DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2017 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 5: Single Molecule Biophysics

BP 5.5: Vortrag

Montag, 20. März 2017, 16:15–16:30, HÜL 386

Biased side-stepping enables single molecules of yeast kinesin-8 to avoid roadblocks on microtubulesAniruddha Mitra1,2, •Felix Ruhnow1, and Stefan Diez1,21B CUBE - Center for Molecular Bioengineering, TU Dresden, Germany — 2Center for Advancing Electronics Dresden (cfaed), TU Dresden, Germany

During mitosis, kinesin-8 motors regulate spindle length based on their depolymerization activity at microtubule plus-ends. Remarkably, depolymerization occurs in a length-dependent manner, the underlying mechanism of which has been described by an antenna model where motors bind along the entire lengths of the microtubules and subsequently walk to the plus-ends relying on their extremely high processivity. During such long runs, motors in vivo are expected to frequently encounter roadblocks, such as microtubule-associated proteins. It has therefore been speculated that kinesin-8 motors may use protofilament switching on the microtubules lattice to bypass such obstacles. Whereas recent reports agree that kinesin-8, quite in contrast to kinesin-1, is indeed capable of switching protofilaments, it has not been clear if the underlying side-stepping occurs in a directionally-biased manner. To resolve this controversy, we tracked the 3D-motion of single QD-conjugated kinesin-8 motors stepping along freely suspended microtubules. We observed a spiraling motion with leftward pitches in the order of 1um, indicating that the motors do switch protofilaments in a biased manner. Assays under limiting ATP conditions and in the presence of roadblocks reveal that side-stepping is a robust phenomena, which is not directly coupled to the forward stepping rate.

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2017 > Dresden