Membrane-bound Cdc42 (IMAGE) Stowers Institute for Medical Research Caption Membrane-bound Cdc42 (shown in green) is a key regulator of cell polarity in yeast. A process guided by filaments concentrates Cdc42 molecules in one spot – the spot where the bud will emerge. Credit Image: Courtesy of Sarah Smith, Stowers Institute for Medical Research Usage Restrictions None 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.