Measuring Molecular Motor Forces In Vivo: Implications for Tug-of-War Models of Bidirectional Transport

Leidel, Christina; Longoria, Rafael A.; Gutierrez, Franciso Marquez; Shubeita, George T.

doi:10.1016/j.bpj.2012.06.038

Cited by 130 publications

(209 citation statements)

References 54 publications

Supporting

Mentioning

177

Contrasting

Unclassified

Order By: Relevance

“…Similar "memory" has recently also been shown for lipid droplets in optical manipulation experiments (24). These studies showed that after pulling the lipid droplet off the microtubule by optical tweezers and allowing it to reattach, the majority of lipid droplets continued to move in the same direction.…”

Section: Conclusion and Discussionsupporting

confidence: 69%

Correlative live-cell and superresolution microscopy reveals cargo transport dynamics at microtubule intersections

Bálint

Vilanova

Álvarez

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

200

230

View full text Add to dashboard Cite

Intracellular transport plays an essential role in maintaining the organization of polarized cells. Motor proteins tether and move cargos along microtubules during long-range transport to deliver them to their proper location of function. To reach their destination, cargo-bound motors must overcome barriers to their forward motion such as intersection points between microtubules. The ability to visualize how motors navigate these barriers can give important information about the mechanisms that lead to efficient transport. Here, we first develop an all-optical correlative imaging method based on single-particle tracking and superresolution microscopy to map the transport trajectories of cargos to individual microtubules with high spatiotemporal resolution. We then use this method to study the behavior of lysosomes at microtubulemicrotubule intersections. Our results show that the intersection poses a significant hindrance that leads to long pauses in transport only when the separation distance of the intersecting microtubules is smaller than ∼100 nm. However, the obstructions are typically overcome by the motors with high fidelity by either switching to the intersecting microtubule or eventually passing through the intersection. Interestingly, there is a large tendency to maintain the polarity of motion (anterograde or retrograde) after the intersection, suggesting a high degree of regulation of motor activity to maintain transport in a given direction. These results give insights into the effect of the cytoskeletal geometry on cargo transport and have important implications for the mechanisms that cargo-bound motors use to maneuver through the obstructions set up by the complex cytoskeletal network.C ells rely on a two-way transport system to deliver important proteins and organelles to their location of function. Kinesin and dynein motors are responsible for long-range transport along microtubules (1). Although dynein walks toward the (−) end of the microtubule (retrograde), carrying cargo toward the cell nucleus, most kinesins walk toward the (+) end (anterograde), carrying cargo toward the cell periphery (1). Microtubules organize into a complex, 3D network inside cells, and the intersections between microtubule filaments or between microtubules and other cytoskeletal filaments (actin, intermediate filaments) likely have important consequences on the efficiency and accuracy of cargo transport (2). For example, microtubule-microtubule intersections can serve as switching points or barriers that disrupt continuous transport in a given direction.The effect of microtubule-microtubule intersections on the movement of individual motors and motor-decorated beads has been studied using in vitro reconstituted microtubules deposited on top of each other (3, 4). These studies showed that although single motors can have varied behavior (passing, dissociation, switching), at high motor densities dynein-decorated beads stop and tether at the intersection (3). On the basis of these results, it was suggested that microtubul...

show abstract

Section: Conclusion and Discussionsupporting

confidence: 69%

Correlative live-cell and superresolution microscopy reveals cargo transport dynamics at microtubule intersections

Bálint

Vilanova

Álvarez

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

200

230

View full text Add to dashboard Cite

show abstract

“…Thus, our current result provides a strong support for the idea that besides its binding to other subunits, the tail is important for regulating dynein motor function in vivo. It is worth pointing out that in vivo, the dynein motor carrying a cargo not only needs to move in a cytoplasm with considerable viscosity (63,64) but also needs to compete with plus-end-directed motors bound to the same cargo (65)(66)(67). In filamentous fungi, kinesin-3 is able to bind to the dynein-bound early endosome and be carried to the minus end as a cargo of dynein (40,53,68).…”

Section: Discussionmentioning

confidence: 99%

Identification of a Novel Site in the Tail of Dynein Heavy Chain Important for Dynein Function in Vivo

Qiu

Zhang

Xiang

2013

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background:The dynein heavy chain tail is required for subunit interactions but not for in vitro motility. Results: A dynein tail mutation affects dynein function in vivo without affecting subunit interactions. Conclusion: A site upstream of the subunit interaction sites of the dynein tail is important in vivo. Significance: This study discovers a novel site of the dynein tail critical for motor function in vivo.

show abstract

“…Some authors [215] report for example that stall forces are completely different in vivo, and in particular that they become similar for dyneins and kinesins [223] (which have quite different stall forces in vitro). The origin of these differences are so far not understood.…”

Section: In Vitro Versus In Vivomentioning

confidence: 99%

“…Experimental evidence for the attachment of many motors is based on a number of observations, in particular based on force measurements [345,351,215,223]. Another argument is that, for several motor-cargo systems, there is evidence for bidirectional non diffusive motion [388].…”

Section: Motor-cargo Complexesmentioning

confidence: 99%

Intracellular transport driven by cytoskeletal motors: General mechanisms and defects

2015

View full text Add to dashboard Cite

Cells are the elementary units of living organisms, which are able to carry out many vital functions. These functions rely on active processes on a microscopic scale. Therefore, they are strongly out-of-equilibrium systems, which are driven by continuous energy supply. The tasks that have to be performed in order to maintain the cell alive require transportation of various ingredients, some being small, others being large. Intracellular transport processes are able to induce concentration gradients and to carry objects to specific targets. These processes cannot be carried out only by diffusion, as cells may be crowded, and quite elongated on molecular scales. Therefore active transport has to be organized.The cytoskeleton, which is composed of three types of filaments (microtubules, actin and intermediate filaments), determines the shape of the cell, and plays a role in cell motion. It also serves as a road network for a special kind of vehicles, namely the cytoskeletal motors. These molecules can attach to a cytoskeletal filament, perform directed motion, possibly carrying along some cargo, and then detach.It is a central issue to understand how intracellular transport driven by molecular motors is regulated. The interest for this type of question was enhanced when it was discovered that intracellular transport breakdown is one of the signatures of some neuronal diseases like the Alzheimer.We give a survey of the current knowledge on microtubule based intracellular transport. Our review includes on the one hand an overview of biological facts, obtained from experiments, and on the other hand a presentation of some modeling attempts based on cellular automata. We present some background knowledge on the original and variants of the TASEP (Totally Asymmetric Simple Exclusion Process), before turning to more application oriented models. After addressing microtubule based transport in general, with a focus on in vitro experiments, and on cooperative effects in the transportation of large cargos by multiple motors, we concentrate on axonal transport, because of its relevance for neuronal diseases. Some important characteristics of axonal transport is that it takes place in a confined environment; Besides several types of motors are involved, that move in opposite directions. It is a challenge to understand how this bidirectional transport is organized. We review several features that could contribute to the efficiency of bidirectional transport in the axon, including in particular the role of motor-motor interactions and of the dynamics of the underlying microtubule network. Finally, we also discuss some open questions that may be relevant for future research in this field.

show abstract

Measuring Molecular Motor Forces In Vivo: Implications for Tug-of-War Models of Bidirectional Transport

Cited by 130 publications

References 54 publications

Correlative live-cell and superresolution microscopy reveals cargo transport dynamics at microtubule intersections

Correlative live-cell and superresolution microscopy reveals cargo transport dynamics at microtubule intersections

Identification of a Novel Site in the Tail of Dynein Heavy Chain Important for Dynein Function in Vivo

Intracellular transport driven by cytoskeletal motors: General mechanisms and defects

Contact Info

Product

Resources

About