Silicanin-1 is a conserved diatom membrane protein involved in silica biomineralization

BMC Biology

Research Article

Philip Gröger¹  Alexander Kotzsch¹  Michael Schlierf¹  Damian Pawolski¹  Nils Kröger²  Paul H. H. Bomans³  Nico A. J. M. Sommerdijk³ 

[1] B CUBE Center for Molecular Bioengineering, CMCB, TU Dresden, Arnoldstrasse 18, 01307, Dresden, Germany;B CUBE Center for Molecular Bioengineering, CMCB, TU Dresden, Arnoldstrasse 18, 01307, Dresden, Germany;Department of Chemistry and Food Chemistry, TU Dresden, 01062, Dresden, Germany;Department of Chemical Engineering and Chemistry, Laboratory of Materials and Interface Chemistry & Center of Multiscale Electron Microscopy, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands;Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands;

关键词: Diatom biosilica;    Biomineralization vesicles;    Transmembrane protein;    Vesicle biogenesis;    Exocytosis;    Time-lapse confocal fluorescence microscopy;    Protein self-assembly;    Cryo-TEM;    Silica formation activity;   

DOI  :  10.1186/s12915-017-0400-8

 received in 2017-05-18, accepted in 2017-06-28,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundBiological mineral formation (biomineralization) proceeds in specialized compartments often bounded by a lipid bilayer membrane. Currently, the role of membranes in biomineralization is hardly understood.ResultsInvestigating biomineralization of SiO2 (silica) in diatoms we identified Silicanin-1 (Sin1) as a conserved diatom membrane protein present in silica deposition vesicles (SDVs) of Thalassiosira pseudonana. Fluorescence microscopy of GFP-tagged Sin1 enabled, for the first time, to follow the intracellular locations of a biomineralization protein during silica biogenesis in vivo. The analysis revealed incorporation of the N-terminal domain of Sin1 into the biosilica via association with the organic matrix inside the SDVs. In vitro experiments showed that the recombinant N-terminal domain of Sin1 undergoes pH-triggered assembly into large clusters, and promotes silica formation by synergistic interaction with long-chain polyamines.ConclusionsSin1 is the first identified SDV transmembrane protein, and is highly conserved throughout the diatom realm, which suggests a fundamental role in the biomineralization of diatom silica. Through interaction with long-chain polyamines, Sin1 could serve as a molecular link by which the SDV membrane exerts control on the assembly of biosilica-forming organic matrices in the SDV lumen.

【 授权许可】

CC BY   
© Kröger et al. 2017