The preprophase band-associated kinesin-14
OsKCH2 is a processive minus-end-directed
, Pan Wang
, Yuh-Ru Julie Lee
, Joel Bowen
, Allison M. Gicking
, Lijun Guo
& Weihong Qiu
In animals and fungi, cytoplasmic dynein is a processive minus-end-directed motor that plays
dominant roles in various intracellular processes. In contrast, land plants lack cytoplasmic
dynein but contain many minus-end-directed kinesin-14s. No plant kinesin-14 is known to
produce processive motility as a homodimer. OsKCH2 is a plant-speciﬁc kinesin-14 with an
N-terminal actin-binding domain and a central motor domain ﬂanked by two predicted coiled-
coils (CC1 and CC2). Here, we show that OsKCH2 speciﬁcally decorates preprophase band
microtubules in vivo and transports actin ﬁlaments along microtubules in vitro. Importantly,
OsKCH2 exhibits processive minus-end-directed motility on single microtubules as individual
homodimers. We ﬁnd that CC1, but not CC2, forms the coiled-coil to enable OsKCH2
dimerization. Instead, our results reveal that removing CC2 renders OsKCH2 a nonprocessive
motor. Collectively, these results show that land plants have evolved unconventional kinesin-
14 homodimers with inherent minus-end-directed processivity that may function to com-
pensate for the loss of cytoplasmic dynein.
Department of Physics, Oregon State University, Corvallis, OR 97331, USA.
Institute of Photobiophysics, Henan University, Kaifeng 475004 Henan, China.
Department of Plant Biology, University of California at Davis, Davis, CA 95616, USA.
Department of Mathematics, Oregon State University, Corvallis, OR
Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA. These authors contributed equally: Kuo-Fu
Tseng, Pan Wang, Yuh-Ru Julie Lee. Correspondence and requests for materials should be addressed to B.L. (email: BLiu@ucdavis.edu)
or to W.Q. (email: Weihong.Qiu@physics.oregonstate.edu)