Structural and functional analyses of calcium ion response factors in the mantle of Pinctada fucata

Publication date: Available online 17 August 2018Source: Journal of Structural BiologyAuthor(s): Akihiro Matsuura, Ko Yoshimura, Hiroyuki Kintsu, Takashi Atsumi, Yasushi Tsuchihashi, Takeshi Takeuchi, Noriyuki Satoh, Lumi Negishi, Shohei Sakuda, Tomiko Asakura, Yuki Imura, Etsuro Yoshimura, Michio SuzukiAbstractThe pearl oyster, Pinctada fucata, is cultured for pearl production in Japan. The shell of the pearl oyster consists of calcium carbonate and a small amount of organic matrix. Despite many studies of the shell matrix proteins, the mechanism by which calcium elements are transported from the mantle to the shell remains unclear. Investigating the molecular mechanism of calcium transportation, we prepared artificial seawater with a high concentration of calcium ions (10ASW) to induce calcification in the pearl oyster. When pearl oysters were cultured in 10ASW, unusual nanoparticles were precipitated on the surface of the nacreous layer. SDS-PAGE and 2D-PAGE analyses revealed that some calcium-sensing proteins (Sarcoplasmic Ca-binding Protein (Pf-SCP) and Pf-filamin A) might be related to the synthesis of these nanoparticles. The recombinant proteins of Pf-SCP can bind to calcium ions and accumulate nanoparticles of calcium carbonate crystals. However, transcriptomic analysis of the pearl oysters grown in 10ASW showed that the matrix protein genes in the shell did not differ before and after treatment with 10ASW. These results suggest that, despite increasing calcium trans...
Source: Journal of Structural Biology - Category: Biology Source Type: research