AMPK Signaling: Got Food? (IMAGE) Salk Institute Caption In response to energy stress, AMPK, which acts like a gas gauge by sensing how much energy a cell has, puts a damper on cell proliferation. It muffles a cellular protein called raptor (shown in green), which keeps starving cells from dividing. Nuclei are shown in blue and actin, which forms an integral part of the cellular architecture, is shown in red. Credit Image: Courtesy of Dr. Reuben Shaw, Salk Institute for Biological Studies Usage Restrictions News media reproduction to illustrate this story permitted with proper attribution as provided above. For one time use only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.