A direct interaction between cytoplasmic dynein and kinesin I may coordinate motor activity.
Cytoplasmic dynein and kinesin I are both unidirectional intracellular motors. Dynein moves cargo toward the cell center, and kinesin moves cargo toward the cell periphery. There is growing evidence that bi-directional motility is regulated in the cell, potentially through direct interactions between oppositely oriented motors. We have identified a direct interaction between cytoplasmic dynein and kinesin I. Using the yeast two-hybrid assay and affinity chromatography, we demonstrate that the intermediate chain of dynein binds to kinesin light chains 1 and 2. The interaction is both direct and specific. Co-immunoprecipitation experiments demonstrate an interaction between endogenous proteins in rat brain cytosol. Double-label immunocytochemistry reveals a partial co-localization of vesicle-associated motor proteins. Together these observations suggest that soluble motors can interact, potentially allowing kinesin I to actively localize dynein to cellular sites of function. There is also a vesicle population with both dynein and kinesin I bound that may be capable of bi-directional motility along cellular microtubules.
Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6085, USA.
Lee A
LA
Ligon
Mariko
M
Tokito
Jeffrey M
JM
Finklestein
Francesca E
FE
Grossman
Erika L F
EL
Holzbaur
D000818:Animals; D001921:Brain; D002460:Cell Line; D002465:Cell Movement; D003593:Cytoplasm / Q000737:chemistry*; D022162:Cytoplasmic Vesicles / Q000737:chemistry; D004398:Dyneins / Q000378:metabolism* / Q000502:physiology; D004847:Epithelial Cells / Q000737:chemistry / Q000648:ultrastructure; D006801:Humans; D016547:Kinesins / Q000378:metabolism* / Q000502:physiology; D051379:Mice; D008870:Microtubules / Q000737:chemistry; D020409:Molecular Motor Proteins / Q000378:metabolism* / Q000502:physiology; D011485:Protein Binding; D025941:Protein Interaction Mapping; D021381:Protein Transport; D051381:Rats
D020409:Molecular Motor Proteins; D004398:Dyneins; D016547:Kinesins