Functional conservation of the apoptotic machinery from coral to man: the diverse and complex Bcl-2 and caspase repertoires of Acropora millepora

BMC Genomics

Research Article

Aurelie Moya¹  David J. Miller²  Yvonne Weiss²  Benjamin M. Mason²  Sylvain Forêt³  Eldon E. Ball³  Lotte Huisman⁴  Kentaro Tomii⁵  Kenichiro Imai⁵  Tara E. Bull⁶  Kazuhiro Sakamaki⁷  David C. Hayward⁸ 

[1] ARC Centre of Excellence for Coral Reef Studies, James Cook University, 4811, Townsville, Queensland, Australia;ARC Centre of Excellence for Coral Reef Studies, James Cook University, 4811, Townsville, Queensland, Australia;Comparative Genomics Centre and Department of Molecular and Cell Biology, James Cook University, 4811, Townsville, Queensland, Australia;ARC Centre of Excellence for Coral Reef Studies, James Cook University, 4811, Townsville, Queensland, Australia;Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Bldg. 46, 0200, Canberra, ACT, Australia;ARC Centre of Excellence for Coral Reef Studies, James Cook University, 4811, Townsville, Queensland, Australia;Section of Computational Science, Universiteit van Amsterdam, Science Park 904, 1098, Amsterdam, XH, The Netherlands;Biotechnology Research Institute for Drug Discovery, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology (AIST), 135-0064, Tokyo, Japan;Comparative Genomics Centre and Department of Molecular and Cell Biology, James Cook University, 4811, Townsville, Queensland, Australia;Department of Animal Development and Physiology, Graduate School of Biostudies, Kyoto University, 606-8501, Kyoto, Japan;Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Bldg. 46, 0200, Canberra, ACT, Australia;

关键词: Apoptosis;    Caspase;    Bcl-2;    Coral;    Acropora millepora;    Cnidaria;   

DOI  :  10.1186/s12864-015-2355-x

 received in 2015-07-08, accepted in 2015-12-21,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundApoptotic cell death is a defining and ubiquitous characteristic of metazoans, but its evolutionary origins are unclear. Although Caenorhabditis and Drosophila played key roles in establishing the molecular bases of apoptosis, it is now clear that cell death pathways of these animals do not reflect ancestral characteristics. Conversely, recent work suggests that the apoptotic networks of cnidarians may be complex and vertebrate-like, hence characterization of the apoptotic complement of representatives of the basal cnidarian class Anthozoa will help us to understand the evolution of the vertebrate apoptotic network.ResultsWe describe the Bcl-2 and caspase protein repertoires of the coral Acropora millepora, making use of the comprehensive transcriptomic data available for this species. Molecular phylogenetics indicates that some Acropora proteins are orthologs of specific mammalian pro-apoptotic Bcl-2 family members, but the relationships of other Bcl-2 and caspases are unclear. The pro- or anti-apoptotic activities of coral Bcl-2 proteins were investigated by expression in mammalian cells, and the results imply functional conservation of the effector/anti-apoptotic machinery despite limited sequence conservation in the anti-apoptotic Bcl-2 proteins. A novel caspase type (“Caspase-X”), containing both inactive and active caspase domains, was identified in Acropora and appears to be restricted to corals. When expressed in mammalian cells, full-length caspase-X caused loss of viability, and a truncated version containing only the active domain was more effective in inducing cell death, suggesting that the inactive domain might modulate activity in the full-length protein. Structure prediction suggests that the active and inactive caspase domains in caspase-X are likely to interact, resulting in a structure resembling that of the active domain in procaspase-8 and the inactive caspase domain in the mammalian c-FLIP anti-apoptotic factor.ConclusionsThe data presented here confirm that many of the basic mechanisms involved in both the intrinsic and extrinsic apoptotic pathways were in place in the common ancestor of cnidarians and bilaterians. With the identification of most or all of the repertoires of coral Bcl-2 and caspases, our results not only provide new perspectives on the evolution of apoptotic pathways, but also a framework for future experimental studies towards a complete understanding of coral bleaching mechanisms, in which apoptotic cell death might be involved.

【 授权许可】

CC BY   
© Moya et al. 2016