Proteomics reveals the E-cadherin interaction network
Researchers at the Mechanobiology Institute at the National University of Singapore have comprehensively described the network of proteins involved in cell-cell adhesions, or the cadherin interactome. This work was published in Science Signaling (Guo et al. E-cadherin interactome complexity and robustness resolved by quantitative proteomics, Science Signaling, 02 Dec 2014, Vol 7, Issue 354).
Unlocking the complexity of cell adhesion
Many biological processes depend on the ability of cells to stick to one another. The formation of multicellular organisms and precise embryonic development rely on this property, as does the maintenance of healthy tissue. Defects in the ability of cells to adhere to one another have been found in many diseases, such as cancer, Alzheimer’s disease and cardiovascular disease. In the case of cancer, ineffective cell adhesion allows tumour cells to detach and invade other tissues, thereby spreading cancer throughout the body.
Cell-cell adhesion is made possible through various cellular structures that are collectively known as cell-cell adhesion complexes. The most prominent cell-cell adhesion complex is the Adherens Junction. Central to adherens junctions is a protein known as E-cadherin, or epithelial cadherin. E-cadherin spans the cell membrane, providing a link between the interior, and exterior of the cell.
Outside the cell, E-cadherin binds to other E-cadherins from neighbouring cells in a mechanism that can be described as a ‘cellular handshake’. On the inside of the cell, E-cadherin binds to linker proteins known as catenins, which attach to a structural scaffold that lies adjacent to the adhesion site, the actin cytoskeleton. This physical link between the cytoskeletons of neighboring cells allows for the generation and transduction of mechanical signals.
Despite their importance in cell-cell adhesion, scientists have yet to fully understand how the cadherin-catenin-actin complex forms and is regulated. To extend the idea of cell adhesion being like a ‘cellular handshake’, imagine walking along a crowded street while holding hands with a partner. Moving together with the flow of people, navigating obstacles, adjusting your speed and responding to changes in conditions must all be considered if you are to reach your destination without letting go.
Similarly, cells must maintain their adhesion while facing varying stresses and biochemical conditions. Hence, the adhesive structures are regulated and adjusted, via a complex network of structural and regulatory proteins. Where defective adhesion has led to a certain disease it is essential to understand where the problem lies and this requires stepping back and looking at the whole picture.
To better identify the components of this wider network in maintaining and regulating adhesion, researchers at the Mechanobiology Institute, National University of Singapore, applied a combination of experimental and computational techniques to reveal and dissect the complex network of proteins that interact with E-cadherin. To achieve this, E-cadherin was labelled with an enzyme that, when activated, releases a small cloud of a tagging molecule to flag all other proteins in the immediate vicinity. When coupled with quantitative proteomics, this provides a list of proteins interacting with E-cadherin, thus capturing many of the proteins that influence the adhesive properties of the cell.
Overall 561 proteins were found to be associated with E-cadherin, and remarkably 419 of these interactions were completely novel. Using a protein interaction database, the researchers created a map of the E-cadherin interactome that contains information on the function of each protein and its interactions with other proteins within the network. The majority of proteins found were identified as adaptor proteins, which serve as scaffolds within the Adherens Junction. Other proteins involved in cellular transport and protein synthesis were also identified. Interestingly, the researchers found that most of the proteins that associated with E-cadherin did so independently of cell-cell adhesion.
This study highlights that cell adhesion results not only from the formation of a cadherin-catenin-actin complex, but from the activity of more than 500 interacting proteins. Successful cell adhesion requires a cascade of events involving these proteins and any breakdown in this cascade could lead to impaired cell adhesion, and disease. With the E-cadherin interactome now described in detail, researchers can finally step back and view the complex picture that is cell-cell adhesion. This will allow disease related defects to be identified, and new targets researched to understand this vital biological process.
Phone: +65 6516 5125
Amal Naquiah | newswise
First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife
Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
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...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
26.10.2016 | Physics and Astronomy
26.10.2016 | Earth Sciences
25.10.2016 | Earth Sciences