Intracellular morphogenesis of diatom silica is guided by local variations in membrane curvature

DOI: 10.1038/s41467-024-52211-x

Authors: Lior Aram (Weizmann Institute of Science) , Diede De Haan (Weizmann Institute of Science) , Neta Varsano (Weizmann Institute of Science) , James B. Gilchrist (Diamond Light Source) , Christoph Heintze (Technische Universität Dresden) , Ron Rotkopf (Weizmann Institute of Science) , Katya Rechav (Weizmann Institute of Science) , Nadav Elad (Weizmann Institute of Science) , Nils Kröger (Technische Universität Dresden) , Assaf Gal (Weizmann Institute of Science)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 15

State: Published (Approved)
Published: September 2024
Diamond Proposal Number(s): 29609

Abstract: Silica cell-wall formation in diatoms is a showcase for the ability of organisms to control inorganic mineralization. The process of silicification by these unicellular algae is tightly regulated within a membrane-bound organelle, the silica deposition vesicle (SDV). Two opposing scenarios were proposed to explain the tight regulation of this intracellular process: a template-mediated process that relies on preformed scaffolds, or a template-independent self-assembly process. The present work points to a third scenario, where the SDV membrane is a dynamic mold that shapes the forming silica. We use in-cell cryo-electron tomography to visualize the silicification process in situ, in its native-state, and with a nanometer-scale resolution. This reveals that the plasma membrane interacts with the SDV membrane via physical tethering at membrane contact sites, where the curvature of the tethered side of the SDV membrane mirrors the intricate silica topography. We propose that silica growth and morphogenesis result from the biophysical properties of the SDV and plasma membranes.

Diamond Keywords: Biomineralisation

Subject Areas: Biology and Bio-materials, Chemistry

Diamond Offline Facilities: Electron Bio-Imaging Centre (eBIC)
Instruments: Krios IV-Titan Krios IV at Diamond , Scios-Scios at Diamond

Added On: 12/09/2024 10:30

Documents:
s41467-024-52211-x.pdf

Discipline Tags:

Biochemistry Chemistry Structural biology Biophysics Life Sciences & Biotech

Technical Tags:

Microscopy Electron Microscopy (EM) Cryo Electron Microscopy (Cryo EM)