Kinesin 6 family member Subito participates in mitotic spindle assembly and interacts with mitotic regulators.
Drosophila Subito is a kinesin 6 family member and ortholog of mitotic kinesin-like protein (MKLP2) in mammalian cells. Based on the previously established requirement for Subito in meiotic spindle formation and for MKLP2 in cytokinesis, we investigated the function of Subito in mitosis. During metaphase, Subito localized to microtubules at the center of the mitotic spindle, probably interpolar microtubules that originate at the poles and overlap in antiparallel orientation. Consistent with this localization pattern, subito mutants improperly assembled microtubules at metaphase, causing activation of the spindle assembly checkpoint and lagging chromosomes at anaphase. These results are the first demonstration of a kinesin 6 family member with a function in mitotic spindle assembly, possibly involving the interpolar microtubules. However, the role of Subito during mitotic anaphase resembles other kinesin 6 family members. Subito localizes to the spindle midzone at anaphase and is required for the localization of Polo, Incenp and Aurora B. Genetic evidence suggested that the effects of subito mutants are attenuated as a result of redundant mechanisms for spindle assembly and cytokinesis. For example, subito double mutants with ncd, polo, Aurora B or Incenp mutations were synthetic lethal with severe defects in microtubule organization.
Cesario
Jeff M
JM
Waksman Institute and Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020, USA.
Jang
Janet K
JK
Redding
Bethany
B
Shah
Nishit
N
Rahman
Taslima
T
McKim
Kim S
KS
D000705:Anaphase / Q000502:physiology; D000818:Animals; D064127:Aurora Kinases; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology; D002875:Chromosomes / Q000502:physiology; D048749:Cytokinesis / Q000502:physiology; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D016547:Kinesins / Q000235:genetics / Q000502:physiology*; D007814:Larva; D008677:Metaphase / Q000502:physiology; D008870:Microtubules / Q000502:physiology; D009154:Mutation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000502:physiology; D008941:Spindle Apparatus / Q000502:physiology*
D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; C512039:Incenp protein, Drosophila; C466086:SUB protein, Drosophila; C072004:polo protein, Drosophila; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D016547:Kinesins