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Kinesin-4 KIF21B is a potent microtubule pausing factor

View Article: PubMed Central - PubMed

ABSTRACT

Microtubules are dynamic polymers that in cells can grow, shrink or pause, but the factors that promote pausing are poorly understood. Here, we show that the mammalian kinesin-4 KIF21B is a processive motor that can accumulate at microtubule plus ends and induce pausing. A few KIF21B molecules are sufficient to induce strong growth inhibition of a microtubule plus end in vitro. This property depends on non-motor microtubule-binding domains located in the stalk region and the C-terminal WD40 domain. The WD40-containing KIF21B tail displays preference for a GTP-type over a GDP-type microtubule lattice and contributes to the interaction of KIF21B with microtubule plus ends. KIF21B also contains a motor-inhibiting domain that does not fully block the interaction of the protein with microtubules, but rather enhances its pause-inducing activity by preventing KIF21B detachment from microtubule tips. Thus, KIF21B combines microtubule-binding and regulatory activities that together constitute an autonomous microtubule pausing factor.

Doi:: http://dx.doi.org/10.7554/eLife.24746.001

No MeSH data available.


Related in: MedlinePlus

KIF21B-FL-GFP induces pausing of a depolymerizing MT.The rightmost panel shows tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time (white boxed area in kymograph). See also Supplemental Video 1. Kymograph was generated from a movies acquired using CoolSNAP HQ2 CCD camera (Roper Scientific) with a 1.2-s interval between frames and an exposure time of 100 ms.DOI:http://dx.doi.org/10.7554/eLife.24746.01610.7554/eLife.24746.017Figure 3—Figure Supplement 2—Source Data 1.An excel sheet with numerical data on the quantification of tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time represented as plot in Figure 3—figure supplement 2.DOI:http://dx.doi.org/10.7554/eLife.24746.017
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fig3s2: KIF21B-FL-GFP induces pausing of a depolymerizing MT.The rightmost panel shows tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time (white boxed area in kymograph). See also Supplemental Video 1. Kymograph was generated from a movies acquired using CoolSNAP HQ2 CCD camera (Roper Scientific) with a 1.2-s interval between frames and an exposure time of 100 ms.DOI:http://dx.doi.org/10.7554/eLife.24746.01610.7554/eLife.24746.017Figure 3—Figure Supplement 2—Source Data 1.An excel sheet with numerical data on the quantification of tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time represented as plot in Figure 3—figure supplement 2.DOI:http://dx.doi.org/10.7554/eLife.24746.017

Mentions: 10.7554/eLife.24746.017Figure 3—Figure Supplement 2—Source Data 1.An excel sheet with numerical data on the quantification of tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time represented as plot in Figure 3—figure supplement 2.


Kinesin-4 KIF21B is a potent microtubule pausing factor
KIF21B-FL-GFP induces pausing of a depolymerizing MT.The rightmost panel shows tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time (white boxed area in kymograph). See also Supplemental Video 1. Kymograph was generated from a movies acquired using CoolSNAP HQ2 CCD camera (Roper Scientific) with a 1.2-s interval between frames and an exposure time of 100 ms.DOI:http://dx.doi.org/10.7554/eLife.24746.01610.7554/eLife.24746.017Figure 3—Figure Supplement 2—Source Data 1.An excel sheet with numerical data on the quantification of tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time represented as plot in Figure 3—figure supplement 2.DOI:http://dx.doi.org/10.7554/eLife.24746.017
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC5383399&req=5

fig3s2: KIF21B-FL-GFP induces pausing of a depolymerizing MT.The rightmost panel shows tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time (white boxed area in kymograph). See also Supplemental Video 1. Kymograph was generated from a movies acquired using CoolSNAP HQ2 CCD camera (Roper Scientific) with a 1.2-s interval between frames and an exposure time of 100 ms.DOI:http://dx.doi.org/10.7554/eLife.24746.01610.7554/eLife.24746.017Figure 3—Figure Supplement 2—Source Data 1.An excel sheet with numerical data on the quantification of tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time represented as plot in Figure 3—figure supplement 2.DOI:http://dx.doi.org/10.7554/eLife.24746.017
Mentions: 10.7554/eLife.24746.017Figure 3—Figure Supplement 2—Source Data 1.An excel sheet with numerical data on the quantification of tracked positions of the kinesins and the MT tip together with the fluorescence intensities of the kinesins over time represented as plot in Figure 3—figure supplement 2.

View Article: PubMed Central - PubMed

ABSTRACT

Microtubules are dynamic polymers that in cells can grow, shrink or pause, but the factors that promote pausing are poorly understood. Here, we show that the mammalian kinesin-4 KIF21B is a processive motor that can accumulate at microtubule plus ends and induce pausing. A few KIF21B molecules are sufficient to induce strong growth inhibition of a microtubule plus end in vitro. This property depends on non-motor microtubule-binding domains located in the stalk region and the C-terminal WD40 domain. The WD40-containing KIF21B tail displays preference for a GTP-type over a GDP-type microtubule lattice and contributes to the interaction of KIF21B with microtubule plus ends. KIF21B also contains a motor-inhibiting domain that does not fully block the interaction of the protein with microtubules, but rather enhances its pause-inducing activity by preventing KIF21B detachment from microtubule tips. Thus, KIF21B combines microtubule-binding and regulatory activities that together constitute an autonomous microtubule pausing factor.

Doi:: http://dx.doi.org/10.7554/eLife.24746.001

No MeSH data available.


Related in: MedlinePlus