'Molecular activity painting' to control and monitor switch-like, light-controlled perturbations inside cells

March 30, 2017, Wiley
Credit: Wiley

The plasma membrane serves as a major hub for signal cascades to control crucial cellular processes. But it is a fluid medium, which makes the signaling processes difficult to monitor. Now, German scientists have designed a molecular "paintbrush" technique to trigger, control, and also monitor signaling processes. As they write in the journal Angewandte Chemie, their modular system made of light-activatable molecular building blocks can, for example, induce patterned contraction inside living cells.

The is a tight lipid barrier surrounding the cell. Membrane proteins control the influx and efflux of water, ions, proteins, and other compounds. Extracellular signals are transduced by receptors through the to trigger intracellular processes like cell movement or differentiation. The visualization of such events at a molecular level is still a major challenge, mainly because of the fast diffusion of the protein receptors in the plasma membrane. Therefore, the groups of Leif Dehmelt at the Max Planck Institute of Molecular Physiology and Yaowen Wu at the Chemicals Genomics Centre of the Max Planck Society, Germany, have developed a new technology termed "Molecular Activity Painting" (MAP), which combines immobilization and light-controlled activation: Artificial receptors tightly anchored on the cell substrate are furnished with a designed modular molecular system. One light pulse activates the modular , which can trigger localized signal cascades eventually leading to movements of the cytoskeleton. This technology makes the cellular response visible like a stroke of a brush on the membrane.

The core of the MAP technology is a soluble multicomponent molecule assembled from four functional parts: a chloroalkyl moiety, a polymeric (PEG) linker, a molecular group called trimethroprim or TMP, and a light-sensitive group called Nvoc. This "caged chemical dimerizer", as it is called, can fulfill several tasks: Through its chloroalkyl moiety, it binds to an artificial receptor, which is tightly anchored and immobilized on the cell substrate. The Nvoc group can be removed ("uncaged") by a single light pulse. The uncaged TMP moiety is then targeted by a designed factor to induce a signal cascade in the cell. The whole system is aimed at one purpose: control and visualization of molecular function in living .

Using this technology, the scientists induced a patterned actomyosin contraction inside a living mammalian cell. Or, more exactly, they "painted" the letter "N" on the plasma membrane of a live cell. "'Molecular Activity Painting' [...] enables switch-like, patterned perturbations of regulatory networks with micrometer precision," the scientists propose.

Explore further: Researchers discover new molecular details about protein sorting in the cell

More information: Xi Chen et al. "Molecular-Activity Painting": Switch-like, Light-Controlled Perturbations inside Living Cells, Angewandte Chemie International Edition (2017). DOI: 10.1002/anie.201611432

Related Stories

Shape-shifting molecular robots respond to DNA signals

March 2, 2017

A research group at Tohoku University and Japan Advanced Institute of Science and Technology has developed a molecular robot consisting of biomolecules, such as DNA and protein. The molecular robot was developed by integrating ...

Researchers zero-in on cholesterol's role in cells

January 17, 2017

Scientists have long puzzled over cholesterol. It's biologically necessary; it's observably harmful - and nobody knows what it's doing where it's most abundant in cells: in the cell membrane.

Recommended for you

Research gives new ray of hope for solar fuel

April 24, 2018

A team of Renewable Energy experts from the University of Exeter has pioneered a new technique to produce hydrogen from sunlight to create a clean, cheap and widely-available fuel.

Scientists have tracked down an elusive 'tangled knot' of DNA

April 23, 2018

It's DNA, but not as we know it. In a world first, Australian researchers have identified a new DNA structure—called the i-motif—inside cells. A twisted 'knot' of DNA, the i-motif has never before been directly seen inside ...

New theory shows how strain makes for better catalysts

April 20, 2018

Brown University researchers have developed a new theory to explain why stretching or compressing metal catalysts can make them perform better. The theory, described in the journal Nature Catalysis, could open new design ...

Machine-learning software predicts behavior of bacteria

April 19, 2018

In a first for machine-learning algorithms, a new piece of software developed at Caltech can predict behavior of bacteria by reading the content of a gene. The breakthrough could have significant implications for our understanding ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.