How cells keep in shape

Dec 02, 2007
How cells keep in shape
The fluorescence microscope image shows microtubules in red and plus-end tracking proteins that label growing microtubule ends in green. Credit: Peter Bieling, EMBL

Cells in our body come in various shapes and sizes. Each cell is shaped in such a way as to optimise it for a specific function. When things go wrong and a cell does not adopt its dedicated shape, its function can be impaired and the cell can cause problems in the body.

Researchers at the European Molecular Biology Laboratory (EMBL) and the Institute for Atomic and Molecular Physics (AMOLF), The Netherlands, have now decoded a molecular mechanism that plays an important role in the development of a cell’s shape. In this week’s issue of Nature they report a new experimental approach that sheds light on the interaction between proteins and the cell’s skeleton.

That each cell type has its unique shape is due to its cytoskeleton, an internal scaffold built of protein filaments. Especially important are microtubules, dynamic filaments that constantly grow and shrink. Their spatial organisation inside cells depends on a variety of regulator proteins, some of which only interact with the growing ends of these filament.

How these so called plus-end tracking proteins recognise the dynamic structure of a growing microtubule end is a long-standing puzzle. Researchers in the groups of Thomas Surrey and Damian Brunner at EMBL and of Marileen Dogetrom at AMOLF have now developed the first method that allows to simultaneously study multiple plus-end tracking molecules, so called +TIPs, in the test tube.

“+TIPs specifically bind to the fast-growing plus end of a microtubule and follow it as it grows. They act as a plus-end label so that other proteins know where to bind to regulate the filament’s stability,” says Surrey. “For years it has been impossible to reconstitute this behaviour in a test tube. Our new system now revealed which proteins need to be present for plus-end tracking and what the underlying mechanisms are.”

Applying the new method they succeeded in dissecting a minimal molecular system consisting of three end tracking proteins from yeast cells. The proteins were labelled with fluorescence to monitor their behaviour with a microscope. This procedure revealed that one of the proteins has the ability to recognise the specific structure of the growing microtubule tip, binds to it and acts as a loading platform for the other two proteins. The inherent motor activity of one of the other two proteins, which allows it to walk along microtubules, contributes to the ability of the molecular system to follow growing microtubule ends selectively.

“The great advantage of our new assay is that it can be applied to all kinds of other proteins that interact with microtubules,” says Peter Bieling, who carried out the research in Surrey’s lab. “It is a powerful approach that will advance our understanding of the large variety of different microtubule end tracking proteins and can shed light on their mechanics and functions.”

Source: European Molecular Biology Laboratory

Explore further: East African honeybees are safe from invasive pests... for now

add to favorites email to friend print save as pdf

Related Stories

Researchers show fruit flies have latent bioluminescence

Apr 10, 2014

New research from Stephen C. Miller, PhD, associate professor of biochemistry and molecular pharmacology, shows that fruit flies are secretly harboring the biochemistry needed to glow in the dark—otherwise ...

JILA's short, flexible, reusable AFM probe

Apr 09, 2014

(Phys.org) —JILA researchers have engineered a short, flexible, reusable probe for the atomic force microscope (AFM) that enables state-of-the-art precision and stability in picoscale force measurements. ...

Recommended for you

Scientists tether lionfish to Cayman reefs

1 hour ago

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

Deadly human pathogen Cryptococcus fully sequenced

12 hours ago

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

HenisDov
not rated yet Dec 03, 2007

How Cells Keep In Shape? No,
What Genomes Do With Building Materials!

(1)
http://www.physor...383.html

- "Each cell is shaped in such a way as to optimise it for a specific function".

- "...will advance our understanding of the large variety of different microtubule end tracking proteins and can shed light on their mechanics and functions.%u201D


(2)
http://blog.360.y...Q--?cq=1&p=372

Chapter I.D., "Cells Are Not Organisms"

- Scientifically, cells are NOT organisms. The outer cell membrane is an Organ. Plain and simple...it is a multifunctional organ of the genome...cellular membranes and cells' contents are evolution products of the in-cell organisms, the genomes. Continued reference to cells as organisms is a gross anachronism that brakes/slows developement of life sciences.

(3)
A Cell, in and out, is not only "specific application shaped" but also "specific application equipped", and the questions are:

- WHEN does it thus become "dedicated" by its genome, and

- How does it thus become "dedicated" by its genome, and

- Can/Does the genome ever "undedicate a location-specific-application-dedicated cell".

Dov Henis

More news stories

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Leeches help save woman's ear after pit bull mauling

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

Venture investments jump to $9.5B in 1Q

Funding for U.S. startup companies soared 57 percent in the first quarter to a level not seen since 2001, as venture capitalists piled more money into an increasing number of deals, according to a report due out Friday.