Single-Cell Biophysics: Measurement, Modulation, and Modeling

Single-Cell Biophysics: Measurement, Modulation, and Modeling

Poster Abstracts

78-POS Board 39 Superresolution Imaging Reveals Protein-Templated Patterns for Biosilica Formation Philip Gröger 1 , Nicole Poulsen 1 , Jennifer Klemm 1 , Nils Kröger 1,2 , Michael Schlierf 1 . 1 TU Dresden, Dresden, Germany, 2 TU Dresden, Dresden, Germany. The intricate, genetically controlled biosilica nano- and micropatterns produced by diatoms are a testimony for biology’s ability to control mineral formation (biomineralization) at the nanoscale and regarded as paradigm for nanotechnology. Several recently discovered protein families involved in diatom biosilica formation remain tightly associated with the final biosilica structure. Determining the locations of biosilica-associated proteins with high precision is therefore expected to provide clues to their roles in biosilica morphogenesis. To achieve this, we introduce single-molecule localization microscopy to diatoms based on photo-activated light microscopy (PALM) to overcome the diffraction limit. We identified six photo-convertible fluorescent proteins (FPs) that can be utilized for PALM in the cytoplasm of Thalassiosira pseudonana. However, only three FPs that share a common molecular conversion-mechanism were also functional when embedded in diatom biosilica and localized with a mean precision of 25 nm to resolve structural features. Further co-localization studies on proteins of the Cingulin family when extracted from the biosilica using a combined two-color PALM+STORM approach revealed characteristic protein filaments with distinct protein specific patterns. The enhanced microscopy techniques introduced here for diatoms will aid in elucidating the molecular mechanism of silica biomineralization as well as other aspects of diatom cell biology.

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