CK2 activates kinesin via induction of a conformational change.
Kinesin is the canonical plus-end microtubule motor and has been the focus of intense study since its discovery in 1985. We previously demonstrated a time-dependent inactivation of kinesin in vitro that was fully reversible by the addition of purified casein kinase 2 (CK2) and showed that this inactivation/reactivation pathway was relevant in cells. Here we show that kinesin inactivation results from a conformational change that causes the neck linker to be positioned closer to the motor domain. Furthermore, we show that treatment of kinesin with CK2 prevents and reverses this repositioning. Finally, we demonstrate that CK2 treatment facilitates ADP dissociation from the motor, resulting in a nucleotide-free state that promotes microtubule binding. Thus, we propose that kinesin inactivation results from neck-linker repositioning and that CK2-mediated reactivation results from CK2's dual ability to reverse this repositioning and to promote ADP release.
Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, CA 92697; and.
Michelle K
MK
Mattson-Hoss
Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Yamato
Y
Niitani
Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, CA 92697; and.
Elizabeth A
EA
Gordon
Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, CA 92697; and.
Yonggun
Y
Jun
Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, CA 92697; and.
Lee
L
Bardwell
Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Michio
M
Tomishige
Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, CA 92697; and sgross@uci.edu.
Steven P
SP
Gross
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D047390:Casein Kinase II / Q000737:chemistry* / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology; D006801:Humans; D016547:Kinesins / Q000737:chemistry* / Q000378:metabolism*; D008870:Microtubules / Q000502:physiology; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000502:physiology*
D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D047390:Casein Kinase II; D016547:Kinesins
cargo travel; multiple-motor transport; transport regulation