Faculty Scientists have made an important discovery about how cells change the strength of the connection between one another to match the various needs of the body.
The team, led by Dr Lydia Tabernero and Prof David Garrod, looked at desmosomes – structures that help to bind two cells together. Specifically, they looked at the desmosomes that are present between two cells in the heart and two cells in the skin.
Desmosomes are known to be specialised for their strong adhesion and this is what allows tissue cells to stick together despite the rigours of everyday life. However, under different situations, like embryonic development and wound healing, these connections would need to become ‘weaker’ in order to allow cells to move and grow. Until this point, scientists have been unable to determine how the desmosomes were able to change their adhesiveness.
The team found that the ‘adaptive strength’ of desmosomes is achieved by special proteins which protrude from the cell. These proteins are the ‘sticky’ points which connect two cells together. They found that the proteins were much more flexible than was previously thought, allowing cells to change the strength of the bond between one another.
To study the role of desmosomes, the team extracted these special proteins to see what they consisted of. They used a combination of different techniques which allowed them to build a computer model of the molecules that make the connections between the cells. They found that the molecules were much more ordered in stronger adhesions than in weaker ones. The molecules were able to change their level of organisation because of their flexibility.
Dr Tabernero comments:
“What is really fascinating about desmosomes is that they become weaker during wound healing and embryonic development, and this weakening is necessary to allow cells to move. In contrast, desmosomes are very strong in adult tissues, particularly in skin and heart. It has been incredibly difficult to work out how they do that but our findings shed new light on this.”
Professor David Garrod has studied desmosomes for decades. He says there are exciting implications for these findings:
“This is the first time that any structural information has been reported for desmosome adhesion. Understanding these cell junctions will be important for future biotechnology applications. We also hope our research will contribute to studies into wound healing, cancer and embryonic development.”
The paper “Cadherin flexibility provides a key difference between desmosomes and adherens junctions” was published in PNAS on April 28th 2015.