Unravelling the mechanoadhesome of migratory cells
(2019) MOBM02 20192Degree Projects in Molecular Biology
- Abstract
- The ability of a cell to respond to mechanical cues from its external environment is vital for many important cellular processes including directed cell migration, which drives embryogenesis, wound healing and is also a key factor in many diseases such as fibrosis, atherosclerosis and during cancer metastasis. The primary mechanism by which a cell senses and responds to changing mechanical cues from the environment is through changes in the compositional and protein-protein interactions of integrin-based focal adhesions. Focal adhesions (FAs) are large multi-molecular complexes that form a link between the extracellular matrix and the actomyosin cytoskeleton. Previous proteomic studies have generated an adhesome of over 2000 proteins that... (More)
- The ability of a cell to respond to mechanical cues from its external environment is vital for many important cellular processes including directed cell migration, which drives embryogenesis, wound healing and is also a key factor in many diseases such as fibrosis, atherosclerosis and during cancer metastasis. The primary mechanism by which a cell senses and responds to changing mechanical cues from the environment is through changes in the compositional and protein-protein interactions of integrin-based focal adhesions. Focal adhesions (FAs) are large multi-molecular complexes that form a link between the extracellular matrix and the actomyosin cytoskeleton. Previous proteomic studies have generated an adhesome of over 2000 proteins that associate with FA at steady state and a number of studies have revealed the function and response of individual FA proteins in response to force. However, a study of overall compositional changes within FAs in response to mechanical forces is so far lacking. Here, we describe the development of an assay that allows for control of FA formation, application of precise physiologically relevant forces and isolation of the adhesome that forms in response to forces. Using a combination of biochemistry, biophysics, microscopy and mass spectrometry we analysed changes in focal adhesion composition when exposed to mechanical stimulus. We show a significant change in FA composition when force is applied along with increased FA signalling activity. We also identify novel mechanosensory FA proteins that get recruited on force application. Thus, overall, the assay developed and validated in this study provides a platform for the investigation of compositional changes that occur in FAs in response to external mechanical cues and will help discover novel mechanosensors in the future. (Less)
- Popular Abstract
- The Mechanical circuit in cells.
The development and survival of any multicellular organism is controlled by a vast number of cellular and molecular processes. These processes are not random but are instead regulated through signals that come from the outside of the cell, also known as the extracellular environment. These signals can be chemical but often are mechanical. The ability of a cell to translate mechanical signals into information a cell can decipher, is called “mechanotransduction”, and allows a cell to grow, survive and perform specific roles such as healing wounds and protecting the body from infection. There are also a large variety of pathological conditions that occur when there are errors in mechanotransduction... (More) - The Mechanical circuit in cells.
The development and survival of any multicellular organism is controlled by a vast number of cellular and molecular processes. These processes are not random but are instead regulated through signals that come from the outside of the cell, also known as the extracellular environment. These signals can be chemical but often are mechanical. The ability of a cell to translate mechanical signals into information a cell can decipher, is called “mechanotransduction”, and allows a cell to grow, survive and perform specific roles such as healing wounds and protecting the body from infection. There are also a large variety of pathological conditions that occur when there are errors in mechanotransduction including cardiovascular disease, fibrosis and cancer metastasis. It is therefore of great benefit to understand the mechanisms by which a cell is affected by physical forces.
The primary mechanism by which a cell senses mechanical force is through focal adhesions (FA)s. FAs are large multimolecular complexes that form bridges between the extracellular matrix (ECM) and a cells actin cytoskeleton. The ECM is a 3D network of macromolecules that cells sit on, providing both mechanical and biological information from the cell’s surroundings, whereas, the actin cytoskeleton gives the cell structure and allows force to be generated inside the cell. During the development of FAs, a large number of proteins are recruited that relay information from mechanical force between the ECM and the actin cytoskeleton. The forces that are generated from the ECM can vary greatly depending on where in the body the cell is, a stiff ECM for example, such as that surrounding bone, will generate different forces than the ECM of the brain, which is much softer.
While there are many things that are not clearly understood regarding the way that FAs translate mechanical forces into information a cell can use, it is clear that internal and external forces cause changes in its protein composition. While research has been done to investigate individual FA proteins under force, what is missing is an understanding of the total compositional changes that occur in response to mechanical force. We hypothesize that changes in FA composition is one of the ways in which a cell is sensitive to changes in external mechanical force. To investigate this, we have developed an approach that allows us to control and isolate the complete FA complex when external force is applied. To do this we add ECM protein-coated magnetic beads, to mouse cells and apply external force using permeant magnets (Figure 1). We investigated proteins that are known to be more active during FA maturation and also examined compositional changes due to force.
Our findings show that FA activity increases in response to external force, indicating a level of FA maturation. Furthermore, we found that the composition of FAs change dramatically when force is applied. When comparing the data from control data (no force), we saw an increase of more than 500 proteins. This supports the hypothesis that compositional changes in FAs are one way in which a cell is sensitive to changes in external forces.
Master’s Degree Project in Molecular Biology 30 credits 2019
Department of Biology, Lund University
Advisor: Vinay Swaminatham
Laboratory of cell and molecular mechanobiology (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8998921
- author
- Sturgess, Wesley
- supervisor
- organization
- course
- MOBM02 20192
- year
- 2019
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 8998921
- date added to LUP
- 2019-12-20 09:27:52
- date last changed
- 2019-12-20 09:27:52
@misc{8998921,
abstract = {{The ability of a cell to respond to mechanical cues from its external environment is vital for many important cellular processes including directed cell migration, which drives embryogenesis, wound healing and is also a key factor in many diseases such as fibrosis, atherosclerosis and during cancer metastasis. The primary mechanism by which a cell senses and responds to changing mechanical cues from the environment is through changes in the compositional and protein-protein interactions of integrin-based focal adhesions. Focal adhesions (FAs) are large multi-molecular complexes that form a link between the extracellular matrix and the actomyosin cytoskeleton. Previous proteomic studies have generated an adhesome of over 2000 proteins that associate with FA at steady state and a number of studies have revealed the function and response of individual FA proteins in response to force. However, a study of overall compositional changes within FAs in response to mechanical forces is so far lacking. Here, we describe the development of an assay that allows for control of FA formation, application of precise physiologically relevant forces and isolation of the adhesome that forms in response to forces. Using a combination of biochemistry, biophysics, microscopy and mass spectrometry we analysed changes in focal adhesion composition when exposed to mechanical stimulus. We show a significant change in FA composition when force is applied along with increased FA signalling activity. We also identify novel mechanosensory FA proteins that get recruited on force application. Thus, overall, the assay developed and validated in this study provides a platform for the investigation of compositional changes that occur in FAs in response to external mechanical cues and will help discover novel mechanosensors in the future.}},
author = {{Sturgess, Wesley}},
language = {{eng}},
note = {{Student Paper}},
title = {{Unravelling the mechanoadhesome of migratory cells}},
year = {{2019}},
}