The study was published in the July 31 issue of the Journal of Cell Biology.
The sense of top and bottom is often lost in cells that become cancerous and may be an important factor in metastasis.
Cells depend on the location of a number of proteins and lipids to recognize and maintain their polarity. Moving these lipids and proteins from where they are produced to where they are needed is a dynamic process.
Dr. Athar Chishti, professor of pharmacology at the UIC College of Medicine and principal investigator of the study, said researchers knew that a lipid called PIP3 is very important in signalling polarity. But the process everyone wanted to understand, he said, "was the trafficking and disposition of this lipid to where it was needed at the growing tips of the cells."
Chishti's research team, including Kaori Horiguchi and Dr. Toshihiko Hanada, determined that one domain of a molecular motor protein called a kinesin that they had discovered interacted with PIP3 binding protein. They showed that the kinesin and this binding protein motored the PIP3 along microtubules -- the tracks upon which the kinesins move their cargoes.
They also showed that the kinesin-binding adaptor and PIP3 were found together at the tips of the nerve cells and that in one of these cell types these molecules were most abundant in the longest extension, called the axon.
"We found the motor, the binding domains and an adaptor," said Chishti. "When the adaptor binds PIP3, it is delivered to the membrane where it is needed, and if you block this process, polarity is lost."
In some cells, like neurons, there are dramatic differences in the structure and function of the different ends of a cell. But even in cells where the difference between the ends is not as obvious, the delivery process is essential. Loss of cell polarity is often the first step in converting a normal cell to a cancer cell, Chishti said.
The discovery illuminates a key step in the trafficking and disposition of polarity determinants. Science magazine highlighted the Chishti paper as an Editor's Choice in the August 18th issue and in this week's Signal Transduction Segment online at http://stke.sciencemag.org/.
"Now we know the cargo, and we know the motor," said Chishti. "The next step will be to find out what turns the motor on and tells it to start down the track to deliver the cargo.
"In the kinesin field, there are two fundamental questions: what are the cargoes, and what turns the motors on and off that carry them."
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...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy