Direction and speed of microtubule movements driven by kinesin motors arranged on catchin thick filaments.
Conventional kinesin (Kinesin-1) is a microtubule-based molecular motor that supports intracellular vesicle/organelle transport in various eukaryotic cells. To arrange kinesin motors similarly to myosin motors on thick filaments in muscles, the motor domain of rat conventional kinesin (amino acid residues 1-430) fused to the C-terminal 829 amino acid residues of catchin (KHC430Cat) was bacterially expressed and attached to catchin filaments that can attach to and arrange myosin molecules in a bipolar manner on their surface. Unlike the case of myosin where actin filaments move toward the center much faster than in the opposite direction along the catchin filaments, microtubules moved at the same speed in both directions. In addition, many microtubules moved across the filaments at the same speed with various angles between the axes of the microtubule and catchin filament. Kinesin/catchin chimera proteins with a shorter kinesin neck domain were also prepared. Those without the whole hinge 1 domain and the C-terminal part of the neck helix moved microtubules toward the center of the catchin filaments significantly, but only slightly, faster than in the opposite direction, although the movements in both directions were slower than those of the KHC430Cat construct. The results suggest that kinesin has substantial mechanical flexibility within the motor domain, possibly within the neck linker, enabling its interaction with microtubules having any orientation.
Taba
Toshiki
T
Department of Biology, Graduate School of Sciences, Kyushu University, Fukuoka, Japan.
Edamatsu
Masaki
M
Toba
Shiori
S
Shibata
Keitaro
K
Imafuku
Yasuhiro
Y
Toyoshima
Yoko Yano
YY
Tawada
Katsuhisa
K
Yamada
Akira
A
D000818:Animals; D054443:Cell Migration Assays; D002465:Cell Movement / Q000502:physiology*; D016547:Kinesins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008870:Microtubules / Q000502:physiology* / Q000648:ultrastructure; D018995:Myosin Heavy Chains / Q000737:chemistry / Q000502:physiology*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D013997:Time Factors
D011993:Recombinant Fusion Proteins; C403745:catchin protein, Mytilus galloprovincialis; D018995:Myosin Heavy Chains; D016547:Kinesins