Proteins found to spontaneously form whorls and lattices

March 28, 2012 by Bob Yirka report
Emergence of vortices of microtubules. Image (c) Nature 483, 448-452

( -- Building on the work of a previous team that found filaments made from actin, when combined with so called motor proteins, moved themselves into distinct patterns, a new team in Japan has found that combining different proteins results in the formation of far more elaborate patterns such as individual whorls and over time whole lattices. The team made up of a diverse group of researchers from across Japan, have published their findings in Nature.

This new work is part of a larger effort in the physics community involved in studying the means by which groups of organisms spontaneously move collectively, such as birds in a flock or fish in a school; all appearing to move as if of one mind. But because of the complexity of such large groups, scientists have turned to organisms with the same types of abilities but are much less complex. To that end, some have begun looking at proteins which are able to move and coalesce into patterns on a glass slide which can be watched using a simple microscope.

Recently, one group found that when combining filaments made from , with , the would order themselves into waves or even spirals. This new research shows that such ordering can be far more profound if the right combinations of ingredients are used.

The Japanese team started with a called a microtubule, then added a motor protein called dynein. When paired the two join, as if adding a motor to a boat. When the motor protein starts running, fed by , the microtubules are propelled around in a liquid material, like boats on water.

The researchers found that when they created enough of these little protein motor boats in the same pool on a glass slide, they at first seemed to putter aimlessly about, but after time, they soon began arranging themselves into individual whorls. And then, over a longer period of time the whorls began to form lattices. And that wasn’t all; they found by looking closer that individual were able to move around not just within the individual whorls, but between them, without disturbing either.

The research team readily admit they have no idea how or why the patterns emerge but do believe finding answers to such questions will likely lead to explaining how larger organisms are able to move collectively as well.

Explore further: Roadworks on the motorways of the cell

More information: Large-scale vortex lattice emerging from collectively moving microtubules, Nature 483, 448–452 (22 March 2012) doi:10.1038/nature10874

Spontaneous collective motion, as in some flocks of bird and schools of fish, is an example of an emergent phenomenon. Such phenomena are at present of great interest and physicists have put forward a number of theoretical results that so far lack experimental verification. In animal behaviour studies, large-scale data collection is now technologically possible, but data are still scarce and arise from observations rather than controlled experiments. Multicellular biological systems, such as bacterial colonies or tissues, allow more control, but may have many hidden variables and interactions, hindering proper tests of theoretical ideas. However, in systems on the subcellular scale such tests may be possible, particularly in in vitro experiments with only few purified components. Motility assays, in which protein filaments are driven by molecular motors grafted to a substrate in the presence of ATP, can show collective motion for high densities of motors and attached filaments. This was demonstrated recently for the actomyosin system, but a complete understanding of the mechanisms at work is still lacking. Here we report experiments in which microtubules are propelled by surface-bound dyneins. In this system it is possible to study the local interaction: we find that colliding microtubules align with each other with high probability. At high densities, this alignment results in self-organization of the microtubules, which are on average 15 µm long, into vortices with diameters of around 400 µm. Inside the vortices, the microtubules circulate both clockwise and anticlockwise. On longer timescales, the vortices form a lattice structure. The emergence of these structures, as verified by a mathematical model, is the result of the smooth, reptation-like motion of single microtubules in combination with local interactions (the nematic alignment due to collisions)—there is no need for long-range interactions. Apart from its potential relevance to cortical arrays in plant cells and other biological situations, our study provides evidence for the existence of previously unsuspected universality classes of collective motion phenomena.

Related Stories

Roadworks on the motorways of the cell

December 28, 2006

A cell is a busy place. In a permanent rush hour, molecules are transported along a dynamic motorway system made up of filaments called microtubules. Microtubules constantly grow and shrink and are rapidly assembled wherever ...

A model system for group behavior of nanomachines

September 1, 2010

For the casual observer it is fascinating to watch the orderly and seemingly choreographed motion of hundreds or even thousands of fish, birds or insects. However, the formation and the manifold motion patterns of such flocks ...

One-dimensional Diffusion Accelerates Molecular Motors

May 12, 2006

Max Planck scientists have identified a new strategy which motor proteins use to move. The research was carried out by Prof. Jonathon Howard and Stefan Diez at the Max Planck Institute of Molecular Cell Biology and Genetics ...

Atomic model of tropomyosin bound to actin

February 15, 2011

New research sheds light on the interaction between the semi-flexible protein tropomyosin and actin thin filaments. The study, published by Cell Press on February 15th in the Biophysical Journal, provides the first detailed ...

How a molecular traffic jam impacts cell division

November 7, 2011

Interdisciplinary research between biology and physics aims to understand the cell and how it organizes internally. The mechanisms inside the cell are very complicated. LMU biophysicist Professor Erwin Frey, who is also a ...

Recommended for you

How the Earth stops high-energy neutrinos in their tracks

November 22, 2017

Neutrinos are abundant subatomic particles that are famous for passing through anything and everything, only very rarely interacting with matter. About 100 trillion neutrinos pass through your body every second. Now, scientists ...

Quantum internet goes hybrid

November 22, 2017

In a recent study published in Nature, ICFO researchers led by ICREA Prof. Hugues de Riedmatten report an elementary "hybrid" quantum network link and demonstrate photonic quantum communication between two distinct quantum ...

Lightning, with a chance of antimatter

November 22, 2017

A storm system approaches: the sky darkens, and the low rumble of thunder echoes from the horizon. Then without warning... Flash! Crash!—lightning has struck.

Enhancing the quantum sensing capabilities of diamond

November 22, 2017

Researchers have discovered that dense ensembles of quantum spins can be created in diamond with high resolution using an electron microscopes, paving the way for enhanced sensors and resources for quantum technologies.

Study shows how to get sprayed metal coatings to stick

November 21, 2017

When bonding two pieces of metal, either the metals must melt a bit where they meet or some molten metal must be introduced between the pieces. A solid bond then forms when the metal solidifies again. But researchers at MIT ...


Adjust slider to filter visible comments by rank

Display comments: newest first

Mar 28, 2012
This comment has been removed by a moderator.
1 / 5 (5) Mar 28, 2012
See Gerald Pollack's Cells, Gels and the Engines of Life. Proteins appear to structure the water around them. In fact, this was the theoretical basis for the creation of the MRI technology. The results of this current paper are incredibly important, for it is a vital clue in the search for the origin of life. The patch-clamp technique has demonstrated that inert polymers can replicate many of the features of living cells. There is much promise in this avenue of investigation, if it will be funded.

See paper titled, "Hypothesis: the origin of life in a hydrogel environment" by Trevors and Pollack.
1 / 5 (4) Apr 07, 2012
Order from disorder
Collective motion emerges spontaneously in wiggling protein strands.

EarthLife Genesis From Aromaticity/H-Bonding

Natural selection is E (energy) temporarily constrained in an m (mass) format.
Natural selection is a universal ubiquitous trait of ALL mass spin formats, inanimate and animate.

Dov Henis
(comments from 22nd century)

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.