Australian scientists have charted the path of insulin action in cells in precise detail like never before. This provides a comprehensive blueprint for understanding what goes wrong in diabetes.
The breakthrough study, conducted by Sean Humphrey and Professor David James from Sydney's Garvan Institute of Medical Research, is now published in the early online edition of the prestigious journal Cell Metabolism.
First discovered in 1921, the insulin hormone plays a very important role in the body because it helps us lower blood sugar after a meal, by enabling the movement of sugar from the blood into cells. Until now, although scientists have understood the purpose of insulin at a broad level, they have struggled to understand exactly how it achieves its task.
The latest analytical devices called mass spectrometers now provide the tool that has been missing the means of looking into the vastly complex molecular maze that exists in every single cell in the human body.
These powerful devices have opened up a field known as 'proteomics', the study of proteins on a very large scale. Proteins represent the working parts of cells, using energy to perform all essential functions such as muscle contraction, heartbeat or even memory.
Each cell houses multiple copies of between 10,000 and 12,000 protein types, which communicate with each other using various methods, the most common of which is a process known as 'phosphorylation'. Phosphate molecules are deliberately added to proteins in order to convey information, or else change the protein's function.
Each of the protein types in a cell has up to 20 potential 'phosphorylation sites', regions to which a phosphate molecule can be added. This pushes the total number of possible cell states from one moment to the next into the billions.
The authors discovered 37,248 phosphorylation sites on 5,705 different proteins, 15% of which changed in response to i
|Contact: Alison Heather|
Garvan Institute of Medical Research