Quantitative Phosphoproteomics of whole-body sponge collapse

Sponges (Porifera) are early-branching Metazoa who do not possess muscles or neurons, however are able to undergo a whole-body movement that involves the closure of their canal system and collapse of an epithelial tent. In this study we profile the proteomic responses of the freshwater sponge Spongilla lacustris during nitric oxide (NO) and agitation induced movements to elucidate the early evolution of coordination in animals. Specifically, we used tandem mass tag (TMT) labeling-based quantification of enriched phosphopeptides to systematically measure quantitative differences in protein phosphorylation. We identified and quantified 12165 unique phosphopeptides in the sponge. NO treatment resulted in quantitative changes of phosphorylation levels on 390 unique phosphopeptides mapping to 270 unique proteins. In turn, agitation led to quantitative changes of phosphorylation levels on 303 unique phosphopeptides (229 proteins).