Cell communication is essential for the development of any organism. Scientists know that cells have the power to "talk" to one another, sending signals through their membranes in order to "discuss" what kind of cell they will ultimately become — whether a neuron or a hair, bone, or muscle. And because cells continuously multiply, it's easy to imagine a cacophony of communication.
But according to Dr. David Sprinzak, a new faculty recruit of Tel Aviv University's Department of Biochemistry and Molecular Biology at the George S. Wise Faculty of Life Sciences, cells know when to transmit signals — and they know when it's time to shut up and let other cells do the talking. In collaboration with a team of researchers at the California Institute of Technology, Dr. Sprinzak has discovered the mechanism that allows cells to switch from sender to receiver mode or vice versa, inhibiting their own signals while allowing them to receive information from other cells — controlling their development like a well-run business meeting.
Dr. Sprinzak's breakthrough can lead to the development of cancer drugs that specifically target these transactions as needed, further inhibiting or encouraging the flow of information between cells and potentially stopping the uncontrollable proliferation of cancer cells. Dr. Sprinzak's research appeared in the journal PLoS Computational Biology.
Over and out
A cell's communications behavior is mediated by the "Notch signalling pathway," one of the major communication channels between neighboring cells. Information is transferred between cells when Notch receptors from one cell come into contact with Delta molecules, or signals, from another cell. But when the same Delta molecules interact with Notch receptors in the same cell, Dr. Sprinzak found, they shut down their activity and prevent reception of signals from the outside world.
The researchers set out to learn how. In the lab, Dr. Sprinzak and his team attached fluorescent proteins to both Notches and Deltas to track the flow of information. What they found was that the Notch receptors and the Delta signals are actually capable of binding to each other, effectively shutting down each other's activity and forcing the cells into either sender or receiver modes.
"In one state, a cell can send a message and not receive, and in the other it receives and cannot send. They can talk or listen, but they cannot do both at the same time," says Dr. Sprinzak. He compares this communications system to a walkie talkie, in which only one user may be "on the air" at a time.
This switch is crucial to helping the cells make yes-and-no decisions in which neighboring cells adopt distinct fates. Such "cell fate" decisions are responsible for formation of boundaries between developmental tissues, such as those between the vertebrae protecting our spine. They can also account for many patterns of differentiation in the body, such as the pattern of neurons in our brain, or sensory hairs in the inner ear.
Far from enigmatic, this process can actually be seen in the lab. By measuring the fluorescence in real time, it is possible to watch how the levels of a cell's own Delta activity affect the ability of a cell to transfer messages to its neighbors.
Understanding biology through mathematical models
Sender and receiver behavior, says Dr. Sprinzak, not only determines how cells differentiate normally, but also how they differentiate in abnormal situations, such as when cancer cells are growing.
A physicist-turned-biologist, Dr. Sprinzak will next apply mathematical models to analyze the dynamics between the cells and quantify the switch between sender and receiver. Part of an emerging field called Systems Biology, Dr. Sprinzak's work uses tools from mathematics and physics to understand biology on a systematic level. Mathematical equations can help us to better understand the interactions between the genes and proteins in our body which determine cellular behavior and differentiation, he says.
American Friends of Tel Aviv University (www.aftau.org) supports Israel's leading, most comprehensive and most sought-after center of higher learning. Independently ranked 94th among the world's top universities for the impact of its research, TAU's innovations and discoveries are cited more often by the global scientific community than all but 10 other universities.
Internationally recognized for the scope and groundbreaking nature of its research and scholarship, Tel Aviv University consistently produces work with profound implications for the future.
George Hunka | EurekAlert!
Cnidarians remotely control bacteria
21.09.2017 | Christian-Albrechts-Universität zu Kiel
Immune cells may heal bleeding brain after strokes
21.09.2017 | NIH/National Institute of Neurological Disorders and Stroke
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
21.09.2017 | Physics and Astronomy
21.09.2017 | Life Sciences
21.09.2017 | Health and Medicine