biostudies-literatureShekhar NNIBIB NIH HHSNIGMS NIH HHS120-129https://www.ebi.ac.uk/biostudies/studies/S-EPMC3768200biostudies-literatureUnknown6(2)Despite their rigidity, microtubules in living cells bend significantly during polymerization resulting in greater curvature than can be explained by thermal forces alone. However, the source of the non-thermal forces that bend growing microtubules remains obscure. We analyzed the motion of microtubule tips in NIH-3T3 fibroblasts expressing EGFP-EB1, a fluorescent +TIP protein that specifically binds to the growing ends of microtubules. We found that dynein inhibition significantly reduced the deviation of the growing tip from its initial trajectory. Inhibiting myosin modestly reduced tip fluctuations, while simultaneous myosin and dynein inhibition caused no further decrease in fluctuations compared to dynein inhibition alone. Our results can be interpreted with a model in which dynein linkages play a key role in generating and transmitting fluctuating forces that bend growing microtubules.Cellular and molecular bioengineeringFLUCTUATING MOTOR FORCES BEND GROWING MICROTUBULES.PMC3768200R01 GM102486R01 EB014869Shekhar NWu JDickinson RBNeelam SLele TPLadd AJfalseFLUCTUATING MOTOR FORCES BEND GROWING MICROTUBULES.Despite their rigidity, microtubules in living cells bend significantly during polymerization resulting in greater curvature than can be explained by thermal forces alone. However, the source of the non-thermal forces that bend growing microtubules remains obscure. We analyzed the motion of microtubule tips in NIH-3T3 fibroblasts expressing EGFP-EB1, a fluorescent +TIP protein that specifically binds to the growing ends of microtubules. We found that dynein inhibition significantly reduced the deviation of the growing tip from its initial trajectory. Inhibiting myosin modestly reduced tip fluctuations, while simultaneous myosin and dynein inhibition caused no further decrease in fluctuations compared to dynein inhibition alone. Our results can be interpreted with a model in which dynein linkages play a key role in generating and transmitting fluctuating forces that bend growing microtubules.2013-01-01T00:00:00Z2013 Jun2020-10-29T13:30:53Z2019-03-27T01:15:47ZS-EPMC37682002403963710.1007/s12195-013-0281-z