Cul3 (Cullin3)-based E3 ubiquitin ligases recently emerged as critical regulators of mitosis. In this study, we identify two mammalian BTB (Bric-a-brac-Tramtrack-Broad complex)-Kelch proteins, KLHL21 and KLHL22, that interact with Cul3 and are required for efficient chromosome alignment. Interestingly, KLHL21 but not KLHL22 is necessary for cytokinesis and regulates translocation of the chromosomal passenger complex (CPC) from chromosomes to the spindle midzone in anaphase, similar to the previously described BTB-Kelch proteins KLHL9 and KLHL13. KLHL21 directly binds to aurora B and mediates ubiquitination of aurora B in vitro. In contrast to KLHL9 and KLHL13, KLHL21 localizes to midzone microtubules in anaphase and recruits aurora B and Cul3 to this region. Together, our results suggest that different Cul3 adaptors nonredundantly regulate aurora B during mitosis, possibly by ubiquitinating different pools of aurora B at distinct subcellular localizations.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2806313 | PMC |
http://dx.doi.org/10.1083/jcb.200906117 | DOI Listing |
Nat Commun
October 2024
Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Carrer del Dr. Aiguader 88, Barcelona, Spain.
Curr Biol
October 2024
Department of Physics, University of Colorado Boulder, Colorado Avenue, Boulder, CO 80309, USA; Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Colorado Avenue, Boulder, CO 80309, USA. Electronic address:
Kinesin-5 motors play an essential role during mitotic spindle assembly in many organisms: they crosslink antiparallel spindle microtubules, step toward plus ends, and slide the microtubules apart. This activity separates the spindle poles and chromosomes. Kinesin-5s are not only plus-end-directed but can walk or be carried toward MT minus ends, where they show enhanced localization.
View Article and Find Full Text PDFCurr Biol
August 2024
Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA. Electronic address:
The acentrosomal spindle apparatus has kinetochore fibers organized and converged toward opposite poles; however, mechanisms underlying the organization of these microtubule fibers into an orchestrated bipolar array were largely unknown. Kinesin-14D is one of the four classes of Kinesin-14 motors that are conserved from green algae to flowering plants. In Arabidopsis thaliana, three Kinesin-14D members displayed distinct cell cycle-dependent localization patterns on spindle microtubules in mitosis.
View Article and Find Full Text PDFNat Commun
August 2024
Department of Biochemistry and Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA.
Accurate chromosome segregation during cell division relies on coordinated actions of microtubule (MT)-based motor proteins in the mitotic spindle. Kinesin-14 motors play vital roles in spindle assembly and maintenance by crosslinking antiparallel MTs at the spindle midzone and anchoring spindle MTs' minus ends at the poles. In this study, we investigate the force generation and motility of the Kinesin-14 motors HSET and KlpA.
View Article and Find Full Text PDFJ Cell Biol
September 2024
Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA.
At each cell division, nanometer-scale motors and microtubules give rise to the micron-scale spindle. Many mitotic motors step helically around microtubules in vitro, and most are predicted to twist the spindle in a left-handed direction. However, the human spindle exhibits only slight global twist, raising the question of how these molecular torques are balanced.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!