Microtubule-severing ATPases generate internal breaks in microtubules. They are conserved in eukaryotes, and all three known microtubule-severing enzymes, katanin, spastin, and fidgetin, are members of the meiotic subfamily of AAA ATPases. If the newly generated microtubules are stable and regrow, then severing enzymes can act as microtubule amplifiers; if the newly severed microtubules are unstable, severing enzymes can act as depolymerases. Therefore, severing enzymes have the potential to be both positive and negative regulators of microtubule mass, and thus are implicated in regulating microtubule dynamics in a wide range of basic cellular processes ranging from ciliogenesis to cell division, neurogenesis, and phototropism. (Adapted from
PMID:30373906.)
