Directional Switching of the Kinesin Cin8 Through Motor Coupling

  title={Directional Switching of the Kinesin Cin8 Through Motor Coupling},
  author={Johanna Roostalu and Christian Hentrich and Peter Bieling and Ivo A. Telley and Elmar Schiebel and Thomas Surrey},
  pages={94 - 99}
A molecular motor switches direction upon interacting with individual microtubules or antiparallel microtubules. Kinesin motor proteins are thought to move exclusively in either one or the other direction along microtubules. Proteins of the kinesin-5 family are tetrameric microtubule cross-linking motors important for cell division and differentiation in various organisms. Kinesin-5 motors are considered to be plus-end–directed. However, here we found that purified kinesin-5 Cin8 from budding… 

Molecular motors: Moving in a new direction

Although the budding yeast Kinesin‐5 chromosome instability 8 (Cin8) is plus-end directed when it is working in a group of motors, single Cin8 motors move towards microtubule minus ends, in the opposite direction to that previously thought for wild‐type N‐terminal kinesins.

The yeast kinesin-5 Cin8 interacts with the microtubule in a noncanonical manner

The novel microtubule-binding mode of Cin8 identified here provides a potential explanation for C in8 clustering along microtubules and potentially may contribute to the mechanism for direction reversal.

Regulation of bi-directional movement of single kinesin-5 Cin8 molecules

The evidence points toward cargo regulation of directionality, which is likely to be related to cargo regulation in other kinesins, however, the molecular mechanisms of this regulation remain to be elucidated.

The mitotic kinesin-14 KlpA contains a context-dependent directionality switch

It is shown that KlpA – a mitotic kinesin-14 motor from the filamentous fungus Aspergillus nidulans – contains a context-dependent directionality switch, suggesting that the nonmotor microtubule-binding domain likely acts as a switch for controlling the direction of KlPA motility.

Flexible microtubule anchoring modulates the bi-directional motility of the kinesin-5 Cin8

It is proposed that the largely unstructured L8 facilitates flexible anchoring of Cin8 to the MTs, which enables the direct observation of bi-directional motility in motility assays.

The Kinesin-5 Tail Domain Directly Modulates the Mechanochemical Cycle of the Motor for Anti-Parallel Microtubule Sliding

A revised microtubule-sliding model is suggested, in which tail domains directly engage motor domains at both ends of kinesin-5 homotetramers enhancing stability of the dual microtubules-bound states leading to slow motility yet high force production.

Mechanisms by Which Kinesin-5 Motors Perform Their Multiple Intracellular Functions

The recently discovered bidirectional motility in fungi kinesin-5 motors is described, and its possible physiological relevance is discussed.

Mitotic kinesins in action: diffusive searching, directional switching, and ensemble coordination

Findings demonstrate how various properties of kinesin-5 and -14 motors—diffusive searching, directional switching, and multivalent interactions—allow them to achieve their physiological roles of cross-linking parallel microtubules and sliding antiparallel ones during cell division.



Determinants of kinesin motor polarity.

The neck-motor junction was critical for Ncd minus-end movement; attachment of the neck to the stalk may also play a role; residues or regions contributing to motor polarity must be present in both the Ncd neck and the kinesin motor core.

The bipolar mitotic kinesin Eg5 moves on both microtubules that it crosslinks

It is shown that the vertebrate kinesin-5 Eg5 drives the sliding of microtubules depending on their relative orientation, and in controlled in vitro assays that Eg5 has the remarkable capability of simultaneously moving at ∼20 nm s-1 towards the plus-ends of each of the two microtubule it crosslinks.

Microtubule cross-linking triggers the directional motility of kinesin-5

Eg5, the vertebrate kinesin-5, has two modes of motion: an adenosine triphosphate–dependent directional mode and a diffusive mode that does not require ATP hydrolysis, and single-molecule experiments are used to examine how the switching between these modes is controlled.

A bipolar kinesin

KRP130, a homotetrameric BimC-related kinesin purified from Drosophila melanogaster embryos, has an unusual ultrastructure that is analogous to a miniature myosin filament in a bipolar 'minifilament' of microtubules.

Reversal in the direction of movement of a molecular motor

A chimaera composed of the motor domain of the minus-end-directed kinesin of Neurospora crassa is reported on, demonstrating that the polarity of force generation of the ncd motor domain has been reversed and that the direction of microtubule movement is not controlled solely by the motordomain.

Allosteric inhibition of kinesin-5 modulates its processive directional motility

Eg5 is a processive kinesin whose motility includes, in addition to ATP-dependent directional motion, a diffusive component not requiring ATP hydrolysis, and these data will impact these inhibitors' use as probes and development as chemotherapeutic agents.

Processive kinesins require loose mechanical coupling for efficient collective motility

It is found that kinesin‐1 constructs that lack most of the non‐motor sequence slow each other down when collectively transporting a microtubule, depending on the number of interacting motors.

Plus end-specific depolymerase activity of Kip3, a kinesin-8 protein, explains its role in positioning the yeast mitotic spindle

The role of Kip3p is explained in positioning the mitotic spindle in budding yeast and potentially other processes controlled by kinesin-8 family members, which are required for microtubule–cortical interactions, normal spindle assembly and kinetochore dynamics.