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

August 3, 2012

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 , is involved in a variety of crucial tasks. It is used by 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.

This video is not supported by your browser at this time.
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 is the first to follow changes in the shape of the cell’s membrane and track proteins thought to influence those changes. Credit: EMBL/W.Kukulski

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 first under a and then with the higher resolution of an . 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 , 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.

Explore further: Cells use import machinery to export their goods as well

More information: Kukulski, W., Schorb, M., Kaksonen, M. & Briggs, J.A.B. Time-resolved electron tomography reveals how the plasma membrane is reshaped during endocytosis. Cell, 3 August 2012.

Related Stories

Cells use import machinery to export their goods as well

July 3, 2009

(PhysOrg.com) -- In the bustling economy of the cell, little bubbles called vesicles serve as container ships, ferrying cargo to and from the port — the cell membrane. Some of these vesicles, called post-Golgi vesicles, ...

Nanotubes: Cellular membranes on supply

March 11, 2011

(PhysOrg.com) -- When unfolding a tent for the first time, you may wonder how the huge tarpaulin fits into a bag the size of a football. Biologists wonder about something similar: when a cell divides, the surface area of ...

New method for imaging molecules inside cells

June 28, 2011

Using a new sample holder, researchers at the University of Gothenburg, Sweden, have further developed a new method for imaging individual cells. This makes it possible to produce snapshots that not only show the outline ...

'Transformer' protein makes different sized transport pods

May 25, 2012

These spheres may look almost identical, but subtle differences between them revealed a molecular version of the robots from Transformers. Each sphere is a vesicle, a pod that cells use to transport materials between different ...

Recommended for you

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.