Abstract

Many complex biological functions are performed by supramolecular assemblies selforganized from a diverse ensemble of proteins. The spatial organizations of protein building blocks within these structures are key to their functions, but have been challenging to determine experimentally. Due to the nanometer size scale of proteins, the nanoscale is the salient length scale for structural organization in cells. Thanks to the recent development of superresolution microscopy, it has become possible to decipher the intricate nanoscale architecture of several cellular structures. For these structural cell biology applications, high spatial resolution, ideally approaching the sub-10 nm scale of protein-size is desirable. Interference-based strategies have been particularly useful for achieving such molecular-scale resolution[1-4]. I will discuss examples of interference-based techniques in superresolution microscopy and their applications to decipher nanoscale organization of cell adhesions machinery. Of particular biological relevance, cell adhesions such as the cadherin-mediated cell-cell junctions are multi-protein assemblies known to transmit, sustain, sense, and respond to mechanical force. The knowledge of their physical organization is therefore essential for molecular mechanistic insights into their mechanobiological functions. I will discuss our recent study whereby interference-based superresolution strategy was employed to elucidate the nanoscale architecture of the cadherin-based cell adhesions and to probe conformational transitions of the mechanotransducer protein vinculin, revealing how they are regulated by mechanical tension together with specific tyrosine kinase and phosphatase [4].

© 2017 Japan Society of Applied Physics, Optical Society of America