scholarly journals CENP-A is phosphorylated by Aurora B kinase and plays an unexpected role in completion of cytokinesis

2001 ◽  
Vol 155 (7) ◽  
pp. 1147-1158 ◽  
Author(s):  
Samantha G. Zeitlin ◽  
Richard D. Shelby ◽  
Kevin F. Sullivan
Keyword(s):  
Protein A ◽  
Phosphorylation Site ◽  
Histone H3 ◽  
Dominant Negative ◽  
Aurora B ◽  
Human Centromere ◽  
Centromere Protein ◽  
Centromere Protein A ◽  
Chromosomal Passenger

Aurora B is a mitotic protein kinase that phosphorylates histone H3, behaves as a chromosomal passenger protein, and functions in cytokinesis. We investigated a role for Aurora B with respect to human centromere protein A (CENP-A), a centromeric histone H3 homologue. Aurora B concentrates at centromeres in early G2, associates with histone H3 and centromeres at the times when histone H3 and CENP-A are phosphorylated, and phosphorylates histone H3 and CENP-A in vitro at a similar target serine residue. Dominant negative phosphorylation site mutants of CENP-A result in a delay at the terminal stage of cytokinesis (cell separation). The only molecular defects detected in analysis of 22 chromosomal, spindle, and regulatory proteins were disruptions in localization of inner centromere protein (INCENP), Aurora B, and a putative partner phosphatase, PP1γ1. Our data support a model where CENP-A phosphorylation is involved in regulating Aurora B, INCENP, and PP1γ1 targeting within the cell. These experiments identify an unexpected role for the kinetochore in regulation of cytokinesis.

scholarly journals Human centromere protein A (CENP-A) can replace histone H3 in nucleosome reconstitution in vitro

2000 ◽  
Vol 97 (13) ◽  
pp. 7266-7271 ◽  
Author(s):  
K. Yoda ◽  
S. Ando ◽  
S. Morishita ◽  
K. Houmura ◽  
K. Hashimoto ◽  
...  
Keyword(s):  
Protein A ◽  
Histone H3 ◽  
Human Centromere ◽  
Centromere Protein ◽  
Centromere Protein A

Differential regulation of CENP-A and histone H3 phosphorylation in G2/M

2001 ◽  
Vol 114 (4) ◽  
pp. 653-661 ◽  
Author(s):  
S.G. Zeitlin ◽  
C.M. Barber ◽  
C.D. Allis ◽  
K. Sullivan
Keyword(s):  
Protein A ◽  
Phosphorylation Site ◽  
Histone H3 ◽  
Condensation Process ◽  
Sequence Motif ◽  
H3 Phosphorylation ◽  
Centromere Protein A ◽  
Putative Phosphorylation Site ◽  
Mitotic Phosphorylation ◽  
Histone H3 Phosphorylation

After DNA replication, cells condense their chromosomes in order to segregate them during mitosis. The condensation process as well as subsequent segregation requires phosphorylation of histone H3 at serine 10. Histone H3 phosphorylation initiates during G2 in pericentric foci prior to H3 phosphorylation in the chromosome arms. Centromere protein A (CENP-A), a histone H3-like protein found uniquely at centromeres, contains a sequence motif similar to that around H3 Ser10, suggesting that CENP-A phosphorylation might be linked to pericentric initiation of histone H3 phosphorylation. To test this hypothesis, we generated peptide antibodies against the putative phosphorylation site of CENP-A. ELISA, western blot and immunocytochemical analyses show that CENP-A is phosphorylated at the shared motif. Simultaneous co-detection demonstrates that phosphorylation of CENP-A and histone H3 are separate events in G2/M. CENP-A phosphorylation occurs after both pericentric initiation and genome-wide stages of histone H3 phosphorylation. Quantitative immunocytochemistry reveals that CENP-A phosphorylation begins in prophase and reaches maximal levels in prometaphase. CENP-A phosphoepitope reactivity is lost during anaphase and becomes undetectable in telophase cells. Duplication of prekinetochores, detected as the doubling of CENP-A foci, occurs prior to complete histone H3 phosphorylation in G2. Mitotic phosphorylation of histone H3-family proteins shows tight spatial and temporal control, occurring in three phases: (1) pericentric H3 phosphorylation, (2) chromosome arm H3 phosphorylation and (3) CENP-A phosphorylation at kinetochores. These observations reveal new cytological landmarks characteristic of G2 progression.

scholarly journals Constitutive centromere-associated network contacts confer differential stability on CENP-A nucleosomes in vitro and in the cell

2018 ◽  
Vol 29 (6) ◽  
pp. 751-762 ◽  
Author(s):  
Shengya Cao ◽  
Keda Zhou ◽  
Zhening Zhang ◽  
Karolin Luger ◽  
Aaron F. Straight
Keyword(s):  
Protein A ◽  
Histone H3 ◽  
Intrinsic Property ◽  
Cell Cycles ◽  
Centromere Protein A ◽  
Histone H3 Variant ◽  
Differential Stability ◽  
The Stability

Eukaryotic centromeres are defined by the presence of nucleosomes containing the histone H3 variant, centromere protein A (CENP-A). Once incorporated at centromeres, CENP-A nucleosomes are remarkably stable, exhibiting no detectable loss or exchange over many cell cycles. It is currently unclear whether this stability is an intrinsic property of CENP-A containing chromatin or whether it arises from proteins that specifically associate with CENP-A chromatin. Two proteins, CENP-C and CENP-N, are known to bind CENP-A human nucleosomes directly. Here we test the hypothesis that CENP-C or CENP-N stabilize CENP-A nucleosomes in vitro and in living cells. We show that CENP-N stabilizes CENP-A nucleosomes alone and additively with CENP-C in vitro. However, removal of CENP-C and CENP-N from cells, or mutating CENP-A so that it no longer interacts with CENP-C or CENP-N, had no effect on centromeric CENP-A stability in vivo. Thus, the stability of CENP-A nucleosomes in chromatin does not arise solely from its interactions with CENP-C or CENP-N.

scholarly journals Uracil DNA N-Glycosylase Promotes Assembly of Human Centromere Protein A

PLoS ONE ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. e17151 ◽  
Author(s):  
Samantha G. Zeitlin ◽  
Brian R. Chapados ◽  
Norman M. Baker ◽  
Caroline Tai ◽  
Geir Slupphaug ◽  
...  
Keyword(s):  
Protein A ◽  
Human Centromere ◽  
Centromere Protein ◽  
Centromere Protein A

scholarly journals Borealin

2004 ◽  
Vol 166 (2) ◽  
pp. 179-191 ◽  
Author(s):  
Reto Gassmann ◽  
Ana Carvalho ◽  
Alexander J. Henzing ◽  
Sandrine Ruchaud ◽  
Damien F. Hudson ◽  
...  
Keyword(s):  
Rna Interference ◽  
Histone H3 ◽  
Aurora B ◽  
Mitotic Progression ◽  
Aurora B Kinase ◽  
Chromosomal Passenger Complex ◽  
Central Spindle ◽  
Chromosomal Passenger ◽  
Bipolar Spindles

The chromosomal passenger complex of Aurora B kinase, INCENP, and Survivin has essential regulatory roles at centromeres and the central spindle in mitosis. Here, we describe Borealin, a novel member of the complex. Approximately half of Aurora B in mitotic cells is complexed with INCENP, Borealin, and Survivin; and Borealin binds Survivin and INCENP in vitro. A second complex contains Aurora B and INCENP, but no Borealin or Survivin. Depletion of Borealin by RNA interference delays mitotic progression and results in kinetochore–spindle misattachments and an increase in bipolar spindles associated with ectopic asters. The extra poles, which apparently form after chromosomes achieve a bipolar orientation, severely disrupt the partitioning of chromosomes in anaphase. Borealin depletion has little effect on histone H3 serine10 phosphorylation. These results implicate the chromosomal passenger holocomplex in the maintenance of spindle integrity and suggest that histone H3 serine10 phosphorylation is performed by an Aurora B–INCENP subcomplex.

scholarly journals Essential Roles of Drosophila Inner Centromere Protein (Incenp) and Aurora B in Histone H3 Phosphorylation, Metaphase Chromosome Alignment, Kinetochore Disjunction, and Chromosome Segregation

2001 ◽  
Vol 153 (4) ◽  
pp. 865-880 ◽  
Author(s):  
Richard R. Adams ◽  
Helder Maiato ◽  
William C. Earnshaw ◽  
Mar Carmena
Keyword(s):  
Metaphase Chromosome ◽  
Cultured Cells ◽  
Histone H3 ◽  
Aurora B ◽  
Aurora B Kinase ◽  
Centromere Protein ◽  
H3 Phosphorylation ◽  
Chromosome Alignment ◽  
Chromosomal Passenger Proteins

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.

scholarly journals Active establishment of centromeric CENP-A chromatin by RSF complex

2009 ◽  
Vol 185 (3) ◽  
pp. 397-407 ◽  
Author(s):  
Marinela Perpelescu ◽  
Naohito Nozaki ◽  
Chikashi Obuse ◽  
Hua Yang ◽  
Kinya Yoda
Keyword(s):  
Protein A ◽  
Centromeric Chromatin ◽  
Daughter Cells ◽  
Centromere Protein ◽  
Centromere Protein A ◽  
Protein Components ◽  
And Function ◽  
Relationship Of ◽  
The Relationship

Centromeres are chromosomal structures required for equal DNA segregation to daughter cells, comprising specialized nucleosomes containing centromere protein A (CENP-A) histone, which provide the basis for centromeric chromatin assembly. Discovery of centromere protein components is progressing, but knowledge related to their establishment and maintenance remains limited. Previously, using anti-CENP-A native chromatin immunoprecipitation, we isolated the interphase–centromere complex (ICEN). Among ICEN components, subunits of the remodeling and spacing factor (RSF) complex, Rsf-1 and SNF2h proteins, were found. This paper describes the relationship of the RSF complex to centromere structure and function, demonstrating its requirement for maintenance of CENP-A at the centromeric core chromatin in HeLa cells. The RSF complex interacted with CENP-A chromatin in mid-G1. Rsf-1 depletion induced loss of centromeric CENP-A, and purified RSF complex reconstituted and spaced CENP-A nucleosomes in vitro. From these data, we propose the RSF complex as a new factor actively supporting the assembly of CENP-A chromatin.

scholarly journals Restoration of Silencing in Saccharomyces cerevisiae by Tethering of a Novel Sir2-Interacting Protein, Esc8

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 633-645 ◽  
Author(s):  
Guido Cuperus ◽  
David Shore
Keyword(s):  
Protein A ◽  
Dominant Negative ◽  
Class I ◽  
Dominant Negative Effect ◽  
Rna Pol Ii ◽  
Interacting Protein ◽  
Nucleosome Remodeling ◽  
Negative Effect ◽  
Close Homolog

Abstract We previously described two classes of SIR2 mutations specifically defective in either telomeric/HM silencing (class I) or rDNA silencing (class II) in S. cerevisiae. Here we report the identification of genes whose protein products, when either overexpressed or directly tethered to the locus in question, can establish silencing in SIR2 class I mutants. Elevated dosage of SCS2, previously implicated as a regulator of both inositol biosynthesis and telomeric silencing, suppressed the dominant-negative effect of a SIR2-143 mutation. In a genetic screen for proteins that restore silencing when tethered to a telomere, we isolated ESC2 and an uncharacterized gene, (YOL017w), which we call ESC8. Both Esc2p and Esc8p interact with Sir2p in two-hybrid assays, and the Esc8p-Sir2 interaction is detected in vitro. Interestingly, Esc8p has a single close homolog in yeast, the ISW1-complex factor Ioc3p, and has also been copurified with Isw1p, raising the possibility that Esc8p is a component of an Isw1p-containing nucleosome remodeling complex. Whereas esc2 and esc8 deletion mutants alone have only marginal silencing defects, cells lacking Isw1p show a strong silencing defect at HMR but not at telomeres. Finally, we show that Esc8p interacts with the Gal11 protein, a component of the RNA pol II mediator complex.

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