Researchers at the Mechanobiology Institute (MBI) at the National University of Singapore have discovered that the inherent 'handedness' of molecular structures directs the behaviour of individual cells and confers them the ability to sense the difference between left and right. This is a significant step forward in the understanding of cellular biology. This discovery was published in Nature Cell Biology on 23 March 2015.
Cellular decision making
Our bodies are made up of hundreds of different types of cells, each of which performs a unique and highly specialized task. Traditionally, the ability of cells to specialize in a given function was attributed to its genetic code. However, it is becoming increasingly clear that cells do not simply live by a set of inherited or pre-determined instructions. Instead, 'cellular decisions' are made dynamically, much like humans make decisions based on the information provided to us by our senses.
Although cells do not have the ability to see or hear, they do possess sensory structures that allow them to detect and measure various environmental stimuli. The application of mechanical force to the cell, for example, will be felt and the cell will respond accordingly. One of the most prominent cellular responses is to change shape and this property is reflected in the varying shapes of specialised cells.
Cellular senses have been attributed to various force-sensing cellular structures such as the cytoskeleton. This structure differs significantly from its namesake, the human skeleton, by being highly dynamic and playing roles in addition to the provision of structural support. For example, this network of molecular filaments or cables also generates internal forces that drive shape changes and even motility. As the cytoskeleton develops, individual protein filaments grow and shrink. They bundle together to form thicker fibres, and they move or contract. Each of these processes is collectively known as 'cytoskeleton dynamics'.
The question that has long intrigued scientists is how cytoskeleton dynamics can direct the behaviour of different cell types. To investigate this, MBI researchers Professor Alexander Bershadsky and Dr Tee Yee Han, in collaboration with researchers from the USA and Israel, observed the cytoskeleton in cells that were confined to a small circular area, using a technique known as "micro-patterning". This prevented the cells from changing shape and thus provided the researchers an unhindered view of cytoskeleton dynamics.
A surprising find
What was detected came as a surprise to the researchers. A pronounced left-right asymmetry was observed during cytoskeletal organisation. This asymmetry, which appeared as a whirlpool, with filaments moving anticlockwise inside the cell, was found to originate from the inherent twist that is present in individual actin filaments.
This helical twist occurs naturally as individual actin proteins join together to form the long actin cables that make up overall structure. This seemingly simple property has profound consequences as it suggests that the asymmetry of a single protein is translated to the asymmetric behaviour of a whole cell. This is akin to the twist of a screw or bolt directing the function or behaviour of the machine in which it is placed.
The ability of cells to distinguish between left and right is a phenomenon that continues to fascinate scientists. It is clear from this study that the asymmetry inherent in molecular structures can define the behaviour of whole cells, and this provides new insight into the ability of cells to 'make decisions' based on the mechanical properties of its environment. However, these findings also raise fascinating questions as to whether the same phenomenon can influence the formation and function of our organs, or even affect organism behaviour.
Indeed relatively simple biological systems, such as cells grown on defined patterns, display a pronounced asymmetry in their movement. At the other extreme, brain function and human cognition is dependent on the asymmetric behaviour of nerve cells. The possibility that the inherent asymmetry of molecular structures can define cell, tissue or even organism behaviour will undoubtedly drive further studies for years to come.
Amal Naquiah | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences