Recruitment of Polo kinase to the spindle midzone during cytokinesis requires the Feo/Klp3A complex.
BACKGROUND
Polo-like kinases control multiple events during cell division, including mitotic entry, centrosome organization, spindle formation, chromosome segregation and cytokinesis. Their roles during cytokinesis, however, are not well understood because the requirement of these kinases during early stages of mitosis complicates the study of their functions after anaphase onset.


RESULTS
We used time-lapse microscopy to analyze the dynamics of Polo::GFP in Drosophila tissue culture cells during mitosis. After anaphase onset, Polo::GFP concentrated at the spindle midzone, but also diffused along the entire length of the central spindle. Using RNA interference we demonstrate that the microtubule-associated proteins Feo and Klp3A are required for Polo recruitment to the spindle midzone, but not the kinesin Pavarotti as previously thought. Moreover, we show that Feo and Klp3A form a complex and that Polo co-localizes with both proteins during cytokinesis.


CONCLUSIONS
Our results reveal that the Feo/Klp3A complex is necessary for Polo recruitment to the spindle midzone. A similar finding has also been recently reported in mammalian cells [1], suggesting that this basic mechanism has been conserved during evolution, albeit with some differences. Finally, since cleavage furrow formation and ingression are unaffected following feo RNAi, our data imply that Polo recruitment to the central spindle is not required for furrowing, but some other aspect of cytokinesis.
D'Avino
Pier Paolo
PP
Cancer Research UK Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Cambridge, United Kingdom. p.davino@gen.cam.ac.uk
Archambault
Vincent
V
Przewloka
Marcin R
MR
Zhang
Wei
W
Lilley
Kathryn S
KS
Laue
Ernest
E
Glover
David M
DM
D000705:Anaphase / Q000502:physiology; D000818:Animals; D015153:Blotting, Western; D048749:Cytokinesis / Q000502:physiology*; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D016547:Kinesins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D008941:Spindle Apparatus
D029721:Drosophila Proteins; C495328:Feo protein, Drosophila; C093317:Klp3A protein, Drosophila; D008869:Microtubule-Associated Proteins; D034741:RNA, Small Interfering; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C072004:polo protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D016547:Kinesins