Document Detail


Force-dependent detachment of kinesin-2 biases track switching at cytoskeletal filament intersections.
MedLine Citation:
PMID:  22828331     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Intracellular trafficking of organelles often involves cytoskeletal track switching. Organelles such as melanosomes are transported by multiple motors including kinesin-2, dynein, and myosin-V, which drive switching between microtubules and actin filaments during dispersion and aggregation. Here, we used optical trapping to determine the unitary and ensemble forces of kinesin-2, and to reconstitute cargo switching at cytoskeletal intersections in a minimal system with kinesin-2 and myosin-V motors bound to beads. Single kinesin-2 motors exerted forces up to ∼5 pN, similar to kinesin-1. However, kinesin-2 motors were more likely to detach at submaximal forces, and the duration of force maintenance was short as compared to kinesin-1. In multimotor assays, force increased with kinesin-2 density but was not affected by the presence of myosin-V. In crossed filament assays, switching frequencies of motor-bound beads were dependent on the starting track. At equal average forces, beads tended to switch from microtubules onto overlying actin filaments consistent with the relatively faster detachment of kinesin-2 at near-maximal forces. Thus, in addition to relative force, switching probability at filament intersections is determined by the dynamics of motor-filament interaction, such as the quick detachment of kinesin-2 under load. This may enable fine-tuning of filament switching in the cell.
Authors:
Harry W Schroeder; Adam G Hendricks; Kazuho Ikeda; Henry Shuman; Vladimir Rodionov; Mitsuo Ikebe; Yale E Goldman; Erika L F Holzbaur
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Biophysical journal     Volume:  103     ISSN:  1542-0086     ISO Abbreviation:  Biophys. J.     Publication Date:  2012 Jul 
Date Detail:
Created Date:  2012-07-25     Completed Date:  2012-12-10     Revised Date:  2013-07-12    
Medline Journal Info:
Nlm Unique ID:  0370626     Medline TA:  Biophys J     Country:  United States    
Other Details:
Languages:  eng     Pagination:  48-58     Citation Subset:  IM    
Copyright Information:
Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.
Affiliation:
Pennsylvania Muscle Institute and Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
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MeSH Terms
Descriptor/Qualifier:
Actin Cytoskeleton / chemistry,  physiology*
Animals
Kinesin / chemistry,  physiology*
Microscopy, Fluorescence
Microtubules / physiology*
Molecular Dynamics Simulation
Myosin Type V / chemistry,  physiology
Protein Conformation
Rabbits
Xenopus
Xenopus Proteins / chemistry,  physiology*
Grant Support
ID/Acronym/Agency:
GM062290/GM/NIGMS NIH HHS; GM071339/GM/NIGMS NIH HHS; GM087253/GM/NIGMS NIH HHS; GM089077/GM/NIGMS NIH HHS; R01 GM062290/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/XKLP3 protein, Xenopus; 0/Xenopus Proteins; EC 3.6.1.-/Kinesin; EC 3.6.1.-/Myosin Type V
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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