The complex interplay between the neck and hinge domains in kinesin-1 dimerization and motor activity.
Kinesin-1 dimerizes via the coiled-coil neck domain. In contrast to animal kinesins, neck dimerization of the fungal kinesin-1 NcKin requires additional residues from the hinge. Using chimeric constructs containing or lacking fungal-specific elements, the proximal part of the hinge was shown to stabilize the neck coiled-coil conformation in a complex manner. The conserved fungal kinesin hinge residue W384 caused neck coiled-coil formation in a chimeric NcKin construct, including parts of the human kinesin-1 stalk. The stabilizing effect was retained in a NcKinW384F mutant, suggesting important pi-stacking interactions. Without the stalk, W384 was not sufficient to induce coiled-coil formation, indicating that W384 is part of a cluster of several residues required for neck coiled-coil folding. A W384-less chimera of NcKin and human kinesin possessed a non-coiled-coil neck conformation and showed inhibited activity that could be reactivated when artificial interstrand disulfide bonds were used to stabilize the neck coiled-coil conformation. On the basis of yeast two-hybrid data, we propose that the proximal hinge can bind kinesin's cargo-free tail domain and causes inactivation of kinesin by disrupting the neck coiled-coil conformation.
Bathe
Friederike
F
Department of Cell Biology, Adolf-Butenandt-Institute, University of Munich, D-80336 Munich, Germany.
Hahlen
Katrin
K
Dombi
Renate
R
Driller
Lucia
L
Schliwa
Manfred
M
Woehlke
Guenther
G
D000595:Amino Acid Sequence; D017124:Conserved Sequence; D019281:Dimerization; D004220:Disulfides / Q000378:metabolism; D006801:Humans; D016547:Kinesins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009492:Neurospora crassa / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011392:Proline / Q000235:genetics / Q000378:metabolism; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013329:Structure-Activity Relationship; D014364:Tryptophan / Q000235:genetics / Q000378:metabolism
D004220:Disulfides; D014364:Tryptophan; D011392:Proline; D016547:Kinesins