The kinesin-5 tail domain directly modulates the mechanochemical cycle of the motor domain for anti-parallel microtubule sliding

• Published in: eLife Vol. 9
• Main Authors: Bodrug, Tatyana, Wilson-Kubalek, Elizabeth M, Nithianantham, Stanley, Thompson, Alex F, Alfieri, April, Gaska, Ignas, Major, Jennifer, Debs, Garrett, Inagaki, Sayaka, Gutierrez, Pedro, Gheber, Larisa, McKenney, Richard J, Sindelar, Charles Vaughn, Milligan, Ronald, Stumpff, Jason, Rosenfeld, Steven S, Forth, Scott T, Al-Bassam, Jawdat
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 20.01.2020; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Adenosine Diphosphate - metabolism; Adenosine Triphosphate - metabolism; Cell Biology; Cryoelectron Microscopy; Humans; Hydrolysis; Kinesin; kinesin-5; Kinesins - chemistry; Kinesins - metabolism; Kinesins - ultrastructure; Kinetics; Localization; Microtubule; Microtubules; Microtubules - metabolism; mitosis; mitotic spindle; Motility; motor protein; Protein Binding; Protein Domains; sliding; Spindle Apparatus - metabolism; Spindles; Structural Biology and Molecular Biophysics; sliding; cell biology; motor protein; kinesin-5; structural biology; Microtubule; D. melanogaster; mitosis; molecular biophysics; human; mitotic spindle
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.51131

Kinesin-5 motors organize mitotic spindles by sliding apart microtubules. They are homotetramers with dimeric motor and tail domains at both ends of a bipolar minifilament. Here, we describe a regulatory mechanism involving direct binding between tail and motor domains and its fundamental role in microtubule sliding. Kinesin-5 tails decrease microtubule-stimulated ATP-hydrolysis by specifically engaging motor domains in the nucleotide-free or ADP states. Cryo-EM reveals that tail binding stabilizes an open motor domain ATP-active site. Full-length motors undergo slow motility and cluster together along microtubules, while tail-deleted motors exhibit rapid motility without clustering. The tail is critical for motors to zipper together two microtubules by generating substantial sliding forces. The tail is essential for mitotic spindle localization, which becomes severely reduced in tail-deleted motors. Our studies suggest a revised microtubule-sliding model, in which kinesin-5 tails stabilize motor domains in the microtubule-bound state by slowing ATP-binding, resulting in high-force production at both homotetramer ends.