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Navigation Strategies of Motor Proteins on Decorated Tracks.

Bertalan Z, Budrikis Z, La Porta CA, Zapperi S - PLoS ONE (2015)

Bottom Line: Here, we show by numerical simulations that deterministic and random motor steps yield different outcomes when random obstacles decorate the microtubule tracks: kinesin moves faster on clean tracks but its motion is strongly hindered on decorated tracks, while dynein is slower on clean tracks but more efficient in avoiding obstacles.Further simulations indicate that dynein's advantage on decorated tracks is due to its ability to step backwards.Our results explain how different navigation strategies are employed by the cell to optimize motor driven cargo transport.

View Article: PubMed Central - PubMed

Affiliation: Institute for Scientific Interchange Foundation, Torino, Italy.

ABSTRACT
Motor proteins display widely different stepping patterns as they move on microtubule tracks, from the deterministic linear or helical motion performed by the protein kinesin to the uncoordinated random steps made by dynein. How these different strategies produce an efficient navigation system needed to ensure correct cellular functioning is still unclear. Here, we show by numerical simulations that deterministic and random motor steps yield different outcomes when random obstacles decorate the microtubule tracks: kinesin moves faster on clean tracks but its motion is strongly hindered on decorated tracks, while dynein is slower on clean tracks but more efficient in avoiding obstacles. Further simulations indicate that dynein's advantage on decorated tracks is due to its ability to step backwards. Our results explain how different navigation strategies are employed by the cell to optimize motor driven cargo transport.

No MeSH data available.


Related in: MedlinePlus

When kinesin is allowed to take backwards steps its obstacle navigational abilities increase drastically.The effect is especially dramatic for large decoration fraction ρ. When kinesin can take backwards steps with the same probability pbck = 0.2 as wild-type dynein, for ρ > 0.15 the backwards-stepping kinesin is faster than wild-type dynein. Lines are guides to the eye; errorbars are smaller than the symbol size.
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pone.0136945.g007: When kinesin is allowed to take backwards steps its obstacle navigational abilities increase drastically.The effect is especially dramatic for large decoration fraction ρ. When kinesin can take backwards steps with the same probability pbck = 0.2 as wild-type dynein, for ρ > 0.15 the backwards-stepping kinesin is faster than wild-type dynein. Lines are guides to the eye; errorbars are smaller than the symbol size.

Mentions: As well as being able to take off-axis steps in both directions, dynein is different from kinesin in that it can step backwards. To illuminate the role of these backwards steps, we have simulated a modified kinesin model in which the walker can take a small fraction of its steps backwards. As shown in Fig 7, this increases its abilities to navigate a decorated track substantially. Indeed, for large ρ > 0.15, backward-stepping kinesin moves faster even than wild-type dynein. This suggests that the relevant aspect of dynein’s advantage over wild-type kinesin at large decoration fraction is its backwards stepping, rather than stochasticity in the off-axis steps.


Navigation Strategies of Motor Proteins on Decorated Tracks.

Bertalan Z, Budrikis Z, La Porta CA, Zapperi S - PLoS ONE (2015)

When kinesin is allowed to take backwards steps its obstacle navigational abilities increase drastically.The effect is especially dramatic for large decoration fraction ρ. When kinesin can take backwards steps with the same probability pbck = 0.2 as wild-type dynein, for ρ > 0.15 the backwards-stepping kinesin is faster than wild-type dynein. Lines are guides to the eye; errorbars are smaller than the symbol size.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556374&req=5

pone.0136945.g007: When kinesin is allowed to take backwards steps its obstacle navigational abilities increase drastically.The effect is especially dramatic for large decoration fraction ρ. When kinesin can take backwards steps with the same probability pbck = 0.2 as wild-type dynein, for ρ > 0.15 the backwards-stepping kinesin is faster than wild-type dynein. Lines are guides to the eye; errorbars are smaller than the symbol size.
Mentions: As well as being able to take off-axis steps in both directions, dynein is different from kinesin in that it can step backwards. To illuminate the role of these backwards steps, we have simulated a modified kinesin model in which the walker can take a small fraction of its steps backwards. As shown in Fig 7, this increases its abilities to navigate a decorated track substantially. Indeed, for large ρ > 0.15, backward-stepping kinesin moves faster even than wild-type dynein. This suggests that the relevant aspect of dynein’s advantage over wild-type kinesin at large decoration fraction is its backwards stepping, rather than stochasticity in the off-axis steps.

Bottom Line: Here, we show by numerical simulations that deterministic and random motor steps yield different outcomes when random obstacles decorate the microtubule tracks: kinesin moves faster on clean tracks but its motion is strongly hindered on decorated tracks, while dynein is slower on clean tracks but more efficient in avoiding obstacles.Further simulations indicate that dynein's advantage on decorated tracks is due to its ability to step backwards.Our results explain how different navigation strategies are employed by the cell to optimize motor driven cargo transport.

View Article: PubMed Central - PubMed

Affiliation: Institute for Scientific Interchange Foundation, Torino, Italy.

ABSTRACT
Motor proteins display widely different stepping patterns as they move on microtubule tracks, from the deterministic linear or helical motion performed by the protein kinesin to the uncoordinated random steps made by dynein. How these different strategies produce an efficient navigation system needed to ensure correct cellular functioning is still unclear. Here, we show by numerical simulations that deterministic and random motor steps yield different outcomes when random obstacles decorate the microtubule tracks: kinesin moves faster on clean tracks but its motion is strongly hindered on decorated tracks, while dynein is slower on clean tracks but more efficient in avoiding obstacles. Further simulations indicate that dynein's advantage on decorated tracks is due to its ability to step backwards. Our results explain how different navigation strategies are employed by the cell to optimize motor driven cargo transport.

No MeSH data available.


Related in: MedlinePlus