Membrane labeling of coral gastrodermal cells by biotinylation: the proteomic identification of surface proteins involving cnidaria-dinoflagellate endosymbiosis

• Published in: PloS one Vol. 9; no. 1; p. e85119
• Main Authors: Li, Hsing-Hui, Huang, Zi-Yu, Ye, Shih-Png, Lu, Chi-Yu, Cheng, Pai-Chiao, Chen, Shu-Hwa, Chen, Chii-Shiarng
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 07.01.2014; Public Library of Science (PLoS)
• Subjects: Animals; Anthozoa - parasitology; Anthozoa - physiology; Aquariums; Biochemistry; Biology; Biotechnology; Biotin; Biotinylation; Cell Membrane - metabolism; Cell surface; Chromatography; Cytoskeleton; Dinoflagellates; Dinoflagellida - physiology; Energy metabolism; Euphyllia glabrescens; Fluorescence; Fluorescence microscopy; Gel electrophoresis; Gene expression; Genomes; Heat; Liquid chromatography; Marine biology; Mass spectrometry; Mass spectroscopy; Membrane Proteins - metabolism; Membranes; Metabolism; Microorganisms; Museums; Nuclear power plants; Physiological aspects; Plasma; Protein binding; Proteins; Proteome - metabolism; Proteomics - methods; Seawater; Staining and Labeling; Streptavidin; Stress response; Symbiodinium; Symbiosis; Taiwan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0085119

The cellular and molecular-scale processes underlying the stability of coral-Symbiodinium endosymbioses remain unclear despite decades of investigation. As the coral gastroderm is the only tissue layer characterized by this unique symbiotic association, the membranes of these symbiotic gastrodermal cells (SGCs) may play important roles in the initiation and maintenance of the endosymbiosis. In order to elucidate the interactions between the endosymbiotic dinoflagellates and their coral hosts, a thorough characterization of SGC membranes is therefore required. Cell surface proteins of isolated SGCs were biotinylated herein by a cell impermeant agent, biotin-XX sulfosuccinimidyl ester. The in situ distribution of these biotinylated proteins was uncovered by both fluorescence and transmission electron microscopic imaging of proteins bound to Alexa Fluor® 488-conjugated streptavidin. The identity of these proteins was then determined by two-dimensional gel electrophoresis followed by liquid chromatography-tandem mass spectrometry. Nineteen (19) proteins were identified, and they are known to be involved in the molecular chaperone/stress response, cytoskeletal remodeling, and energy metabolism. These results not only reveal the molecular characters of the host SGC membrane, but also provide critical insight into understanding the possible role of host membranes in this ecologically important endosymbiotic association.