Structural highlights
Function
KTNB1_MOUSE Participates in a complex which severs microtubules in an ATP-dependent manner. May act to target the enzymatic subunit of this complex to sites of action such as the centrosome. Microtubule severing may promote rapid reorganization of cellular microtubule arrays and the release of microtubules from the centrosome following nucleation. Microtubule release from the mitotic spindle poles may allow depolymerization of the microtubule end proximal to the spindle pole, leading to poleward microtubule flux and poleward motion of chromosome. Microtubule release within the cell body of neurons may be required for their transport into neuronal processes by microtubule-dependent motor proteins. This transport is required for axonal growth.[HAMAP-Rule:MF_03022]
Publication Abstract from PubMed
ASPM (known as Asp in fly and ASPM-1 in worm) is a microcephaly-associated protein family that regulates spindle architecture, but the underlying mechanism is poorly understood. Here, we show that ASPM forms a complex with another protein linked to microcephaly, the microtubule-severing ATPase katanin. ASPM and katanin localize to spindle poles in a mutually dependent manner and regulate spindle flux. X-ray crystallography revealed that the heterodimer formed by the N- and C-terminal domains of the katanin subunits p60 and p80, respectively, binds conserved motifs in ASPM. Reconstitution experiments demonstrated that ASPM autonomously tracks growing microtubule minus ends and inhibits their growth, while katanin decorates and bends both ends of dynamic microtubules and potentiates the minus-end blocking activity of ASPM. ASPM also binds along microtubules, recruits katanin and promotes katanin-mediated severing of dynamic microtubules. We propose that the ASPM-katanin complex controls microtubule disassembly at spindle poles and that misregulation of this process can lead to microcephaly.
Microtubule minus-end regulation at spindle poles by an ASPM-katanin complex.,Jiang K, Rezabkova L, Hua S, Liu Q, Capitani G, Maarten Altelaar AF, Heck AJR, Kammerer RA, Steinmetz MO, Akhmanova A Nat Cell Biol. 2017 May;19(5):480-492. doi: 10.1038/ncb3511. Epub 2017 Apr 24. PMID:28436967[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Jiang K, Rezabkova L, Hua S, Liu Q, Capitani G, Maarten Altelaar AF, Heck AJR, Kammerer RA, Steinmetz MO, Akhmanova A. Microtubule minus-end regulation at spindle poles by an ASPM-katanin complex. Nat Cell Biol. 2017 May;19(5):480-492. doi: 10.1038/ncb3511. Epub 2017 Apr 24. PMID:28436967 doi:http://dx.doi.org/10.1038/ncb3511
