CK2 activates kinesin via induction of a conformational change

Abstract

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 nucleotidefree 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.cargo travel | multiple-motor transport | transport regulation

Examining kinesin processivity within a general gating framework

“…Although we stress that our specific findings on kinesin gating, together with the general gating framework presented here, are not based on data from CL mutants, numerous publications have made extensive use of these ( Rice et al, 1999 ; Case et al, 2000 ; Tomishige and Vale, 2000 ; Peterman et al, 2001 ; Rosenfeld et al, 2001 , 2002 ; Sosa et al, 2001 ; Sindelar et al, 2002 ; Asenjo et al, 2003 ; Rice et al, 2003 ; Rosenfeld et al, 2003 ; Naber et al, 2003a , 2003b ; Yildiz et al, 2004 ; Asenjo et al, 2006 ; Milescu et al, 2006 ; Tomishige et al, 2006 ; Mori et al, 2007 ; Sindelar and Downing, 2007 , 2010 ; Verbrugge et al, 2007 ; Dietrich et al, 2008 ; Yildiz et al, 2008 ; Asenjo and Sosa, 2009 ; Toprak et al, 2009 ; Wong et al, 2009 ; Verbrugge et al, 2009a , 2009b , 2009c ; Clancy et al, 2011 ; Naber et al, 2011 ; Mattson-Hoss et al, 2014 ). In light of the unusual behavior displayed by certain CL mutants, it remains to be determined which previous findings are applicable to kinesin in its WT form.…”

As the fat flies: The dynamic lipid droplets of Drosophila embryos

“…GSK-3 is involved in restricting kinesin-1 activity [85], but whether it acts directly and how kinesin-1 is turned off is unclear. As casein-kinase 2 can activate kinesin-1 in vitro [121, 212] and has been detected in droplet preparations [15], it might mediate this regulation. Third, motor coordinators may allow full force production by keeping opposite-polarity motors inactive, as has been proposed for dynactin and Klar [57, 84].…”

“…Finally, lipid droplets in COS-1 cells, fibroblast-like cells derived from African green monkey kidneys, also show active motion, and knockdown of casein kinase 2 (CK-2) severely reduces droplet stall forces, as measured by in-vivo optical trapping [121]. As CK2 can bind to and activate kinesin-1 in vitro [121] (by inducing a conformational change [212]), these observations are consistent with the notion that kinesin-1 also powers droplet transport in COS-1 cells. Proteomic analysis identified CK2 in preparation of purified Drosophila embryonic lipid droplets [15], though its functional significance has not yet been tested.…”

Microtubule C‐Terminal Tails Can Change Characteristics of Motor Force Production

“…While kinesin-family motor domains are relatively conserved, there are still significant differences in the motors kinetic cycles and also their necks and neck-linkers (7)(8)(9)(10)(11)(12)(13)(14), and we are only starting to understand the extent to which molecular variations adapt the motors to their specific functions (see e.g. [15][16][17][18].…”