Drosophila katanin is a microtubule depolymerase that regulates cortical-microtubule plus-end interactions and cell migration

Dong Zhang. et al. NATURE cell biology (2011) 13, 361–370

Speaker: Yung-Han Yang (楊詠涵)                                 Time: 15:00~16:00, Apr. 11, 2011

Commentator: Dr. Liang-Yi Hung (洪良宜 老師)        Place: Room 601

Abstract

Microtubules are a component of the cytoskeleton required for cell motility, intracellular transport, and mitosis/meiosis. Regulation of microtubule dynamics at the cell cortex is important and largely unknown. Katanin is a heterodimer of p60, a member of AAA family of ATPases with microtubule-severing activities, and p80, a protein with WD40 repeats, which are frequently involved in protein–protein interactions. Drosophila katanin (Dm-Kat60) concentrates at the cell cortex of S2 Drosophila cells during interphase, where it suppresses the polymerization of microtubule plus-ends. In Dm-Kat60 RNAi cells, microtubule cytoskeleton becomes aberrantly dense cortical arrays ringing around nucleus. In migratory D17 Drosophila cells, katanin also localizes at the leading edge and serves as a negative regulator of cell motility by suppressing fast and persistent migration with time lapse microscopy.  Studies in vitro, Dm-Kat60 severs and depolymerizes microtubules from their ends which is different from peeling mode by Kinesin 13 family. Base on these data, Dm-Kat60 has the capacity to function both as a microtubule-severing enzyme and a microtubule end depolymerase. The findings of this study uncover unexpected roles for the Drosophila katanin p60 Dm-Kat60 in the regulation of cortical microtubule dynamics and provide insights into how the microtubule cytoskeleton affects cell migration.

References

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2.      Vito Mennella., et al. 2005. Functionally distinct kinesin-13 family members cooperate to regulate microtubule dynamics during interphase. NATURE cell biology, Vol. 5, 235-245