PT  - JOURNAL ARTICLE
AU  - Kuo-Fu Tseng
AU  - Pan Wang
AU  - Yuh-Ru Julie Lee
AU  - Joel Bowen
AU  - Allison M. Gicking
AU  - Lijun Guo
AU  - Bo Liu
AU  - Weihong Qiu
TI  - The preprophase band-associated kinesin-14 OsKCH2 is a processive minus-end-directed microtubule motor
AID  - 10.1101/232652
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 232652
4099  - http://biorxiv.org/content/early/2017/12/11/232652.short
4100  - http://biorxiv.org/content/early/2017/12/11/232652.full
AB  - In animals and fungi, cytoplasmic dynein is a processive 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 for OsKCH2 dimerization. Instead, CC2 functions to enable OsKCH2 processivity by enhancing its binding to microtubules. Collectively, these results show that land plants have evolved unconventional kinesin-14 homodimers with inherent minus-end-directed processivity that may function to compensate for the loss of cytoplasmic dynein.