Photoswitchable epothilone‐based microtubule stabilisers allow GFP‐imaging‐compatible, optical control over the microtubule cytoskeleton

Abstract Small molecule inhibitors are prime reagents for studies in microtubule cytoskeleton research, being applicable across a range of biological models and not requiring genetic engineering. However, traditional chemical inhibitors cannot be experimentally applied with spatiotemporal precision suiting the length and time scales inherent to microtubule-dependent cellular processes. We have synthesised photoswitchable paclitaxel-based microtubule stabilisers, whose binding is induced by photoisomerisation to their metastable state. Photoisomerising these reagents in living cells allows optical control over microtubule network integrity and dynamics, cell division and survival, with biological response on the timescale of seconds and spatial precision to the level of individual cells within a population. In primary neurons, they enable regulation of microtubule dynamics resolved to subcellular regions within individual neurites. These azobenzene-based microtubule stabilisers thus enable non-invasive, spatiotemporally precise modulation of the microtubule cytoskeleton in living cells, and promise new possibilities for studying intracellular transport, cell motility, and neuronal physiology.

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A Robust, GFP-Orthogonal Photoswitchable Inhibitor Scaffold Extends Optical Control over the Microtubule Cytoskeleton

Cell Chemical Biology ◽

10.1016/j.chembiol.2020.11.007 ◽

2020 ◽

Author(s):

Li Gao ◽

Joyce C.M. Meiring ◽

Yvonne Kraus ◽

Maximilian Wranik ◽

Tobias Weinert ◽

...

Keyword(s):

Optical Control ◽

Microtubule Cytoskeleton

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Photoswitchable microtubule inhibitors enabling robust, GFP-orthogonal optical control over the tubulin cytoskeleton

10.1101/716233 ◽

2019 ◽

Cited By ~ 1

Author(s):

Li Gao ◽

Yvonne Kraus ◽

Maximilian Wranik ◽

Tobias Weinert ◽

Stefanie D. Pritzl ◽

...

Keyword(s):

High Precision ◽

Microtubule Dynamics ◽

Optical Control ◽

Microtubule Cytoskeleton ◽

Precision Control ◽

Microtubule Inhibitors ◽

Dependent Processes

ABSTRACTHere we present GFP-orthogonal optically controlled reagents for reliable and repetitive in cellulo modulation of microtubule dynamics and its dependent processes. Optically controlled reagents (“photopharmaceuticals”) have developed into powerful tools for high-spatiotemporal-precision control of endogenous biology, with numerous applications in neuroscience, embryology, and cytoskeleton research. However, the restricted chemical domain of photopharmaceutical scaffolds has constrained their properties and range of applications. Styrylbenzothiazoles are an as-yet unexplored scaffold for photopharmaceuticals, which we now rationally design to feature potent photocontrol, switching microtubule cytoskeleton function off and on according to illumination conditions. We show more broadly that this scaffold is exceptionally chemically and biochemically robust as well as substituent-tolerant, and offers particular advantages for intracellular biology through a range of desirable photopharmaceutical and drug-like properties not accessible to the current classes of photoswitches. We expect that these reagents will find powerful applications enabling robust, high precision, optically controlled cell biological experimentation in cytoskeleton research and beyond.

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Photoswitchable epothilone-based microtubule stabilisers allow GFP imaging-compatible, optical control over the microtubule cytoskeleton

10.1101/2021.03.31.437838 ◽

2021 ◽

Author(s):

Li Gao ◽

Joyce C.M. Meiring ◽

Constanze Heise ◽

Ankit Rai ◽

Adrian Mueller-Deku ◽

...

Keyword(s):

Hydrogen Bonding ◽

Cell Division ◽

Cell Motility ◽

Ease Of Use ◽

Optical Control ◽

Optical Methods ◽

Microtubule Cytoskeleton ◽

Future Developments ◽

Microtubule Stability ◽

Cargo Transport

Optical methods to modulate microtubule stability and dynamics are promising approaches to reach the micron- and millisecond-scale resolution needed to decrypt the diverse roles of the microtubule cytoskeleton in biology. However, such optical methods have until now focussed nearly exclusively on microtubule destabilisation. Here, we introduce "STEpos" as light-responsive epothilone reagents, designed to photoswitchably bind to tubulin and stabilise lateral contacts in the microtubule lattice. Using a novel styrylthiazole photoswitch, designed to allow the hydrogen-bonding that is key to epothilone potency, we have created the first set of GFP-orthogonal photoswitchable microtubule stabilisers. The STEpos can photocontrol microtubule polymerisation, cell division, and cellular microtubule dynamics with micron- and second-scale spatiotemporal precision. STEpos offer substantial improvements of potency, solubility, and ease-of-use compared to the only previous photopharmaceuticals for microtubule stabilisation. The intriguing structure-photoswitching activity relationship insights from this work will also assist future developments of improved STEpo reagents, and we anticipate that these will contribute greatly to high-precision cytoskeleton research across the fields of biophysics, cargo transport, cell motility, cell division, development, and neuroscience.

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On-site optical control for solar mirrors

Future Energy, Environment and Materials ◽

10.2495/feem130411 ◽

2014 ◽

Author(s):

D. Fontani ◽

P. Sansoni ◽

S. Coraggia ◽

L. Mercatelli ◽

D. Jafrancesco ◽

...

Keyword(s):

Optical Control

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PHOTACs Enable Optical Control of Protein Degradation

10.26434/chemrxiv.8206688 ◽

2019 ◽

Cited By ~ 2

Author(s):

Martin Reynders ◽

Bryan Matsuura ◽

Marleen Bérouti ◽

Daniele Simoneschi ◽

Antonio Marzio ◽

...

Keyword(s):

Protein Degradation ◽

E3 Ligase ◽

Optical Control ◽

Cellular Proteins ◽

Bifunctional Molecules ◽

Protein Levels ◽

Lead Compounds ◽

Subsequent Degradation ◽

Temporal And Spatial ◽

Precision Therapeutics

PROTACs (proteolysis targeting chimeras) are bifunctional molecules that tag proteins for ubiquitylation by an E3 ligase complex and subsequent degradation by the proteasome. They have emerged as powerful tools to control the levels of specific cellular proteins and are on the verge of being clinically used. We now introduce photoswitchable PROTACs that can be activated with the temporal and spatial precision that light provides. These trifunctional molecules, which we named PHOTACs, consist of a ligand for an E3 ligase, a photoswitch, and a ligand for a protein of interest. We demonstrate this concept by using PHOTACs that target either BET family proteins (BRD2,3,4) or FKBP12. Our lead compounds display little or no activity in the dark but can be reversibly activated to varying degrees with different wavelengths of light. Our modular and generalizable approach provides a method for the optical control of protein levels with photopharmacology and could lead to new types of precision therapeutics that avoid undesired systemic toxicity.

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