Arabidopsis thaliana protein, ATK1, is a minus-end directed kinesin that exhibits non-processive movement.
The microtubule cytoskeleton forms the scaffolding of the meiotic spindle. Kinesins, which bind to microtubules and generate force via ATP hydrolysis, are also thought to play a critical role in spindle assembly, maintenance, and function. The A. thaliana protein, ATK1 (formerly known as KATA), is a member of the kinesin family based on sequence similarity and is implicated in spindle assembly and/or maintenance. Thus, we want to determine if ATK1 behaves as a kinesin in vitro, and if so, determine the directionality of the motor activity and processivity character (the relationship between molecular "steps" and microtubule association). The results show that ATK1 supports microtubule movement in an ATP-dependent manner and has a minus-end directed polarity. Furthermore, ATK1 exhibits non-processive movement along the microtubule and likely requires at least four ATK1 motors bound to the microtubule to support movement. Based on these results and previous data, we conclude that ATK1 is a non-processive, minus-end directed kinesin that likely plays a role in generating forces in the spindle during meiosis.
Department of Biological Sciences, Penn State, 208 Mueller Laboratory, University Park, PA 16802, USA.
Adam I
AI
Marcus
J Christian
JC
Ambrose
Lisa
L
Blickley
William O
WO
Hancock
Richard J
RJ
Cyr
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D020409:Molecular Motor Proteins / Q000235:genetics / Q000378:metabolism; D009038:Motion; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism
C095214:ATK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; C081231:KATA protein, Arabidopsis; D020409:Molecular Motor Proteins; D015534:Trans-Activators; D016547:Kinesins