The processes involved in the heart’s response to stress

Structure and protein-protein interaction of the Popeye domain containing proteins

‘Popeye’ proteins are a newly discovered group of molecules in the outer surface of the cell, the cell membrane. They play a role in helping the heart rate to change in response to stress by interacting with other proteins (channels and pumps), which control how heart cells respond to electrical signals. Popeye proteins can also sense the levels of ‘messenger molecules’ which are produced in stress situations and increase the activity of other proteins that also increase the heart rate. We know that faults in the genes that produce Popeye proteins are linked with heart rhythm disorders, or arrhythmias, but scientists don’t fully understand how these proteins work. The BHF has awarded a grant to Professor Thomas Brand and his team at Imperial College London to work out the molecular structure of the Popeye protein and the proteins it interacts with – its ‘molecular network’. They will then block these interactions and find out what effect this has. This research will give us a better understanding of the structure of Popeye proteins, what they do and what other factors control them. Understanding how the heart adapts to stress may reveal new ways to treat patients suffering from heart failure, or arrhythmias.