scholarly journals Spatiotemporal coordination of the RSF1-PLK1-Aurora B cascade establishes mitotic signaling platforms

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ho-Soo Lee ◽  
Sunwoo Min ◽  
Ye-Eun Jung ◽  
Sunyoung Chae ◽  
June Heo ◽  
...  

AbstractThe chromatin remodeler RSF1 enriched at mitotic centromeres is essential for proper chromosome alignment and segregation and underlying mechanisms remain to be disclosed. We here show that PLK1 recruitment by RSF1 at centromeres creates an activating phosphorylation on Thr236 in the activation loop of Aurora B and this is indispensable for the Aurora B activation. In structural modeling the phosphorylated Thr236 enhances the base catalysis by Asp200 nearby, facilitating the Thr232 autophosphorylation. Accordingly, RSF1-PLK1 is central for Aurora B-mediated microtubule destabilization in error correction. However, under full microtubule-kinetochore attachment RSF1-PLK1 positions at kinetochores, halts activating Aurora B and phosphorylates BubR1, regardless of tension. Spatial movement of RSF1-PLK1 to kinetochores is triggered by Aurora B-mediated phosphorylation of centromeric histone H3 on Ser28. We propose a regulatory RSF1-PLK1 axis that spatiotemporally controls on/off switch on Aurora B. This feedback circuit among RSF1-PLK1-Aurora B may coordinate dynamic microtubule-kinetochore attachment in early mitosis when full tension yet to be generated.

2012 ◽  
Vol 199 (2) ◽  
pp. 251-268 ◽  
Author(s):  
Fangwei Wang ◽  
Natalia P. Ulyanova ◽  
John R. Daum ◽  
Debasis Patnaik ◽  
Anna V. Kateneva ◽  
...  

Haspin phosphorylates histone H3 at threonine-3 (H3T3ph), providing a docking site for the Aurora B complex at centromeres. Aurora B functions to correct improper kinetochore–microtubule attachments and alert the spindle checkpoint to the presence of misaligned chromosomes. We show that Haspin inhibitors decreased H3T3ph, resulting in loss of centromeric Aurora B and reduced phosphorylation of centromere and kinetochore Aurora B substrates. Consequently, metaphase chromosome alignment and spindle checkpoint signaling were compromised. These effects were phenocopied by microinjection of anti-H3T3ph antibodies. Retargeting Aurora B to centromeres partially restored checkpoint signaling and Aurora B–dependent phosphorylation at centromeres and kinetochores, bypassing the need for Haspin activity. Haspin inhibitors did not obviously affect phosphorylation of histone H3 at serine-10 (H3S10ph) by Aurora B on chromosome arms but, in Aurora B reactivation assays, recovery of H3S10ph was delayed. Haspin inhibitors did not block Aurora B localization to the spindle midzone in anaphase or Aurora B function in cytokinesis. Thus, Haspin inhibitors reveal centromeric roles of Aurora B in chromosome movement and spindle checkpoint signaling.


2001 ◽  
Vol 153 (4) ◽  
pp. 865-880 ◽  
Author(s):  
Richard R. Adams ◽  
Helder Maiato ◽  
William C. Earnshaw ◽  
Mar Carmena

We have performed a biochemical and double-stranded RNA-mediated interference (RNAi) analysis of the role of two chromosomal passenger proteins, inner centromere protein (INCENP) and aurora B kinase, in cultured cells of Drosophila melanogaster. INCENP and aurora B function is tightly interlinked. The two proteins bind to each other in vitro, and DmINCENP is required for DmAurora B to localize properly in mitosis and function as a histone H3 kinase. DmAurora B is required for DmINCENP accumulation at centromeres and transfer to the spindle at anaphase. RNAi for either protein dramatically inhibited the ability of cells to achieve a normal metaphase chromosome alignment. Cells were not blocked in mitosis, however, and entered an aberrant anaphase characterized by defects in sister kinetochore disjunction and the presence of large amounts of amorphous lagging chromatin. Anaphase A chromosome movement appeared to be normal, however cytokinesis often failed. DmINCENP and DmAurora B are not required for the correct localization of the kinesin-like protein Pavarotti (ZEN-4/CHO1/MKLP1) to the midbody at telophase. These experiments reveal that INCENP is required for aurora B kinase function and confirm that the chromosomal passengers have essential roles in mitosis.


2019 ◽  
Vol 219 (2) ◽  
Author(s):  
Cai Liang ◽  
Zhenlei Zhang ◽  
Qinfu Chen ◽  
Haiyan Yan ◽  
Miao Zhang ◽  
...  

Aurora B kinase plays an essential role in chromosome bi-orientation, which is a prerequisite for equal segregation of chromosomes during mitosis. However, it remains largely unclear whether centromere-localized Aurora B is required for faithful chromosome segregation. Here we show that histone H3 Thr-3 phosphorylation (H3pT3) and H2A Thr-120 phosphorylation (H2ApT120) can independently recruit Aurora B. Disrupting H3pT3-mediated localization of Aurora B at the inner centromere impedes the decline in H2ApT120 during metaphase and causes H2ApT120-dependent accumulation of Aurora B at the kinetochore-proximal centromere. Consequently, silencing of the spindle assembly checkpoint (SAC) is delayed, whereas the fidelity of chromosome segregation is negligibly affected. Further eliminating an H2ApT120-dependent pool of Aurora B restores proper timing for SAC silencing but increases chromosome missegregation. Our data indicate that H2ApT120-mediated localization of Aurora B compensates for the loss of an H3pT3-dependent pool of Aurora B to correct improper kinetochore–microtubule attachments. This study provides important insights into how centromeric Aurora B regulates SAC and kinetochore attachment to microtubules to ensure error-free chromosome segregation.


2011 ◽  
Vol 20 (3) ◽  
pp. 342-352 ◽  
Author(s):  
Lina Cheng ◽  
Jiayin Zhang ◽  
Sana Ahmad ◽  
Lorene Rozier ◽  
Haiqian Yu ◽  
...  

2011 ◽  
Vol 22 (9) ◽  
pp. 1473-1485 ◽  
Author(s):  
Zuzana Storchová ◽  
Justin S. Becker ◽  
Nicolas Talarek ◽  
Sandra Kögelsberger ◽  
David Pellman

The conserved mitotic kinase Bub1 performs multiple functions that are only partially characterized. Besides its role in the spindle assembly checkpoint and chromosome alignment, Bub1 is crucial for the kinetochore recruitment of multiple proteins, among them Sgo1. Both Bub1 and Sgo1 are dispensable for growth of haploid and diploid budding yeast, but they become essential in cells with higher ploidy. We find that overexpression of SGO1 partially corrects the chromosome segregation defect of bub1Δ haploid cells and restores viability to bub1Δ tetraploid cells. Using an unbiased high-copy suppressor screen, we identified two members of the chromosomal passenger complex (CPC), BIR1 (survivin) and SLI15 (INCENP, inner centromere protein), as suppressors of the growth defect of both bub1Δ and sgo1Δ tetraploids, suggesting that these mutants die due to defects in chromosome biorientation. Overexpression of BIR1 or SLI15 also complements the benomyl sensitivity of haploid bub1Δ and sgo1Δ cells. Mutants lacking SGO1 fail to biorient sister chromatids attached to the same spindle pole (syntelic attachment) after nocodazole treatment. Moreover, the sgo1Δ cells accumulate syntelic attachments in unperturbed mitoses, a defect that is partially corrected by BIR1 or SLI15 overexpression. We show that in budding yeast neither Bub1 nor Sgo1 is required for CPC localization or affects Aurora B activity. Instead we identify Sgo1 as a possible partner of Mps1, a mitotic kinase suggested to have an Aurora B–independent function in establishment of biorientation. We found that Sgo1 overexpression rescues defects caused by metaphase inactivation of Mps1 and that Mps1 is required for Sgo1 localization to the kinetochore. We propose that Bub1, Sgo1, and Mps1 facilitate chromosome biorientation independently of the Aurora B–mediated pathway at the budding yeast kinetochore and that both pathways are required for the efficient turnover of syntelic attachments.


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