Researchers at the University of Illinois at Chicago have found that intra-cellular trafficking is tightly coordinated for maximum flow through cellular compartments -- much as vehicles on a crowded road are allowed to pass quickly through a succession of green traffic lights.
The molecular mechanism that underlies this coordination is reported by lead researcher Nava Segev, UIC professor of biological sciences, in the November issue of Nature Cell Biology.
While the finding was made using yeast cells, intra-cellular mechanisms discovered in yeast almost invariably correspond to processes in mammalian cells, including humans, and the mechanism Segev described may find applicability in the biomedical field.
"Every system in our body depends on intra-cellular trafficking, because anything that goes from the inside of a cell to the outside, or from outside to inside, uses this process," Segev said. "Malfunctioning of this pathway can cause a variety of human diseases. For example, problems in insulin secretion or presentation of insulin-receptors on the cell membrane result in diabetes. Defects in growth factor secretion and presentation of their receptors on cells result in cancer. Defects in neurotransmitter release or internalization result in brain disorders."
A special set of proteins is responsible for the coordination. Molecular switches that go by the letters Ypt allow membrane-enclosed vesicles to pass in and out of cellular compartments. Activator proteins flip the switches on. One activator protein, called TRAPP, coordinates two Ypt switches for quick entrance and subsequent exit from a central cellular compartment known as the Golgi apparatus.
"The Golgi is a central station in all cells, through which all intra-cellular traffic passes," Segev explained.
Specific subunits of TRAPP previously identified by the UIC researchers were found to be the key to coordinated switching and traffic flow through the Golgi. They have now shown that components of TRAPP act in sequence to direct the flow. One form of TRAPP turns on the first Ypt for entry into the Golgi, while at the other end of the Golgi, two subunits join TRAPP to activate the Ypt required for exit from the Golgi, Segev said.
Segev said the mechanism that her lab identified must now be shown to exist in mammalian cells. Her earlier discovery of the Ypt molecular switches in yeast and the subsequent finding of their homologues in mammalian cells, together with the fact that TRAPP is conserved in evolution from yeast to man, lead her to believe the entire coordinated switching mechanism is universal.
Paul Francuch | EurekAlert!
Atomic-level motion may drive bacteria's ability to evade immune system defenses
24.04.2017 | Indiana University
Two-dimensional melting of hard spheres experimentally unravelled after 60 years
24.04.2017 | University of Oxford
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
24.04.2017 | Physics and Astronomy
24.04.2017 | Materials Sciences
24.04.2017 | Life Sciences