Structural and Biophysical Characterisation of ESCRT-0

In order to sense and respond to outside events, eukaryotic cells utilise many different proteins on their surface to finely control activities such as growth and movement.

Key to regulating these processes is the uptake of these proteins from the cell surface, and their destruction at the lysosome in a process coordinated by the Endosomal Sorting Complexes Required for Transport (ESCRT) machinery.

The first of these complexes, ESCRT-0, recognises a universal signal (ubiquitin), which is attached to these proteins and marks them for destruction by directing them to the lysosome where they are broken apart and recycled. In order to understand how ESCRT-0 works, we need to know what it looks like.

We intend to investigate this by using the technique cryo-electron microscopy, which will allow us to understand the shape of ESCRT-0 at the atomic level.

We will also use an array of biophysical techniques to investigate how the structure of ESCRT-0 changes when it binds to ubiquitinated proteins, and whether this binding helps to promote the subsequent stages of the ESCRT process. Together, this should tell us what the role of ESCRT-0 is at the head of the ESCRT pathway.