The Dundee team were looking for a protein that activates AMPK, an enzyme that reduces blood glucose levels and is a target for drugs commonly used in treating Type 2 diabetes.

They hoped that this protein would be a target for new anti-diabetes drugs, and their search ended with an enzyme called LKB1. Surprisingly, a lack of LKB1 is a known cause of Peutz-Jeghers syndrome, in which the risk of developing some cancers is 15 times higher than normal.

"It was totally unexpected," said Dario Alessi, one of the research team leaders. "LKB1 was thought of as a tumour suppressor gene, and AMPK was involved in diabetes. No one thought that there could be a link between the two."

Grahame Hardie, the second team leader, said: "The idea that LKB1 might switch on AMPK came from work I did on a related system in the simple single-cell organism brewer's yeast. [] The idea that LKB1 might be the key was a genuine 'Eureka' moment, especially when I realised that Dario Alessi already worked on it and had all of the expertise necessary to test the idea."

Having identified the LKB1 enzyme in yeast, the Dundee team looked for its counterpart in rat liver extracts that could activate AMPK. They not only identified the rat version of LKB1, but also found two proteins that bind to LKB1 and enhance its activity. When the researchers removed LKB1 from the extract, they found that the extract could no longer activate AMPK, consistent with LKB1 being the activating enzyme.

LKB1 normally acts to prevent tumour growth. The way that it does this was unclear until now, but this research suggests that its tumour-preventing properties may be dependent o
'"/>

Contact: Gemma Bradley
press@biomedcentral.com
44-207-323-0323
BioMed Central
24-Sep-2003