Cytoskeleton: Treadmilling & Dynamic instability
English for Biologists• Dynamic instability
Microfilaments and microtubules are highly dynamic. Both have the ability to rapidly disassemble and reassemble in a new way, towards a new destination. This process is called dynamic instability and it is more common in microtubules. It manifests itself by periods of persistent microtubule growth interrupted by occasional switching to rapid shrinkage (often dubbed microtubule "catastrophe"), and then by switching back from shrinkage to growth (called microtubule "rescue"). During these events microtubules disassociate into their components - tubulin proteins.
• Treadmilling
Interestingly, if one end of the microfilament is constantly being disassembled and the opposite end is constantly being built upon, it appears that a section of this microfilament “moves” across the stratum in cytosol. This phenomenon is called treadmilling and is considered to be intrinsic to microfilaments, although it can be observed in microtubules as well.
