Molecular “motors” are at the root of most biological movement. They propel cell components, whole cells, and even our muscles on command. Barbara Imperiali and a team from the Massachusetts Institute of Technology (Cambridge, USA), the University of Virginia (Charlottesville, USA), and the National Institutes of Health (USA) have now provided the motor protein myosin with an “on switch” that is activated by light. As the scientists report in the journal Angewandte Chemie, this should make it possible to follow cellular processes that involve myosin in real time.
In order for our muscles to contract, two types of fibrous proteins, myosin and actin, must interact. Driven by splitting of the cellular fuel adenosine triphosphate (ATP), “buttons” on the myosin molecules attach, allowing the myosin to dangle off of the actin filaments. In non-muscular cells, myosin ensures that the cell constricts itself in the division process. Myosin consists of several different protein chains. The activity of non-muscular myosin is regulated through its regulatory light chain. As soon as a phosphate group binds to a specific site (Ser19) of the light chain (phosphorylation), myosin become active. The activity can be amplified through binding of a second phosphate group at a neighboring site (Thr18).
Myosin has been intensively studied. However, it has not been possible to examine precisely what happens after activation of the molecule in living cells both spatially and over time. This research team has now found a trick that makes real-time observations possible: A myosin molecule that can be switched on by light. To achieve this, the researchers used protein synthesis to produce a synthetic regulatory chain that already contains one or two phosphate groups. The trick is that one of the phosphate groups is covered by a cage. In this form, the chain is inactive. Irradiation with light makes the cage split off, switching on the regulatory chain and activating the myosin.
The researchers replaced the natural light chain in myosin molecules with their synthetic one and introduced this light-activated myosin into cells.
Irradiation activates it at a defined time in a defined place. In this way, the researchers hope to observe what happens after the activation of myosin in a cell in real time.Author: Barbara Imperiali, Massachusetts Institute of Technology, Cambridge (USA), http://web.mit.edu/imperiali
Show me your leaves - Health check for urban trees
12.12.2017 | Gesellschaft für Ökologie e.V.
Liver Cancer: Lipid Synthesis Promotes Tumor Formation
12.12.2017 | Universität Basel
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
12.12.2017 | Physics and Astronomy
12.12.2017 | Earth Sciences
12.12.2017 | Power and Electrical Engineering