The non-processive rice kinesin-14 OsKCH1 transports actin filaments aloril microtubuler with two distinct velocities

Microtubules and actin filaments function coordinately in many cellular processes(1-3). Although much of this Coordination is mediated by proteins that statically bridge the two cytoskeletal networks(4-6), kinesin-14 motor; with an actin binding caiponin homology domain (KCHs) have been discovered as putatively dynamic crosslinkers piants(7,8). OsKCH1, KCH from rice, interacts with both71:microtubules and actin filaments in vivo and in vitro However, remained unclear whether this interaction binding rethces or even abniishos the motor's molity rnicrotuimiosY) Here, we directly show in vitro that Osi(Ciri is a non-processive minusend -directed motor that transports actin filaments along microtubules: interestingly we observe two distinct transport velocities dependent on the relative orientation of the actin filaments with respect to the microtuhules: in torsional cortmliance rneznAiremontL on molecules reveal low flexibility in 0.sKCH1,. We suggest that the orientation-dependent transport velocities emerge from OsKall's low torsional compliance combined with an inherently oriented binding to the actin filament. Together, our results imply a C1 ntral role of OsIKCH1 in the our orientation of actin filaments along microtubules, and thus a contribution to the organization of the cytoskeicial architecture.