In a new paper published in The Journal of Physiology, Murata and Okamura, from the Okazaki Institute for Integrative Bioscience, examine a voltage-sensitive phosphatase that converts an electrical to a chemical signal; they directly demonstrate that the enzyme activity of Ci-VSP changes in a voltage-dependent manner through the operation of the voltage sensor.
Prior to this work, it was unclear which phosphoinositides were the major substrates of the phosphatase activity, and whether depolarisation or hyperpolarisation induced the phosphatase activity. By expressing phosphoinositide-specific sensors in Xenopus oocytes and applying both electrophysiology and imaging of phosphoinositides, it was shown that enzyme activity is activated upon depolarisation (not upon hyperpolarisation), and that levels of both PtdIns(4,5)P2 and PtsIns(3,4,5)P3 are regulated by the operation of voltage sensor.
“Our findings identify common principles of the voltage sensor shared between voltage-gated ion channels and the voltage-sensing phosphatase," comment the authors. "There is no question that the VSP is a much simpler model than ion channels for understanding the mechanisms of voltage sensing, and understanding the VSP will provide insights into the function of ion channels as well.
Such knowledge is critical for understanding general mechanisms of voltage sensing and many disorders coupled with altered membrane excitabilities. The VSP’s ability to tune phosphoinositide phosphatase activity by voltage will also serve as an important molecular tool to understand mechanisms of tumor suppressor phosphatase, PTEN, and other phosphatases that underlie carcinogenesis and metabolic disorders."
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
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