A UC Berkeley team finds that knocking out a key gene, DNA-PK, prevents weight gain from carbs. Imagine you've bellied up to the all-you-can-eat pasta bar in Berkeley, only to meet one of the mice from Hei Sook Sul's Nutritional Science and Toxicology Lab. If you come here often, you know that loading up on carbohydrates is going to make you pretty chubby. But you notice that your fellow diner -- the mouse -- is pretty slim. How does he do it?
The gene involved, known as DNA-PK (for DNA-dependent protein kinase), is widely studied for its role in repairing breaks in the DNA -- a function that has made it crucial in cancer research and treatment. But Sul said it was a surprise to discover that the same gene has a key role in the liver's conversion of excess glucose (all that bread, pasta and sugary soda you've failed to work off) to fatty acids. Not only were mice whose DNA-PK gene had been knocked out 40% leaner than normal mice when all were fed a high-carb, low-fat diet; they also had better blood-lipid profiles, suggesting they'd be at lower risk of developing heart disease.