Cross-linker design determines microtubule network organization by opposing motors.

Gil Henkin, Wei-Xiang Chew, François Nédélec, Thomas Surrey

Proceedings of the National Academy of Sciences of the United States of America 2022 Aug 16

filter terms:

During cell division, cross-linking motors determine the architecture of the spindle, a dynamic microtubule network that segregates the chromosomes in eukaryotes. It is unclear how motors with opposite directionality coordinate to drive both contractile and extensile behaviors in the spindle. Particularly, the impact of different cross-linker designs on network self-organization is not understood, limiting our understanding of self-organizing structures in cells but also our ability to engineer new active materials. Here, we use experiment and theory to examine active microtubule networks driven by mixtures of motors with opposite directionality and different cross-linker design. We find that although the kinesin-14 HSET causes network contraction when dominant, it can also assist the opposing kinesin-5 KIF11 to generate extensile networks. This bifunctionality results from HSET's asymmetric design, distinct from symmetric KIF11. These findings expand the set of rules underlying patterning of active microtubule assemblies and allow a better understanding of motor cooperation in the spindle.

Citation

Gil Henkin, Wei-Xiang Chew, François Nédélec, Thomas Surrey. Cross-linker design determines microtubule network organization by opposing motors. Proceedings of the National Academy of Sciences of the United States of America. 2022 Aug 16;119(33):e2206398119