Cell complexity: liquid phase separation (Introduction)

by David Turell , Tuesday, October 06, 2015, 20:39 (3123 days ago) @ David Turell

Oil and water don't mix, but they do in cells:-http://www.sciencedaily.com/releases/2015/09/150924142855.htm-"Proteins are long strings of amino acids that usually fold into specific 3-D structures. hnRNPA1 belongs to a subset of proteins with an amino acid arrangement that prevents folding of one end of the protein, which allows hnRNPA1 to adopt a variety of conformations.-"In this study, researchers showed that under certain conditions related to temperature, salt and protein concentrations, hnRNPA1's disordered tail prompts the protein to condense into liquid droplets through a process called liquid phase separation. The droplets have properties similar to stress granules, including the ability to fuse and grow.-"Liquid phase separation is at work in a wide range of settings, including when oil and vinegar separate in salad dressing. Until recently, however, the process was not believed to play a role in normal cell function. This study is the first to link liquid phase separation to stress granule assembly.-"'It is amazing to find out that proteins like hnRNPA1 have appeared in nature to mediate liquid phase separation under normal physiological conditions," Mittag said. "The long disordered tails in these proteins enable membrane-less compartmentalization in cells. In addition, liquid phase separation is probably important for a whole range of fundamental biological processes.'"-Comment: More and more complexity