The spindle checkpoint: tension versus attachment.
The spindle checkpoint ensures the fidelity of chromosome segregation by preventing cell-cycle progression until all the chromosomes make proper bipolar attachments to the mitotic spindle and come under tension. Despite significant advances in our understanding of spindle checkpoint function, the primary signal that activates the spindle checkpoint remains unclear. Whereas some experiments indicate that the checkpoint recognizes the lack of microtubule attachment to the kinetochore, others indicate that the checkpoint senses the absence of tension generated on the kinetochore by microtubules. The interdependence between tension and microtubule attachment make it difficult to determine whether these signals are separable. In this article (which is part of the Chromosome Segregation and Aneuploidy series), we consider recent evidence that supports and opposes the hypothesis that defects in tension act as the primary checkpoint signal.
Pinsky
Benjamin A
BA
Fred Hutchinson Cancer Research Center, Division of Basic Sciences, 1100 Fairview Ave N., PO Box 19024, Seattle, WA 98109, USA.
Biggins
Sue
S
D000818:Animals; D064127:Aurora Kinases; D001696:Biomechanical Phenomena; D018797:Cell Cycle Proteins / Q000502:physiology; D048750:Cell Nucleus Division / Q000502:physiology; D020090:Chromosome Segregation / Q000502:physiology*; D006801:Humans; D018386:Kinetochores / Q000378:metabolism; D008954:Models, Biological; D009687:Nuclear Proteins / Q000502:physiology; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000502:physiology; D044843:SKP Cullin F-Box Protein Ligases / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology; D008941:Spindle Apparatus / Q000502:physiology*
D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C496644:SGO1 protein, human; D029701:Saccharomyces cerevisiae Proteins; C482640:Sgo1 protein, S cerevisiae; D044843:SKP Cullin F-Box Protein Ligases; D011505:Protein-Tyrosine Kinases; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; C093416:MPS1 protein, S cerevisiae