From the Cover: Detection of fractional steps in cargo movement by the collective operation of kinesin-1 motors

@article{LeducC_multipleKinesinsInVitro_PNAS_2007, abstract = {The stepping behavior of single kinesin-1 motor proteins has been studied in great detail. However, in cells, these motors often do not work alone but rather function in small groups when they transport cellular cargo. Until now, the cooperative interactions between motors in such groups were poorly understood. A fundamental question is whether two or more motors that move the same cargo step in synchrony, producing the same step size as a single motor, or whether the step size of the cargo movement varies. To answer this question, we performed in vitro gliding motility assays, where microtubules coated with quantum dots were driven over a glass surface by a known number of kinesin-1 motors. The motion of individual microtubules was then tracked with nanometer precision. In the case of transport by two kinesin-1 motors, we found successive 4-nm steps, corresponding to half the step size of a single motor. Dwell-time analysis did not reveal any coordination, in the sense of alternate stepping, between the motors. When three motors interacted in collective transport, we identified distinct forward and backward jumps on the order of 10 nm. The existence of the fractional steps as well as the distinct jumps illustrate a lack of synchronization and has implications for the analysis of motor-driven organelle movement investigated in vivo. 10.1073/pnas.0701864104}, author = {Leduc, Cecile and Ruhnow, Felix and Howard, Jonathon and Diez, Stefan }, citeulike-article-id = {2443060}, doi = {10.1073/pnas.0701864104}, journal = {Proceedings of the National Academy of Sciences}, keywords = {howard, in, kinesin, mootrs, motor, multiple, vitro}, month = {June}, number = {26}, pages = {10847--10852}, posted-at = {2008-05-27 10:56:00}, priority = {0}, title = {From the Cover: Detection of fractional steps in cargo movement by the collective operation of kinesin-1 motors}, url = {http://dx.doi.org/10.1073/pnas.0701864104}, volume = {104}, year = {2007} }

TY - JOUR ID - LeducC_multipleKinesinsInVitro_PNAS_2007 L3 - citeulike-article-id:2443060 TI - From the Cover: Detection of fractional steps in cargo movement by the collective operation of kinesin-1 motors JF - Proceedings of the National Academy of Sciences VL - 104 IS - 26 SP - 10847 EP - 10852 N2 - The stepping behavior of single kinesin-1 motor proteins has been studied in great detail. However, in cells, these motors often do not work alone but rather function in small groups when they transport cellular cargo. Until now, the cooperative interactions between motors in such groups were poorly understood. A fundamental question is whether two or more motors that move the same cargo step in synchrony, producing the same step size as a single motor, or whether the step size of the cargo movement varies. To answer this question, we performed in vitro gliding motility assays, where microtubules coated with quantum dots were driven over a glass surface by a known number of kinesin-1 motors. The motion of individual microtubules was then tracked with nanometer precision. In the case of transport by two kinesin-1 motors, we found successive 4-nm steps, corresponding to half the step size of a single motor. Dwell-time analysis did not reveal any coordination, in the sense of alternate stepping, between the motors. When three motors interacted in collective transport, we identified distinct forward and backward jumps on the order of 10 nm. The existence of the fractional steps as well as the distinct jumps illustrate a lack of synchronization and has implications for the analysis of motor-driven organelle movement investigated in vivo. 10.1073/pnas.0701864104 KW - howard KW - in KW - kinesin KW - mootrs KW - motor KW - multiple KW - vitro AU - Leduc, Cecile AU - Ruhnow, Felix AU - Howard, Jonathon AU - Diez, Stefan PY - 2007/06/26/ UR - http://dx.doi.org/10.1073/pnas.0701864104 ER -