Slk19-dependent mid-anaphase pause in kinesin-5-mutated cells.
We examined spindle elongation in anaphase in Saccharomyces cerevisiae cells mutated for the kinesin-5 motor proteins Cin8 and Kip1. Cells were deleted for KIP1 and/or expressed one of two motor-domain Cin8 mutants (Cin8-F467A or Cin8-R196K, which differ in their ability to bind microtubules in vitro, with Cin8-F467A having the weakest ability). We found that, in kinesin-5-mutated cells, predominantly in kip1 Delta cin8-F467A cells, anaphase spindle elongation was frequently interrupted after the fast phase, resulting in a mid-anaphase pause. Expression of kinesin-5 mutants also caused an asymmetric midzone location and enlarged midzone size, suggesting that proper organization of the midzone is required for continuous spindle elongation. We also examined the effects of components of the FEAR pathway, which is involved in the early-anaphase activation of Cdc14 regulatory phosphatase, on anaphase spindle elongation in kip1 Delta cin8-F467A cells. Deletion of SLK19, but not SPO12, eliminated the mid-anaphase pause, caused premature anaphase onset and defects in DNA division during anaphase, and reduced viability in these cells. Finally, overriding of the pre-anaphase checkpoint by overexpression of Cdc20 also eliminated the mid-anaphase pause and caused DNA deformation during anaphase in kip1 Delta cin8-F467A cells. We propose that transient activation of the pre-anaphase checkpoint in kinesin-5-mutated cells induces a Slk19-dependent mid-anaphase pause, which might be important for proper DNA segregation.
Movshovich
Natalia
N
Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Fridman
Vladimir
V
Gerson-Gurwitz
Adina
A
Shumacher
Inbal
I
Gertsberg
Irena
I
Fich
Alexander
A
Hoyt
M Andrew
MA
Katz
Benjamin
B
Gheber
Larisa
L
D000705:Anaphase / Q000235:genetics* / Q000502:physiology; D002478:Cells, Cultured; D016547:Kinesins; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism*; D008954:Models, Biological; D020409:Molecular Motor Proteins; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism
C075342:CIN8 protein, S cerevisiae; C431747:KIP1 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C437104:Slk19 protein, S cerevisiae; C499614:spo12 protein, S pombe; D016547:Kinesins