Researchers at Columbia University, in collaboration with biologists in Baylor College of Medicine, have made a significant step in understanding and imaging protein synthesis, pinpointing exactly where and when cells produce new proteins. Assistant Professor Wei Min’s team developed a new technique to produce high-resolution imaging of newly synthesized proteins inside living cells. The findings were published in the July 9th issue of The Proceedings of the National Academy of Sciences(Volume 110; Issue 28).
Proteins carry out almost every crucial biological function. Synthesis of new proteins is a key step in gene expression and is a major process by which cells respond rapidly to environmental cues in physiological and pathological conditions, such as cancer, autism and oxidative stress. A cell’s proteome (i.e., the sum of all the cell’s proteins) is highly dynamic and tightly regulated by both protein synthesis and disposal to maintain homeostasis and ensure normal functioning of the body. Many intricate biological processes, such as cell growth, differentiation and diseases, involve new protein synthesis at a specific location and time. In particular, long-lasting neuronal plasticity (changes in neural pathways and synapses that come from alterations in behavior, environment and bodily injury), such as those underlying learning and long-term memory, require new protein synthesis in a site- and time- dependent manner inside neurons.
Min and colleagues’ new technique harnesses deuterium (a heavier cousin of the normal hydrogen atom), which was first discovered by Harold Urey in 1932, also at Columbia University. When hydrogen is replaced by deuterium, the biochemical activities of amino acids change very little. When added to growth media for culturing cells, these deuterium-labeled amino acids are incorporated by the natural cell machineries as the necessary building blocks for new protein production. Hence, only newly synthesized proteins by living cells will carry the special deuterium atoms connected to carbon atoms. The carbon-deuterium bonds vibrate at a distinct frequency, different from almost all natural chemical bonds existing inside cells.
Read more at: Phys.org