Microtubules are important as structural proteins. They may be used to support the cell, as pathways for the movement of motor proteins, and to ensure the even division of chromosomal material during mitosis

Question

Thus, having the ability to regulate the growth of these proteins is necessary for survival. Discuss some of the ways in which microtubule growth can be regulated.

What will be an ideal response?

Answer 1

Answer: One of the most basic methods of control is supplying the necessary building blocks for making microtubules. When concentrations of tubulin are low, microtubules tend to shrink. When the concentration is high, their length increases. At concentrations between critical levels, the length stays the same. Even when there is sufficient tubulin, growth is controlled in other ways. GTP is bound to the end of β-tubulin. While it remains a whole GTP, growth continues but when it is hydrolyzed, the length actually decreases. Lastly, there are microtubule-associated proteins (MAPs) which are a large group of proteins capable of destabilizing and stabilizing microtubule length. They can also regulate ways in which the microtubules interact with each other and the cell. In ectothermic organisms, temperature can also affect formation.