Meeting Abstract
Caspases belong to a class of cysteinyl proteases that play an integral part in cell development and apoptotic cell death as an evolutionarily conserved function. Apoptotic cell death is a defining characteristic of metazoans; however, the number of caspases identified is distinct for each species and extends back to more than 430 million years. Although the use of C. elegans and D. melanogaster as model organisms have provided key insights in establishing the molecular basis of apoptosis, the disparate cell death pathways have obscured its evolutionary origins. Reef-building corals of the Phylum Cnidaria are an emerging model for caspase studies. Research suggests that Cnidarian apoptotic pathways may be similar to and as complex as vertebrate pathways. Recent findings suggest that corals characterized as disease-susceptible undergo an apoptotic response, whereas tolerant species exhibit an autophagic response. Caspases have developed overlapping substrate profiles and common and unique allosteric sites for fine-tuning caspase activity, through hundreds of millions of years of evolution and are therefore an excellent model system for studying protein evolution. Comparison of the caspase repertoire of these corals lying on the opposing ends of the immunity spectrum will provide advanced knowledge in the fields of protein evolution, controlled cell death and coral biology. Protein folding studies on the reconstructed ancestral proteins between humans and invertebrate species will provide insights into the molecular and biophysical mechanisms that mediate caspase function and evolution. These studies aim to test the central underlying hypothesis, that, differences in the evolution of caspase activity, substrate specificity and allosteric regulation underlie the ecological trajectories of each coral species.
