Definition of "microtubule" [microtubule]

• Any of the proteinaceous cylindrical hollow structures that are distributed throughout the cytoplasm of eukaryotic cells, providing structural support and assisting in cellular locomotion and transport. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The common view was that microtubules all began at the cell body; the graph should have simply shown a decrease in microtubule number as one looked further from the cell body."
• "John Sulston had already found that these cells had unique bundles of very prominent microtubules (the cells were originally called the microtubule cells), so they were very easy to see in the micrographs."
• "Marching along a microtubule is the kinesin motor, the hero of our story, carrying a huge sack of proteins to be delivered to a pre-determined place in the cell."