Force generation of KIF1C is impaired by pathogenic mutations

Siddiqui, Nida; Röth, Daniel; Toleikis, Algirdas; Zwetsloot, Alexander J.; Cross, Robert A.; Straube, Anne

doi:10.1016/j.cub.2022.07.029

“…This would potentially allow KIF1C to act as a processivity factor. However, it is unlikely that the biophysical properties of the motor alone is sufficient to explain the absence of tug-of-war in DDHK complexes, because the related kinesin-3 KIF1A has an even higher propensity for backslipping 56 , but when truncated KIF1A was coupled to dynein using a DNA-based linker, the majority of complexes showed little net velocity 33 . Comparing the plus end-directed movement of DDHK complexes containing full-length dynein with those assembled with the dynein tail (DTDHK), shows a moderate reduction in speed (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…This indicates that dynein is also in a conformation that causes resistance but does not stall plus-end movement. A fully engaged dynein-dynactin-HOOK3 complex has an average stall force of about 5 pN 21 , whereas only 1 pN resisting force is needed to reduce KIF1C velocity by half 56 . Therefore, during plus end-directed runs of DDHK complexes, dynein engages only weakly with microtubules to keep the resisting force below 1 pN, which is about half of the stall force of a dynein dimer 31 .…”

Section: Discussionmentioning

confidence: 99%

KIF1C activates and extends dynein movement through the FHF cargo adaptor

Ali,

Zwetsloot,

Stone

et al. 2023

Preprint

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Cellular cargos move bidirectionally on microtubules due to the presence of opposite polarity motors dynein and kinesin. Many studies show these motors are co-dependent, whereby one requires the activity of the other, although the mechanism is unknown. Here, using in vitro motility assays, we show that the kinesin-3 KIF1C acts both as an activator and a processivity factor for dynein. Activation only requires a fragment of the non-motor tail of KIF1C (KIF1C-stalk) to bind the cargo adaptor HOOK3. Cryo-EM, crosslinking mass spectrometry and AlphaFold2 predictions reveal this binding site to be separate from that of two constitutive factors (FTS and FHIP), which link HOOK3 to small G-proteins on cargos. We provide a structural model for how the FTS-HOOK3-FHIP1B (FHF) complex is auto-inhibited and explain how the KIF1C-stalk relieves this inhibition. Collectively, our work provides a molecular explanation for co-dependency by revealing that the mutual activation of dynein and kinesin is mediated through their shared adaptor. Many adaptors bind both dynein and kinesins, suggesting this mechanism could be generalised to other bidirectional complexes.

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“…This explains how the presence of KIF1C can reduce dynein's velocity but not stall it as it would if it were fully engaged. Our previous optical trapping experiments showed that KIF1C tends to slip backwards under load rather than fully detach from the microtubule 56 . This would potentially allow KIF1C to act as a processivity factor.…”

Section: Discussionmentioning

confidence: 96%

“…This indicates that dynein is also in a conformation that causes resistance but does not stall plus-end movement. A fully engaged dynein-dynactin-HOOK3 complex has an average stall force of about 5 pN 21 , whereas only 1 pN resisting force is needed to reduce KIF1C velocity by half 56 . Therefore, during plus end-directed runs of DDHK complexes, dynein engages only weakly with microtubules to keep the resisting force below 1 pN, which is about half of the stall force of a dynein dimer 31 .…”

Section: Discussionmentioning

confidence: 99%

KIF1C activates and extends dynein movement through the FHF cargo adaptor

Straube,

Ali,

Zwetsloot

et al. 2023

Preprint

Self Cite

0

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Cellular cargos move bidirectionally on microtubules due to the presence of opposite polarity motors dynein and kinesin. Many studies show these motors are co-dependent, whereby one requires the activity of the other, although the mechanism is unknown. Here, using in vitro motility assays, we show that the kinesin-3 KIF1C acts both as an activator and a processivity factor for dynein. Activation only requires a fragment of the non-motor tail of KIF1C (KIF1C-stalk) to bind the cargo adaptor HOOK3. Cryo-EM, crosslinking mass spectrometry and AlphaFold2 predictions reveal this binding site to be separate from that of two constitutive factors (FTS and FHIP), which link HOOK3 to small G-proteins on cargos. We provide a structural model for how the FTS-HOOK3-FHIP1B (FHF) complex is auto-inhibited and explain how the KIF1C-stalk relieves this inhibition. Collectively, our work provides a molecular explanation for co-dependency by revealing that the mutual activation of dynein and kinesin is mediated through their shared adaptor. Many adaptors bind both dynein and kinesins, suggesting this mechanism could be generalised to other bidirectional complexes.

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“…Typically, processive kinesin motors generate forces of 1 pN or more 37,[44][45][46] . However, we have shown that KlpA's processivity depends on its N-terminal MT-binding tail, as removal of this tail abolishes its ability to move processively 17 .…”

Section: Discussionmentioning

confidence: 99%

Kinesin-14 HSET and KlpA are non-processive microtubule motors with load-dependent power strokes

Gennerich

¹

,

Liu

²

,

Rao

³

et al. 2023

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Accurate chromosome segregation during cell division relies on coordinated actions of microtubule (MT)-based motor proteins in the mitotic spindle. Kinesin-14 motors play vital roles in spindle assembly and maintenance by crosslinking antiparallel MTs at the spindle midzone and anchoring spindle MTs' minus ends at the poles. We investigate the force generation and motility of the Kinesin-14 motors HSET and KlpA, revealing that both motors function as non-processive motors under load, producing single power strokes per MT encounter. Each homodimeric motor generates forces of ~0.5 pN, but when assembled in teams, they cooperate to generate forces of 1 pN or more. Importantly, cooperative activity among multiple motors leads to increased MT-sliding velocities. Our findings deepen our understanding of the structure-function relationship of Kinesin-14 motors and underscore the significance of cooperative behavior in their cellular functions.

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Force generation of KIF1C is impaired by pathogenic mutations

Cited by 7 publications

References 37 publications

KIF1C activates and extends dynein movement through the FHF cargo adaptor

KIF1C activates and extends dynein movement through the FHF cargo adaptor

KIF1C activates and extends dynein movement through the FHF cargo adaptor

Kinesin-14 HSET and KlpA are non-processive microtubule motors with load-dependent power strokes

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