Identification and functional characterization of proteins involved in coccolith biogenesis in Emiliania huxleyi
Final Report Abstract
One of the most spectacular example of biomineralization are the calcitic scales of single-celled algae known as coccolithophores. These scales, called coccoliths, are complex 3D arrays of convoluted calcite (CaCO3) crystals and produced under genetic control. The molecular machinery and molecular processes underlying coccolith formation remain largely elusive. Understanding coccolith formation at the molecular level is of interest to various fields of research, ranging from paleoceanography over marine geochemistry to materials science research. This research project aimed at improving our understanding of intracellular coccolith biogenesis using the model coccolithophores Emiliania huxleyi and Pleurochrysis carterae. To this end several new experimental approaches were developed. An important breakthrough was the discovery of a calcium-storage organelle in E. huxleyi and P. carterae which seems to supply coccolith formation with calcium. The new organelle provides a fresh entry point into the investigation of not only the chemical pathways underlying calcification in coccolithophores but also how calcification is connected to other metabolic processes. The corresponding press release was printed by several public newspapers. A second breakthrough was the discovery of a mechanism that directs mineralization to the sites the calcite crystals are destined to form. This finding and the underlying experimental approach provide a fresh entry point for the elucidation of coccolith morphogenesis. Also this breakthrough was discussed in the public press. In addition to both breakthroughs, several new proteins were identified that may play a role in coccolith formation in E. huxleyi. Clarifying these roles will require further investigations.
Publications
- (2018) Exploiting algal mineralization for nanotechnology: bringing coccoliths to the fore. Current opinion in biotechnology 49 57–63
Skeffington, Alastair W., André Scheffel
(See online at https://doi.org/10.1016/j.copbio.2017.07.013) - (2013) Gas-Chromatography Mass-Spectrometry (GC-MS) based metabolite profiling reveals mannitol as a major storage carbohydrate in the coccolithophorid alga Emiliania huxleyi. Metabolites 3: 168-184
Obata T., Schoenefeld S., Krahnert I., Bergmann S., Scheffel A. and Fernie A.
(See online at https://dx.doi.org/10.3390/metabo3010168) - (2016) A vacuole-like compartment concentrates a disordered calcium phase in a key coccolithophorid alga. Nat. Commun. 7: 11228
Sviben S., Gal A., Hood M.A., Bertinetti L., Politi Y., Bennet M., Krishnamoorthy P., Schertel A., Wirth R., Sorrentino A., Pereiro E., Faivre D. and Scheffel A.
(See online at https://doi.org/10.1038/ncomms11228) - (2016) Control of biogenic nanocrystal formation in biomineralization. Israel Journal of Chemistry 56: 227-241
Addadi, L., Gal, A., Faivre, D., Scheffel, A. and Weiner, S.
- (2016) Lattice distortions in coccolith calcite crystals originate from occlusion of biomacromolecules. J. Struct. Biol. 196: 147-154
Hood M.A., Leemreize H., Scheffel A. and Faivre D.
(See online at https://doi.org/10.1016/j.jsb.2016.09.010) - (2016) Macromolecular recognition directs calcium ions to coccolith mineralization sites. Science 353: 590-593
Gal A., Wirth R., Kopka J., Fratzl P., Faivre D. and Scheffel A.
(See online at https://doi.org/10.1126/science.aaf7889) - (2017) Templated and self-limiting calcite formation directed by coccolith organic macromolecules. Chem. Commun., 53: 7740-774
Gal A., Wirth R., Barkay Z., Eliaz N., Scheffel A. and Faivre D.
(See online at https://doi.org/10.1039/c7cc03639f) - (2017) Trace-element incorporation into intracellular pools uncovers calcium-pathways in a coccolithophore. Adv. Sci.
Gal A., Sviben S., Wirth R., Schreiber A., Lassalle-Kaiser B., Faivre D. and Scheffel A.
(See online at https://doi.org/10.1002/advs.201700088)
