The spatial network of skeletal proteins in a stony coral

Coral skeletons are materials composed of inorganic aragonitic fibers, proteins, sugars and lipids that are highly organized to form a solid body upon which the animals live. The skeleton contains more than 30 proteins, all of which are encoded in the animal genome and secreted during the biomineralization process. How these proteins are spatially related is unknown. Using a combination of chemical crosslinking and high-resolution tandem mass spectrometry, we identify, for the first time. the spatial interactions of the skeletal proteins within a stony coral. Our subsequent network analysis revealed several coral acid-rich proteins (CARPs) are invariably associated with carbonic anhydrase(s), alpha-collagen, cadherins and other calcium binding proteins. These interactions clearly show that protein-protein interactions in coral skeletons are highly coordinated and are key to understanding the formation and persistence of coral skeletons through time

珊瑚骨骼是由无机文石纤维、蛋白质、糖类与脂质构成的材料，这些组分高度有序地组装形成珊瑚虫栖息的固体基质。该骨骼包含三十余种蛋白质，所有蛋白均由该动物的基因组编码，并在生物矿化过程中分泌。目前学界尚未明确这些蛋白质的空间关联方式。本研究结合化学交联与高分辨率串联质谱技术，首次鉴定出石珊瑚体内骨骼蛋白质的空间相互作用。后续的网络分析显示，多种富酸珊瑚蛋白（coral acid-rich proteins, CARPs）始终与碳酸酐酶、α-胶原蛋白、钙粘蛋白及其他钙结合蛋白存在关联。这些相互作用清晰表明，珊瑚骨骼内的蛋白质间相互作用具有高度协调性，这是理解珊瑚骨骼随时间形成与存续的关键所在。