Kurzfassung

Siliceous sponges have the amazing ability to form highly ordered skeletons of amorphous silica. The synthesis of the structural elements, the spicules is under genetic control. The proposed research builds on the outcome from the first funding period during which we identified and cloned from the marine sponge Suberites domuncula a) silicatein-β, an isoform of silicatein-α which forms silica from monosilicic acid in solution, b) the first enzyme, silicase, able to promote dissolution...Siliceous sponges have the amazing ability to form highly ordered skeletons of amorphous silica. The synthesis of the structural elements, the spicules is under genetic control. The proposed research builds on the outcome from the first funding period during which we identified and cloned from the marine sponge Suberites domuncula a) silicatein-β, an isoform of silicatein-α which forms silica from monosilicic acid in solution, b) the first enzyme, silicase, able to promote dissolution (degradation) of amorphous silica, and c) the first silicon transporter, NBCSA cotransporter, from a metazoan (sponge) organism. The aim of this project is to prove the function and elucidate the mechanism of these enzymes/proteins in biosilicification using different models and techniques. We will investigate a) posttranslational modification(s) of silicateins possibly responsible for the lower activity of the recombinant enzymes (application of proteomics approaches) and b) the dynamics of the (differential) expression of the enzymes [silicateins, silicase] and proteins [silicon transporter] (use of primmorphs as a model for spiculogenesis; in situ hybridization studies), and provide evidence for their function by expression in heterologous systems which are not able to mineralize or to transport silicic acid (microinjection of the transporter mRNA or protein into frog oocytes).» weiterlesen» einklappen