TY - JOUR T1 - Optimization of skeletal protein preparation for LC-MS/MS sequencing yields additional coral skeletal proteins in <em>Stylophora pistillata</em> JF - bioRxiv DO - 10.1101/2020.03.16.991273 SP - 2020.03.16.991273 AU - Yanai Peled AU - Jeana Drake AU - Assaf Malik AU - Ricardo Almuly AU - Maya Lalzar AU - David Morgenstern AU - Tali Mass Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/05/21/2020.03.16.991273.abstract N2 - Stony corals generate their calcium carbonate exoskeleton in a highly controlled biomineralization process mediated by a variety of macromolecules including proteins. Fully identifying and classifying these proteins is crucial to understanding their role in exoskeleton formation, yet no optimal method to purify and characterize the full suite of extracted coral skeletal proteins has been established and hence their complete composition remains obscure. Here, we tested four skeletal protein purification protocols using acetone precipitation and ultrafiltration dialysis filters to present a comprehensive scleractinian coral skeletal proteome. We identified a total of 60 proteins in the coral skeleton, 44 of which were not present in previously published stony coral skeletal proteomes. Extracted protein purification protocols carried out in this study revealed that no one method captures all proteins and each protocol revealed a unique set of method-exclusive proteins. To better understand the general mechanism of skeletal protein transportation, we further examined the proteins’ gene ontology, transmembrane domains, and signal peptides. We found that transmembrane domain proteins and signal peptide secretion pathways, by themselves, could not explain the transportation of proteins to the skeleton. We therefore propose that some proteins are transported to the skeleton via non-traditional secretion pathways.Competing Interest StatementThe authors have declared no competing interest.(ACT)acetone precipitation of proteins(CF)centrifugation ultrafiltration of proteins(FDR)false discovery rate(GO)gene ontology(GPI)glycosylphosphatidylinositol(ISOM)insoluble skeletal organic matrix(PSM)peptide spectra matches(PBS)phosphate buffered saline(SOM)skeletal organic matrix(SOMP)skeletal organic matrix proteins(SSOM)soluble skeletal organic matrix(TM)transmembrane ER -