26 October 2010
Sean Humphrey has received the $10,000 USD Castle Harlan Award for being the most outstanding early career PhD student at the Garvan Institute in 2010.
The award can be used for anything that might help career development, such as travel to overseas conferences or laboratories.
Castle Harlan Inc. is a US-based private equity firm that wishes to support the kind of medical research being undertaken at Garvan. The award was presented by Mr Leonard Harlan (Chairman, Executive Committee of Castle Harlan) and Mr Howard Morgan (Co-President).
A member of Garvan’s James lab, Sean has been using the latest mass spectrometry technologies to study Type 2 diabetes as a system.
People with Type 2 diabetes do not produce enough insulin, a hormone made in the pancreas that helps convert sugar in the blood into energy in muscles. At the same time, fat and muscle cells become less able to respond to insulin, a phenomenon known as ‘insulin resistance’.
Using the emerging discipline known as ‘proteomics’, Sean screens thousands of proteins, the functional molecules in cells, simultaneously. Investigating muscle and fat cells, he looks at the ways proteins change in direct response to insulin.
“One of the striking things we are seeing is the extent to which cells are regulated by insulin. As many as 15% of the total number of proteins in a cell can be regulated or modulated by insulin at any one time – and that’s a huge percentage,” said Sean.
“When I say that insulin regulates proteins, what I really mean is that it influences the way that proteins talk to each other in a biochemical sense.”
Proteins communicate and modify each other’s behaviour by exchanging phosphate molecules – a process known as phosphorylation.
A protein is not merely functional or non-functional, its functionality can be scaled up or down, depending on phosphorylation, and that can change by the second.
“We have been surprised by the fact that the effects of insulin can be both incredibly rapid and long lasting,” Sean explained.
“So we can see significant changes, thousands of phosphorylation events, throughout the entire cell within seconds of insulin stimulation – and then there are other changes that will only occur after minutes or hours.”
“This tells us that we can’t study biochemical processes at a single point in time – but that we need to follow changes through time to understand the full action of insulin.”
“At the moment, we’re using cell models to interrogate systems to learn as much as we can about how the hormone works. We can then very rapidly take these findings and apply them – using very similar tools and methods – to human tissue samples.”
Sean will be using the Castle Harlan Award to allow him to visit the most advanced proteomics laboratories in the world – such as the lab of Professor Matthias Mann at the Max Planck Institute of Biochemistry in Munich, which he hopes to visit during 2011.