scholarly journals KNL1 facilitates phosphorylation of outer kinetochore proteins by promoting Aurora B kinase activity

2013 ◽  
Vol 203 (6) ◽  
pp. 957-969 ◽  
Author(s):  
Gina V. Caldas ◽  
Keith F. DeLuca ◽  
Jennifer G. DeLuca
Keyword(s):  
Kinase Activity ◽  
Aurora B ◽  
Wild Type ◽  
Aurora B Kinase ◽  
Kinetochore Protein ◽  
Anaphase Onset ◽  
N Terminus ◽  
Late Mitosis ◽  
Early Mitosis

Aurora B kinase phosphorylates kinetochore proteins during early mitosis, increasing kinetochore–microtubule (MT) turnover and preventing premature stabilization of kinetochore–MT attachments. Phosphorylation of kinetochore proteins during late mitosis is low, promoting attachment stabilization, which is required for anaphase onset. The kinetochore protein KNL1 recruits Aurora B–counteracting phosphatases and the Aurora B–targeting factor Bub1, yet the consequences of KNL1 depletion on Aurora B phospho-regulation remain unknown. Here, we demonstrate that the KNL1 N terminus is essential for Aurora B activity at kinetochores. This region of KNL1 is also required for Bub1 kinase activity at kinetochores, suggesting that KNL1 promotes Aurora B activity through Bub1-mediated Aurora B targeting. However, ectopic targeting of Aurora B to kinetochores does not fully rescue Aurora B activity in KNL1-depleted cells, suggesting KNL1 influences Aurora B activity through an additional pathway. Our findings establish KNL1 as a requirement for Aurora B activity at kinetochores and for wild-type kinetochore–MT attachment dynamics.

scholarly journals Aurora B kinase is recruited to multiple discrete kinetochore and centromere regions in human cells

2020 ◽  
Vol 219 (3) ◽  
Author(s):  
Amanda J. Broad ◽  
Keith F. DeLuca ◽  
Jennifer G. DeLuca
Keyword(s):  
Kinase Activity ◽  
Critical Role ◽  
Aurora B ◽  
Histone H2a ◽  
Aurora B Kinase ◽  
Spindle Microtubules ◽  
Kinetochore Region ◽  
20 Nm ◽  
Discrete Populations ◽  
Early Mitosis

Aurora B kinase has a critical role in regulating attachments between kinetochores and spindle microtubules during mitosis. Early in mitosis, kinase activity at kinetochores is high to promote attachment turnover, and in later mitosis, activity decreases to ensure attachment stabilization. Aurora B localizes prominently to inner centromeres, and a population of the kinase is also detected at kinetochores. How Aurora B is recruited to and evicted from these regions to regulate kinetochore-microtubule attachments remains unclear. Here, we identified and investigated discrete populations of Aurora B at the centromere/kinetochore region. An inner centromere pool is recruited by Haspin phosphorylation of histone H3, and a kinetochore-proximal outer centromere pool is recruited by Bub1 phosphorylation of histone H2A. Finally, a third pool resides ~20 nm outside of the inner kinetochore protein CENP-C in early mitosis and does not require either the Bub1/pH2A/Sgo1 or Haspin/pH3 pathway for localization or activity. Our results suggest that distinct molecular pathways are responsible for Aurora B recruitment to centromeres and kinetochores.

scholarly journals Aurora B couples chromosome alignment with anaphase by targeting BubR1, Mad2, and Cenp-E to kinetochores

2003 ◽  
Vol 161 (2) ◽  
pp. 267-280 ◽  
Author(s):  
Claire Ditchfield ◽  
Victoria L. Johnson ◽  
Anthony Tighe ◽  
Rebecca Ellston ◽  
Carolyn Haworth ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Kinase Inhibitor ◽  
Spindle Checkpoint ◽  
Aurora Kinase ◽  
Multiple Roles ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Checkpoint Proteins ◽  
Anaphase Onset ◽  
Chromosome Alignment

The Aurora/Ipl1 family of protein kinases plays multiple roles in mitosis and cytokinesis. Here, we describe ZM447439, a novel selective Aurora kinase inhibitor. Cells treated with ZM447439 progress through interphase, enter mitosis normally, and assemble bipolar spindles. However, chromosome alignment, segregation, and cytokinesis all fail. Despite the presence of maloriented chromosomes, ZM447439-treated cells exit mitosis with normal kinetics, indicating that the spindle checkpoint is compromised. Indeed, ZM447439 prevents mitotic arrest after exposure to paclitaxel. RNA interference experiments suggest that these phenotypes are due to inhibition of Aurora B, not Aurora A or some other kinase. In the absence of Aurora B function, kinetochore localization of the spindle checkpoint components BubR1, Mad2, and Cenp-E is diminished. Furthermore, inhibition of Aurora B kinase activity prevents the rebinding of BubR1 to metaphase kinetochores after a reduction in centromeric tension. Aurora B kinase activity is also required for phosphorylation of BubR1 on entry into mitosis. Finally, we show that BubR1 is not only required for spindle checkpoint function, but is also required for chromosome alignment. Together, these results suggest that by targeting checkpoint proteins to kinetochores, Aurora B couples chromosome alignment with anaphase onset.

scholarly journals The Ki-67 and RepoMan mitotic phosphatases assemble via an identical, yet novel mechanism

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Ganesan Senthil Kumar ◽  
Ezgi Gokhan ◽  
Sofie De Munter ◽  
Mathieu Bollen ◽  
Paola Vagnarelli ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Mitotic Chromosome ◽  
Cancer Therapeutics ◽  
Mitotic Exit ◽  
Protein Phosphatase 1 ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Ki 67 ◽  
Anaphase Onset

Ki-67 and RepoMan have key roles during mitotic exit. Previously, we showed that Ki-67 organizes the mitotic chromosome periphery and recruits protein phosphatase 1 (PP1) to chromatin at anaphase onset, in a similar manner as RepoMan (<xref ref-type="bibr" rid="bib2">Booth et al., 2014</xref>). Here we show how Ki-67 and RepoMan form mitotic exit phosphatases by recruiting PP1, how they distinguish between distinct PP1 isoforms and how the assembly of these two holoenzymes are dynamically regulated by Aurora B kinase during mitosis. Unexpectedly, our data also reveal that Ki-67 and RepoMan bind PP1 using an identical, yet novel mechanism, interacting with a PP1 pocket that is engaged only by these two PP1 regulators. These findings not only show how two distinct mitotic exit phosphatases are recruited to their substrates, but also provide immediate opportunities for the design of novel cancer therapeutics that selectively target the Ki-67:PP1 and RepoMan:PP1 holoenzymes.

scholarly journals Aurora B kinase activity is regulated by SET/TAF1 on Sgo2 at the inner centromere

2019 ◽  
Vol 218 (10) ◽  
pp. 3223-3236 ◽  
Author(s):  
Yuichiro Asai ◽  
Koh Fukuchi ◽  
Yuji Tanno ◽  
Saki Koitabashi-Kiyozuka ◽  
Tatsuyuki Kiyozuka ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Chromosomal Instability ◽  
Kinase Activity ◽  
Fine Tuning ◽  
Aurora B ◽  
The Novel ◽  
Aurora B Kinase ◽  
Microtubule Attachment ◽  
Molecular Events

The accurate regulation of phosphorylation at the kinetochore is essential for establishing chromosome bi-orientation. Phosphorylation of kinetochore proteins by the Aurora B kinase destabilizes improper kinetochore–microtubule attachments, whereas the phosphatase PP2A has a counteracting role. Imbalanced phosphoregulation leads to error-prone chromosome segregation and aneuploidy, a hallmark of cancer cells. However, little is known about the molecular events that control the balance of phosphorylation at the kinetochore. Here, we show that localization of SET/TAF1, an oncogene product, to centromeres maintains Aurora B kinase activity by inhibiting PP2A, thereby correcting erroneous kinetochore–microtubule attachment. SET localizes at the inner centromere by interacting directly with shugoshin 2, with SET levels declining at increased distances between kinetochore pairs, leading to establishment of chromosome bi-orientation. Moreover, SET overexpression induces chromosomal instability by disrupting kinetochore–microtubule attachment. Thus, our findings reveal the novel role of SET in fine-tuning the phosphorylation level at the kinetochore by balancing the activities of Aurora B and PP2A.

scholarly journals VX-680 Inhibits Aurora A and Aurora B Kinase Activity in Human Cells

Cell Cycle ◽  
2007 ◽  
Vol 6 (22) ◽  
pp. 2846-2854 ◽  
Author(s):  
Rebecca K. Tyler ◽  
Natalia Shpiro ◽  
Rodolfo Marquez ◽  
Patrick A. Eyers
Keyword(s):  
Kinase Activity ◽  
Human Cells ◽  
Aurora B ◽  
Aurora A ◽  
Aurora B Kinase

The dietary flavonoid luteolin inhibits Aurora B kinase activity and blocks proliferation of cancer cells

2012 ◽  
Vol 46 (5) ◽  
pp. 388-396 ◽  
Author(s):  
Fang Xie ◽  
Qingyu Lang ◽  
Mei Zhou ◽  
Haoxing Zhang ◽  
Zhishun Zhang ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Kinase Activity ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Dietary Flavonoid

scholarly journals Use of DT40 conditional-knockout cell lines to study chromosomal passenger protein function

2010 ◽  
Vol 38 (6) ◽  
pp. 1655-1659 ◽  
Author(s):  
Xavier Fant ◽  
Kumiko Samejima ◽  
Ana Carvalho ◽  
Hiromi Ogawa ◽  
Zhenjie Xu ◽  
...  
Keyword(s):  
Cell Lines ◽  
Protein Function ◽  
Kinase Activity ◽  
Current Knowledge ◽  
Conditional Knockout ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Chromosomal Passenger ◽  
Passenger Protein

The CPC [chromosomal passenger complex; INCENP (inner centromere protein), Aurora B kinase, survivin and borealin] is implicated in many mitotic processes. In the present paper we describe how we generated DT40 conditional-knockout cell lines for incenp1 and survivin1 to better understand the role of these CPC subunits in the control of Aurora B kinase activity. These lines enabled us to reassess current knowledge of survivin function and to show that INCENP acts as a rheostat for Aurora B activity.

scholarly journals Bub1 overexpression induces aneuploidy and tumor formation through Aurora B kinase hyperactivation

2011 ◽  
Vol 193 (6) ◽  
pp. 1049-1064 ◽  
Author(s):  
Robin M. Ricke ◽  
Karthik B. Jeganathan ◽  
Jan M. van Deursen
Keyword(s):  
Protein Kinase ◽  
Transgenic Mice ◽  
Chromosome Segregation ◽  
Kinase Activity ◽  
Tumor Formation ◽  
High Expression ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Clinical Prognosis ◽  
Poor Clinical Prognosis

High expression of the protein kinase Bub1 has been observed in a variety of human tumors and often correlates with poor clinical prognosis, but its molecular and cellular consequences and role in tumorigenesis are unknown. Here, we demonstrate that overexpression of Bub1 in mice leads to near-diploid aneuploidies and tumor formation. We found that chromosome misalignment and lagging are the primary mitotic errors responsible for the observed aneuploidization. High Bub1 levels resulted in aberrant Bub1 kinase activity and hyperactivation of Aurora B kinase. When Aurora B activity is suppressed, pharmacologically or via BubR1 overexpression, chromosome segregation errors caused by Bub1 overexpression are largely corrected. Importantly, Bub1 transgenic mice overexpressing Bub1 developed various kinds of spontaneous tumors and showed accelerated Myc-induced lymphomagenesis. Our results establish that Bub1 has oncogenic properties and suggest that Aurora B is a critical target through which overexpressed Bub1 drives aneuploidization and tumorigenesis.

Sign in / Sign up

Export Citation Format

Share Document