Kinesin-5 Promotes Microtubule Nucleation and Assembly by Stabilizing a Lattice-Competent Conformation of Tubulin

Geng Yuan Chen, Joseph M. Cleary, A. B. Asenjo, Y. Chen, Jacob A. Mascaro, David Florn Johnso Arginteanu, Hernando Sosa, William O. Hancock

Research output: Contribution to journalArticle

Abstract

Besides sliding apart antiparallel microtubules during spindle elongation, the mitotic kinesin-5, Eg5, promotes microtubule polymerization, emphasizing its importance in mitotic spindle length control. Here, we characterize the Eg5 microtubule polymerase mechanism by assessing motor-induced changes in the longitudinal and lateral tubulin-tubulin bonds that form the microtubule lattice. Isolated Eg5 motor domains promote microtubule nucleation, growth, and stability; thus, crosslinking tubulin by pairs of motor heads is not necessary for polymerase activity. Eg5 binds preferentially to microtubules over free tubulin, which contrasts with microtubule-depolymerizing kinesins that preferentially bind free tubulin over microtubules. Colchicine-like inhibitors that stabilize the bent conformation of tubulin allosterically inhibit Eg5 binding, consistent with a model in which Eg5 induces a curved-to-straight transition in tubulin. Domain swap experiments establish that the family-specific loop11-helix 4 junction, which resides near the nucleotide-sensing switch-II domain, is necessary and sufficient for the polymerase activity of Eg5. Thus, we propose a microtubule polymerase mechanism in which Eg5 at the plus-end promotes a curved-to-straight transition in tubulin that enhances lateral bond formation and thereby promotes microtubule growth and stability. One implication is that regulation of Eg5 motile properties by regulatory proteins or small molecule inhibitors could also have effects on intracellular microtubule dynamics. Mitotic kinesin-5 (Eg5) motors promote microtubule polymerization through an unknown mechanism. Chen et al. propose a model in which Eg5 binding to tubulin promotes a curved-to-straight transition that drives microtubule assembly. During mitosis, this polymerase activity may enhance spindle formation and stability and drive poleward flux.

Original languageEnglish (US)
Pages (from-to)2259-2269.e4
JournalCurrent Biology
Volume29
Issue number14
DOIs
StatePublished - Jul 22 2019

Fingerprint

Kinesin
kinesin
Tubulin
tubulin
Microtubules
microtubules
Conformations
Nucleation
Spindle Apparatus
Polymerization
polymerization
Colchicine
Crosslinking
Elongation
mitotic spindle apparatus
Nucleotides
regulatory proteins
colchicine
Switches
Growth

All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Chen, Geng Yuan ; Cleary, Joseph M. ; Asenjo, A. B. ; Chen, Y. ; Mascaro, Jacob A. ; Arginteanu, David Florn Johnso ; Sosa, Hernando ; Hancock, William O. / Kinesin-5 Promotes Microtubule Nucleation and Assembly by Stabilizing a Lattice-Competent Conformation of Tubulin. In: Current Biology. 2019 ; Vol. 29, No. 14. pp. 2259-2269.e4.
@article{c730643b617a4e1ab1174e61059c0182,
title = "Kinesin-5 Promotes Microtubule Nucleation and Assembly by Stabilizing a Lattice-Competent Conformation of Tubulin",
abstract = "Besides sliding apart antiparallel microtubules during spindle elongation, the mitotic kinesin-5, Eg5, promotes microtubule polymerization, emphasizing its importance in mitotic spindle length control. Here, we characterize the Eg5 microtubule polymerase mechanism by assessing motor-induced changes in the longitudinal and lateral tubulin-tubulin bonds that form the microtubule lattice. Isolated Eg5 motor domains promote microtubule nucleation, growth, and stability; thus, crosslinking tubulin by pairs of motor heads is not necessary for polymerase activity. Eg5 binds preferentially to microtubules over free tubulin, which contrasts with microtubule-depolymerizing kinesins that preferentially bind free tubulin over microtubules. Colchicine-like inhibitors that stabilize the bent conformation of tubulin allosterically inhibit Eg5 binding, consistent with a model in which Eg5 induces a curved-to-straight transition in tubulin. Domain swap experiments establish that the family-specific loop11-helix 4 junction, which resides near the nucleotide-sensing switch-II domain, is necessary and sufficient for the polymerase activity of Eg5. Thus, we propose a microtubule polymerase mechanism in which Eg5 at the plus-end promotes a curved-to-straight transition in tubulin that enhances lateral bond formation and thereby promotes microtubule growth and stability. One implication is that regulation of Eg5 motile properties by regulatory proteins or small molecule inhibitors could also have effects on intracellular microtubule dynamics. Mitotic kinesin-5 (Eg5) motors promote microtubule polymerization through an unknown mechanism. Chen et al. propose a model in which Eg5 binding to tubulin promotes a curved-to-straight transition that drives microtubule assembly. During mitosis, this polymerase activity may enhance spindle formation and stability and drive poleward flux.",
author = "Chen, {Geng Yuan} and Cleary, {Joseph M.} and Asenjo, {A. B.} and Y. Chen and Mascaro, {Jacob A.} and Arginteanu, {David Florn Johnso} and Hernando Sosa and Hancock, {William O.}",
year = "2019",
month = "7",
day = "22",
doi = "10.1016/j.cub.2019.05.075",
language = "English (US)",
volume = "29",
pages = "2259--2269.e4",
journal = "Current Biology",
issn = "0960-9822",
publisher = "Cell Press",
number = "14",

}

Kinesin-5 Promotes Microtubule Nucleation and Assembly by Stabilizing a Lattice-Competent Conformation of Tubulin. / Chen, Geng Yuan; Cleary, Joseph M.; Asenjo, A. B.; Chen, Y.; Mascaro, Jacob A.; Arginteanu, David Florn Johnso; Sosa, Hernando; Hancock, William O.

In: Current Biology, Vol. 29, No. 14, 22.07.2019, p. 2259-2269.e4.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Kinesin-5 Promotes Microtubule Nucleation and Assembly by Stabilizing a Lattice-Competent Conformation of Tubulin

AU - Chen, Geng Yuan

AU - Cleary, Joseph M.

AU - Asenjo, A. B.

AU - Chen, Y.

AU - Mascaro, Jacob A.

AU - Arginteanu, David Florn Johnso

AU - Sosa, Hernando

AU - Hancock, William O.

PY - 2019/7/22

Y1 - 2019/7/22

N2 - Besides sliding apart antiparallel microtubules during spindle elongation, the mitotic kinesin-5, Eg5, promotes microtubule polymerization, emphasizing its importance in mitotic spindle length control. Here, we characterize the Eg5 microtubule polymerase mechanism by assessing motor-induced changes in the longitudinal and lateral tubulin-tubulin bonds that form the microtubule lattice. Isolated Eg5 motor domains promote microtubule nucleation, growth, and stability; thus, crosslinking tubulin by pairs of motor heads is not necessary for polymerase activity. Eg5 binds preferentially to microtubules over free tubulin, which contrasts with microtubule-depolymerizing kinesins that preferentially bind free tubulin over microtubules. Colchicine-like inhibitors that stabilize the bent conformation of tubulin allosterically inhibit Eg5 binding, consistent with a model in which Eg5 induces a curved-to-straight transition in tubulin. Domain swap experiments establish that the family-specific loop11-helix 4 junction, which resides near the nucleotide-sensing switch-II domain, is necessary and sufficient for the polymerase activity of Eg5. Thus, we propose a microtubule polymerase mechanism in which Eg5 at the plus-end promotes a curved-to-straight transition in tubulin that enhances lateral bond formation and thereby promotes microtubule growth and stability. One implication is that regulation of Eg5 motile properties by regulatory proteins or small molecule inhibitors could also have effects on intracellular microtubule dynamics. Mitotic kinesin-5 (Eg5) motors promote microtubule polymerization through an unknown mechanism. Chen et al. propose a model in which Eg5 binding to tubulin promotes a curved-to-straight transition that drives microtubule assembly. During mitosis, this polymerase activity may enhance spindle formation and stability and drive poleward flux.

AB - Besides sliding apart antiparallel microtubules during spindle elongation, the mitotic kinesin-5, Eg5, promotes microtubule polymerization, emphasizing its importance in mitotic spindle length control. Here, we characterize the Eg5 microtubule polymerase mechanism by assessing motor-induced changes in the longitudinal and lateral tubulin-tubulin bonds that form the microtubule lattice. Isolated Eg5 motor domains promote microtubule nucleation, growth, and stability; thus, crosslinking tubulin by pairs of motor heads is not necessary for polymerase activity. Eg5 binds preferentially to microtubules over free tubulin, which contrasts with microtubule-depolymerizing kinesins that preferentially bind free tubulin over microtubules. Colchicine-like inhibitors that stabilize the bent conformation of tubulin allosterically inhibit Eg5 binding, consistent with a model in which Eg5 induces a curved-to-straight transition in tubulin. Domain swap experiments establish that the family-specific loop11-helix 4 junction, which resides near the nucleotide-sensing switch-II domain, is necessary and sufficient for the polymerase activity of Eg5. Thus, we propose a microtubule polymerase mechanism in which Eg5 at the plus-end promotes a curved-to-straight transition in tubulin that enhances lateral bond formation and thereby promotes microtubule growth and stability. One implication is that regulation of Eg5 motile properties by regulatory proteins or small molecule inhibitors could also have effects on intracellular microtubule dynamics. Mitotic kinesin-5 (Eg5) motors promote microtubule polymerization through an unknown mechanism. Chen et al. propose a model in which Eg5 binding to tubulin promotes a curved-to-straight transition that drives microtubule assembly. During mitosis, this polymerase activity may enhance spindle formation and stability and drive poleward flux.

UR - http://www.scopus.com/inward/record.url?scp=85069037544&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85069037544&partnerID=8YFLogxK

U2 - 10.1016/j.cub.2019.05.075

DO - 10.1016/j.cub.2019.05.075

M3 - Article

VL - 29

SP - 2259-2269.e4

JO - Current Biology

JF - Current Biology

SN - 0960-9822

IS - 14

ER -