Research Project
Grant-in-Aid for Scientific Research (B)
Motility of cytoplasmic dynein has been studied using in vitro microtubule-gliding assay system. Single molecules of dynein stalk head, as well as the stalk fragment composed of stalk head and the coiled-coil region, were observed to attach to the microtubule, move on the microtubule, and then detach from the microtubule. Analysis of the movement revealed to be Brownian motion, suggesting that the binding force of the stalk fragments is weak. Native dynein molecules purified from porcine brain were visualized by binding of the recombinant p150 fragment which contained dynein binding region and fused with gelsolin. In the presence of ATP, single molecules of native dynein did not show processive movement long enough to detect with a regular speed video camera (30fps). However, they behaved differently depending on the nucleotide conditions used. The native dynein molecules sit firmly on microtubules in the presence of AMP-PNP or ADP, and also in the absence of nucleotides. Meanwhile, in the presence of ADP-Vi, they moved around along microtubules very similar way to the movement of the stalk fragments. These results suggest that single molecules of dynein weakly bind to and keep contact with microtubules in ADP-Pi state, and the isolated stalk fragments mimic this state. The microtubule binding fragments of dynactin p150 also showed Brownian motion along microtubules, and the lifetime on microtubules were much longer than those of the stalk fragments and the native dynein molecules. These results show that dynactin p150 can contribute to increase the processivity of dynein movement without disturbing the motility in dynein-dynactin complex.
All 2006 2005 2004
All Journal Article (23 results)
Biochem. Biophys. Res. Commun. 340
Pages: 23-28
Peoc. Natl. Acad. Sci. USA 103
Pages: 5741-5745
Biochem.Biophys.Res.Commun. 340
Proc.Natl Acad.Sci.USA 103
Hum.Mol.Genet. 14
Pages: 3113-3128
J.Biochem. 138
Pages: 95-104
10017346315
Cell Motil. Cytoskeleton 58
Pages: 30-38
J. Biol. Chem. 279
Pages: 22799-22802
EMBO J. 23
Pages: 2459-2467
Pages: 281-289
Biochemistry 43
Pages: 11266-11274
Proc. Natl Acad. Sci. USA 101
Pages: 12865-12869
Cell Motil.Cytoskeleton 58
J.Biol. Chem. 279
Proc.Natl Acad.Sci.USA 101
J.Biol.Chem. 279
Proc.Natl.Acad.Sci.USA 101