Engineering Approaches to Biomolecular Motors

Engineering Approaches to Biomolecular Motors: From in vitro to in vivo Poster Abstracts

37-POS

Board 37

Engineering a Processive Minus End-directed Kinesin-14 for Long-range Transport on

Microtubules

Yuh-Ru Julie Lee

, Kuo-Fu Tseng

, Pan Wang

2,3

, Joel Bowen

, Lijun Guo

Weihong Qiu

2,6

, and

Bo Liu

Department of Plant Biology, University of California, Davis, CA, USA,

Department of Physics,

Oregon State University, Corvallis, OR, USA,

School of Physics and Electronics, Henan

University, Kaifeng, Henan, China,

Department of Mathematics, Oregon State University,

Corvallis, OR, USA,

Department of Biochemistry and Biophysics, Oregon State University,

Corvallis, OR, USA.

Retrograde transport along microtubules in animal and fungal cells is carried out mostly by

cytoplasmic dynein, a minus end-directed motor with high intrinsic processivity. In contrast, land

plants lack cytoplasmic dynein and contain instead a large number of minus end-directed

kinesins. However, none of these minus end-directed kinesins in plants has been found to be

intrinsically processive. We report here that the minus end-directed kinesin OsKCH2 from the

rice plant (Oryza sativa) is intrinsically processive on the microtubule, which is enabled by a

nonmotor domain (CC2) that enhances its affinity for the microtubule. Our findings suggest that

plants have evolved unconventional minus end-directed kinesins as efficient substitutes for

cytoplasmic dynein. Interestingly, substituting CC2 in OsKCH1 – a nonprocessive kinesin-14

from the rice plant – with that from OsKCH2 results in a kinesin-14 chimera (OsKCH1P) that

moves processively on the microtubule. We suggest that OsKCH1P is an important tool for

dissecting the in vivo functional significance of OskCH1 processivity.