In order for cells to function properly, cargo needs to be constantly transported from one point to another within the cell, like on a goods station.
This cargo is located in or on intracellular membranes, called vesicles. These membranes have a signature, and only those with the correct signature may fuse with the membrane of another organelle into one compartment.
Capture of a vesicle by an endosome by the tethering factor EEA1 binding Rab5. Active Rab5 (shiny blue particles) induces a change in flexibility of EEA1 (green filaments) generating an entropic collapse force that pulls the vesicle toward the target membrane to dock and fuse.
Credit: Mario Avellaned
The membrane itself must be recognized by a target membrane, which employs long tethering proteins to find its match.
David Murray and Marcus Jahnel from the labs of Marino Zerial at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) and Stephan Grill at the Biotechnology Center of the TU Dresden were curious to find out how these large tether proteins are able to recognize the signature of a membrane compartment and pull it in in order for the small fusion proteins to engage.
They and their colleagues discovered that when the vesicle docks by an active protein called Rab5, GTPase, this protein is sending a message along the rigid tether protein to become flexible.
This change in flexibility results in a force that starts the vesicle's trip towards the target membrane to initiate docking and fusion.
This newly found mechanism is published in the journal Nature and intuitively explains how traffic within the cell can be efficient and selective, and resolves a paradox of sizes.
Prof. Dr. Stephan Grill | EurekAlert!
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences