Electricity is a key component of living bodies. We know that voltage differences are important in biological systems; they trigger the heartbeat and allow the neurons to communicate with each other. But for decades, it has not been possible to measure voltage differences between organelles – membrane-wrapped structures within a cell – and the rest of the cell.
The pioneering technology created by scientists from UChicaga, however, allows researchers to peek into cells to see how many different organelles use voltages to perform their functions.
“Scientists have long noticed that charged dyes used to stain cells will get stuck in mitochondria,” explained graduate student Anand Saminathan, the first author of the article, published in Nanotechnology of nature. “But little work has been done to investigate the membrane potential of other organelles in living cells.”
UChicaga’s Krishnan Laboratory specializes in building tiny sensors to travel inside cells and report on what’s happening so researchers can understand how cells work and how they break down in diseases or disorders. Earlier, they built such machines for studying neurons and lysosomes, among other things.
In this case, they decided to use a technique to investigate the electrical activities of organelles within living cells.
In the membranes of neurons, there are proteins called ion channels that act as a passage for charged ions to enter and exit the cell. These channels are necessary for neuronal communication. Previous research has shown that organelles have similar ion channels, but we were not sure what role they played.
A new research tool, called Voltair, allows for further research on this issue. It works like a voltmeter that measures the voltage difference in two different areas within a cell. Voltaire is made of DNA, which means that it can go directly into the cell and access deeper structures.
In their initial studies, the researchers looked for membrane potentials – the difference in voltage inside the organelle compared to the outside. They found evidence for such potentials in several organelles, such as trans-Golgi networks and endosome recycling, which were previously thought to have no membrane potential at all.
“So I think the membrane potential in the organelles could play a bigger role – maybe it helps the organelles to communicate,” said Prof. Yamuna Krishnan, an expert in molecular devices based on nucleic acid.
Their studies are just the beginning, the authors said; Voltair offers a way for researchers in many fields to answer questions they have never even been able to ask. It can also be used in plants.
“This new development will at least start talks, and may even inspire a new field of research,” Saminathan said.
Understanding ‘membranes’ in membrane-free organelles
Anand Saminathan et al. DNA-based voltmeter for organelles, Nanotechnology of nature (2020). DOI: 10.1038 / s41565-020-00784-1
Provided by the University of Chicago
Citation: Scientists pioneering new method of measuring electricity in cells (2020, December 24) downloaded on December 24, 2020 from https://phys.org/news/2020-12-scientists-method-electricity-cells.html
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