Microtubules (image) Rice University Share Print E-Mail Caption Rice University scientists are using custom software to help explain the dynamic instability seen at all times in microtubules, essential elements of a cell's cytoskeleton. The individual elements are protein dimers attached to either guanosine triphosphate (GTP) in red or guanosine diphosphate (GDP) in blue. Clusters of GTP-binding molecules serve as caps that slow or stop microtubules from dissolving. Credit Xin Li/Rice University Usage Restrictions None Share Print E-Mail 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.