Structural highlights
Function
[KTNA1_CAEEL] Catalytic subunit of a complex which severs microtubules in an ATP-dependent manner. Microtubule severing may promote rapid reorganization of cellular microtubule arrays. Required specifically for meiotic spindle formation in the female germline; the presence of this protein is inimical to the formation of mitotic spindles (PubMed:8027178, PubMed:10809666, PubMed:12885567). In body wall muscles, regulates organization of myosin thick filaments (PubMed:22621901).[HAMAP-Rule:MF_03023][1] [2] [3] [4]
Publication Abstract from PubMed
The AAA ATPase katanin severs microtubules. It is critical in cell division, centriole biogenesis, and neuronal morphogenesis. Its mutation causes microcephaly. The microtubule templates katanin hexamerization and activates its ATPase. The structural basis for these activities and how they lead to severing is unknown. Here, we show that beta-tubulin tails are necessary and sufficient for severing. Cryoelectron microscopy (cryo-EM) structures reveal the essential tubulin tail glutamates gripped by a double spiral of electropositive loops lining the katanin central pore. Each spiral couples allosterically to the ATPase and binds alternating, successive substrate residues, with consecutive residues coordinated by adjacent protomers. This tightly couples tail binding, hexamerization, and ATPase activation. Hexamer structures in different states suggest an ATPase-driven, ratchet-like translocation of the tubulin tail through the pore. A disordered region outside the AAA core anchors katanin to the microtubule while the AAA motor exerts the forces that extract tubulin dimers and sever the microtubule.
Katanin Grips the beta-Tubulin Tail through an Electropositive Double Spiral to Sever Microtubules.,Zehr EA, Szyk A, Szczesna E, Roll-Mecak A Dev Cell. 2019 Nov 8. pii: S1534-5807(19)30854-8. doi:, 10.1016/j.devcel.2019.10.010. PMID:31735665[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Srayko M, Buster DW, Bazirgan OA, McNally FJ, Mains PE. MEI-1/MEI-2 katanin-like microtubule severing activity is required for Caenorhabditis elegans meiosis. Genes Dev. 2000 May 1;14(9):1072-84. PMID:10809666
- ↑ Yang HY, McNally K, McNally FJ. MEI-1/katanin is required for translocation of the meiosis I spindle to the oocyte cortex in C elegans. Dev Biol. 2003 Aug 1;260(1):245-59. PMID:12885567
- ↑ Wilson KJ, Qadota H, Mains PE, Benian GM. UNC-89 (obscurin) binds to MEL-26, a BTB-domain protein, and affects the function of MEI-1 (katanin) in striated muscle of Caenorhabditis elegans. Mol Biol Cell. 2012 Jul;23(14):2623-34. doi: 10.1091/mbc.E12-01-0055. Epub 2012, May 23. PMID:22621901 doi:http://dx.doi.org/10.1091/mbc.E12-01-0055
- ↑ Clark-Maguire S, Mains PE. Localization of the mei-1 gene product of Caenorhaditis elegans, a meiotic-specific spindle component. J Cell Biol. 1994 Jul;126(1):199-209. PMID:8027178
- ↑ Zehr EA, Szyk A, Szczesna E, Roll-Mecak A. Katanin Grips the beta-Tubulin Tail through an Electropositive Double Spiral to Sever Microtubules. Dev Cell. 2019 Nov 8. pii: S1534-5807(19)30854-8. doi:, 10.1016/j.devcel.2019.10.010. PMID:31735665 doi:http://dx.doi.org/10.1016/j.devcel.2019.10.010
