title: FLUCTUATING MOTOR FORCES BEND GROWING MICROTUBULES.
abstract: 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.
authors.affiliation: Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Nandini
authors.initials: N
authors.lastname: Shekhar
authors.forename: Srujana
authors.initials: S
authors.lastname: Neelam
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Anthony Jc
authors.initials: AJ
authors.lastname: Ladd
authors.forename: Richard B
authors.initials: RB
authors.lastname: Dickinson
authors.forename: Tanmay P
authors.initials: TP
authors.lastname: Lele
keywords: Microtubule bending; dynein; myosin
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