conserved caspase and Bcl-2 homologues from the sea anemone Aiptasia pallida: lower metazoans as models for the study of apoptosis evolution.
abstract: Key insight into the complexities of apoptosis may be gained from the study of its evolution in lower metazoans. In this study we describe two genes from a cnidarian, Aiptasia pallida, that are homologous to key genes in the apoptotic pathway from vertebrates. The first is a novel ancient caspase, acasp, that displays attributes of both initiator and executioner caspases and includes a caspase recruitment domain (CARD). The second, a Bcl-2 family member, abhp, contains a BH1 and BH2 domain and shares structural characteristics and phylogenetic affinity with a group of antiapoptotic Bcl-2s including A1 and Bcl-2L10. The breadth of occurrence of other invertebrate homologues across the phylogenetic trees of both genes suggests that the complexity of apoptotic pathways is an ancient trait that predates the evolution of vertebrates and higher invertebrates such as nematodes and flies. This paves the way for establishing new lower metazoan model systems for the study of apoptosis.
authors.affiliation: Department of Zoology, Oregon State University, Corvallis, OR 97331, USA. dunns@science.oregonstate.edu
authors.forename: Simon R
authors.initials: SR
authors.lastname: Dunn
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Phillips
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Spatafora
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Green
authors.forename: Virginia M
authors.initials: VM
authors.lastname: Weis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D001483:Base Sequence; D005075:Biological Evolution; D020169:Caspases / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D019254:Genes, bcl-2; D023421:Models, Animal; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012615:Sea Anemones / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D020169:Caspases