How the cell swallows

3D movie at 'ultraresolution' shows how cell's machinery bends membrane inwards

2012-08-03

(Press-News.org) VIDEO: Scientists at EMBL have combined the power of two kinds of microscope to produce a three-dimensional movie of how cells ‘swallow’ nutrients and other molecules by engulfing them. The study...
Click here for more information.

Scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have combined the power of two kinds of microscope to produce a 3-dimensional movie of how cells 'swallow' nutrients and other molecules by engulfing them. The study, published today in Cell, is the first to follow changes in the shape of the cell's membrane and track proteins thought to influence those changes. It also provides ample data to investigate this essential process further. This 'swallowing', called endocytosis, is involved in a variety of crucial tasks. It is used by brain cells relaying information to each other, for instance, and is also hijacked by many viruses, which use it to invade their host's cells. When a cell is about to swallow some molecules, a dent appears in the cell's membrane, and gradually expands inwards, pinching off to form a little pouch, or vesicle, that transports molecules into the cell. To investigate how the cell's machinery pulls in the membrane and forms the vesicle, researchers led by Marko Kaksonen and John Briggs employed a method they developed two years ago to faithfully follow the exact same molecules first under a light microscope and then with the higher resolution of an electron microscope. This enabled them to combine two sets of data that so far could only be obtained in isolation: the timing and sequence with which different components of the cell's machinery arrive at the vesicle-to-be, and the 3D changes to membrane shape that ultimately form that vesicle. They discovered, for instance, that the first proteins to arrive on the inside of the cell's membrane are not able to start bending it inwards until a network of the cell's scaffolding protein, actin, forms and starts pulling on the membrane. The data used to make the video is freely available to the scientific community and will, Kaksonen and Briggs believe, provide valuable information to others trying to develop physical models of how this process works. The EMBL scientists themselves are probing the roles of individual proteins in this process, by perturbing them, and would like to extend the current work in yeast to human cells.

### The video accompanying this release is also available on the EMBL YouTube Channel: http://youtu.be/50eIv8FN-lk.

ELSE PRESS RELEASES FROM THIS DATE:

Bacterial community inside the plant root

2012-08-03

This press release is available in German.Soil is the most species-rich microbial ecosystem in the world. From this incredible diversity, plants specifically choose certain species, give them access to the root and so host a unique, carefully selected bacterial community from which they then benefit in a variety of ways. To achieve this, the plant's immune system must be able to tell which of these bacteria are friends and which foes. Researchers from the Max Planck Institute for Plant Breeding Research in Cologne and the Max Planck Institute for Marine Microbiology in ...

Ethylene of no effect -- why peppers do not mature after picking

2012-08-03

This press release is available in German.Tomato breeders scored a coup several years ago when they identified tomatoes with a genetic defect that made the fruits mature very slowly, even under the influence of the phytohormone ethylene. Traders and growers were delighted as it gave them more time to transport the crop, initially still green, from where it was harvested to where it would be sold. At the stores, the tomatoes could then be treated with ethylene to bring them to maturity. Other fruits, like peppers, grapes and strawberries, generally do not mature after picking; ...

Mystery of elephant infrasounds revealed

2012-08-03

Elephants can communicate using very low frequency sounds, with pitches below the range of human hearing. These low-frequency sounds, termed "infrasounds", can travel several kilometers, and provide elephants with a "private" communication channel that plays an important role in elephants' complex social life. Their frequencies are as low as the lowest notes of a pipe organ. Although the sounds themselves have been studied for many years, it has remained unclear exactly how elephant infrasounds are made. One possibility, favored by some scientists, is that the elephants ...

MAK value lowered for chlorinated biphenyls

2012-08-03

This press release is available in German.Chlorinated biphenyls (PCBs) are a group of substances for which the 2012 List of MAK and BAT Values submitted by the Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) specifies new, and in this case, significantly lower values than previously recommended. The current list, which was presented to the German Federal Minister of Labour and Social Affairs as in every year, and which is the basis for legislation on ...

NUS researchers identify a novel double-stranded DNA structure

2012-08-03

Contact: Tsueyling Yong sciytl@nus.edu.sg 65-651-67874 Carolyn Fong Carolyn@nus.edu.sg 65-6516-5399 National University of Singapore NUS researchers identify a novel double-stranded DNA structure Researchers' findings address a scientific debate that had lasted for 16 years over the existence of a double-stranded DNA structure Double-stranded DNA has often been described as a right-handed helical structure, known as B-DNA. To perform its multiple functions, double-stranded DNA has multiple structures depending on conditions. For example, the melted DNA ...

People with allergies may have lower risk of brain tumors

2012-08-03

COLUMBUS, Ohio - New research adds to the growing body of evidence suggesting that there's a link between allergies and reduced risk of a serious type of cancer that starts in the brain. This study suggests the reduced risk is stronger among women than men, although men with certain allergy profiles also have a lower tumor risk. The study also strengthens scientists' belief that something about having allergies or a related factor lowers the risk for this cancer. Because these tumors, called glioma, have the potential to suppress the immune system to allow them to grow, ...

MDC researchers develop new approach to treat acute liver failure

2012-08-03

Acute liver failure is a life-threatening disease, characterized by a sudden, massive death of liver cells. Unfortunately, few treatment options exist, especially for advanced-stage liver failure. As a last resort a liver transplant may be the only remaining option. Now the physician Dr. Junfeng An of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch and Dr. Stefan Donath, a specialist in internal medicine and cardiology, also of the MDC and Helios Klinikum Berlin-Buch, have developed a new treatment approach based on a mouse model. In their current study ...

Major step taken towards 'unbreakable' message exchange

2012-08-03

Single particles of light, also known as photons, have been produced and implemented into a quantum key distribution (QKD) link, paving the way for unbreakable communication networks. The results of the experiment, undertaken by a close collaboration of researchers based in Wuerzburg, Munich and Stuttgart, have been published today, Thursday 2 August, in the Institute of Physics and German Physical Society's New Journal of Physics. The single photons were produced using two devices made of semiconductor nanostructures that emitted a photon each time they were excited ...

Students with strong hearts and lungs may make better grades, study finds

2012-08-03

ORLANDO, Fla. -- Having a healthy heart and lungs may be one of the most important factors for middle school students to make good grades in math and reading, according to findings presented at the American Psychological Association's 120th Annual Convention. "Cardiorespiratory fitness was the only factor that we consistently found to have an impact on both boys' and girls' grades on reading and math tests," said study co-author Trent A. Petrie, PhD, professor of psychology and director of the Center for Sport Psychology at the University of North Texas. "This provides ...

Parents get physical with unruly kids, study finds

2012-08-03

EAST LANSING, Mich. — Parents get physical with their misbehaving children in public much more than they show in laboratory experiments and acknowledge in surveys, according to one of the first real-world studies of caregiver discipline. The study, led by Michigan State University's Kathy Stansbury, found that 23 percent of youngsters received some type of "negative touch" when they failed to comply with a parental request in public places such as restaurants and parks. Negative touch included arm pulling, pinching, slapping and spanking. "I was very surprised to see ...

LAST 30 PRESS RELEASES:

Personal info and privacy control may be key to better visits with AI doctors

NIH study demonstrates long-term benefits of weight-loss surgery in young people

Sustained remission of diabetes and other obesity-related conditions found a decade after weight loss surgery in adolescence

Antarctic penguin colonies can be identified and tracked from tourists' photos, using a computer model to reconstruct the 3D scene

For patients with alcohol use disorder, exercise not only reduces alcohol dependence, but also improves mental and physical health, per systematic review