Dynamic cell cycle-dependent phosphorylation modulates CENP-L-CENP-N centromere recruitment

Mapping Intimacies ◽

10.1101/2021.12.17.473210 ◽

2021 ◽

Author(s):

Alexandra P Navarro ◽

Iain M Cheeseman

Keyword(s):

Cell Cycle ◽

Chromosome Segregation ◽

S Phase ◽

Dependent Manner ◽

Dynamic Cell ◽

A Cell ◽

Cycle Dependent ◽

Unique Cell ◽

Localization Behavior ◽

Constitutive Phosphorylation

The kinetochore is a macromolecular structure that is required to ensure proper chromosome segregation during each cell division. The kinetochore is assembled upon a platform of the 16-subunit Constitutive Centromere Associated Network (CCAN), which is present at centromeres throughout the cell cycle. The nature and regulation of CCAN assembly, interactions, and dynamics required to facilitate changing centromere properties and requirements remain to be fully elucidated. The CENP-LN CCAN sub-complex displays a unique cell cycle-dependent localization behavior, peaking in S phase. Here, we demonstrate that phosphorylation of CENP-L and CENP-N controls CENP-LN complex formation and localization in a cell cycle-dependent manner. Mimicking constitutive phosphorylation of either CENP-L or CENP-N or simultaneously preventing phosphorylation of both proteins prevents CENP-LN localization and disrupts chromosome segregation. Together, our work suggests that cycles of phosphorylation and dephosphorylation are critical for CENP-LN complex recruitment and dynamics at centromeres to enable cell cycle-dependent CCAN reorganization.

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EGT2 gene transcription is induced predominantly by Swi5 in early G1.

Molecular and Cellular Biology ◽

10.1128/mcb.16.7.3264 ◽

1996 ◽

Vol 16 (7) ◽

pp. 3264-3274 ◽

Cited By ~ 61

Author(s):

B Kovacech ◽

K Nasmyth ◽

T Schuster

Keyword(s):

Cell Cycle ◽

Transcriptional Activation ◽

Cell Separation ◽

S Phase ◽

Dependent Manner ◽

Yeast Saccharomyces Cerevisiae ◽

Concentration Dependent Manner ◽

A Cell ◽

Cycle Dependent ◽

Ho Gene

In a screen for cell cycle-regulated genes in the yeast Saccharomyces cerevisiae, we have identified a gene, EGT2, which is involved in cell separation in the G1 stage of the cell cycle. Transcription of EGT2 is tightly regulated in a cell cycle-dependent manner. Transcriptional levels peak at the boundary of mitosis and early G1 The transcription factors responsible for EGT2 expression in early G1 are Swi5 and, to a lesser extent, Ace2. Swi5 is involved in the transcriptional activation of the HO gene during late G1 and early S phase, and Ace2 induces CTS1 transcription during early and late G1 We show that Swi5 activates EGT2 transcription as soon as it enters the nucleus at the end of mitosis in a concentration-dependent manner. Since Swi5 is unstable in the nucleus, its level drops rapidly, causing termination of EGT2 transcription before cells are committed to the next cell cycle. However, Swi5 is still able to activate transcription of HO in late G1 in conjunction with additional activators such as Swi4 and Swi6.

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Topoisomerase IIα Prevents, But Does Not Resolve, Ultrafine Anaphase Bridges By Two Mechanisms

10.1101/815001 ◽

2019 ◽

Author(s):

Simon Gemble ◽

Géraldine Buhagiar-Labarchède ◽

Rosine Onclercq-Delic ◽

Sarah Lambert ◽

Mounira Amor-Guéret

Keyword(s):

Cell Cycle ◽

Dna Replication ◽

S Phase ◽

Cycle Phase ◽

Dependent Manner ◽

Topoisomerase Iiα ◽

Anaphase Bridges ◽

Double Stranded Dna ◽

A Cell ◽

Cycle Dependent

AbstractTopoisomerase IIα (Topo IIα), a well-conserved double-stranded DNA (dsDNA)-specific decatenase, processes dsDNA catenanes resulting from DNA replication during mitosis. Topo IIα defects lead to an accumulation of ultrafine anaphase bridges (UFBs), a type of chromosome non-disjunction. Topo IIα has been reported to resolve DNA anaphase threads, possibly accounting for the increase in UFB frequency upon Topo IIα inhibition. We hypothesized that the excess UFBs might also result, at least in part, from an impairment of the prevention of UFB formation by Topo IIα. We found that Topo IIα inhibition promotes UFB formation without affecting UFB resolution during anaphase. Moreover, we showed that Topo IIα inhibition promotes the formation of two types of UFBs depending on cell-cycle phase. Topo IIα inhibition during S-phase compromises complete DNA replication, leading to the formation of UFB-containing unreplicated DNA, whereas Topo IIα inhibition during mitosis impedes DNA decatenation at metaphase-anaphase transition, leading to the formation of UFB-containing DNA catenanes. Thus, Topo IIα activity is essential to prevent UFB formation in a cell-cycle dependent manner, but dispensable for UFB resolution during anaphase.

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Distinct Developmental Function of Two Caenorhabditis elegans Homologs of the Cohesin Subunit Scc1/Rad21

Molecular Biology of the Cell ◽

10.1091/mbc.e02-09-0603 ◽

2003 ◽

Vol 14 (6) ◽

pp. 2399-2409 ◽

Cited By ~ 21

Author(s):

Yoshiko Mito ◽

Asako Sugimoto ◽

Masayuki Yamamoto

Keyword(s):

Cell Cycle ◽

Caenorhabditis Elegans ◽

Chromosome Segregation ◽

Mitotic Chromosome ◽

Dependent Manner ◽

C Elegans ◽

Late Embryogenesis ◽

A Cell ◽

Cohesin Subunit ◽

Cycle Dependent

Cohesin, which mediates sister chromatid cohesion, is composed of four subunits, named Scc1/Rad21, Scc3, Smc1, and Smc3 in yeast. Caenorhabditis elegans has a single homolog for each of Scc3, Smc1, and Smc3, but as many as four for Scc1/Rad21 (COH-1, SCC-1/COH-2, COH-3, and REC-8). Except for REC-8 required for meiosis, function of these C. elegans proteins remains largely unknown. Herein, we examined their possible involvement in mitosis and development. Embryos depleted of the homolog of either Scc3, or Smc1, or Smc3 by RNA interference revealed a defect in mitotic chromosome segregation but not in chromosome condensation and cytokinesis. Depletion of SCC-1/COH-2 caused similar phenotypes. SCC-1/COH-2 was present in cells destined to divide. It localized to chromosomes in a cell cycle-dependent manner. Worms depleted of COH-1 arrested at either the late embryonic or the larval stage, with no indication of mitotic dysfunction. COH-1 associated chromosomes throughout the cell cycle in all somatic cells undergoing late embryogenesis or larval development. Thus, SCC-1/COH-2 and the homologs of Scc3, Smc1, and Smc3 facilitate mitotic chromosome segregation during the development, presumably by forming a cohesin complex, whereas COH-1 seems to play a role important for development but unrelated to mitosis.

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Cell cycle-associated accumulation of tissue inhibitor of metalloproteinases-1 (TIMP-1) in the nuclei of human gingival fibroblasts

Journal of Cell Science ◽

10.1242/jcs.111.9.1147 ◽

1998 ◽

Vol 111 (9) ◽

pp. 1147-1153

Author(s):

W.Q. Zhao ◽

H. Li ◽

K. Yamashita ◽

X.K. Guo ◽

T. Hoshino ◽

...

Keyword(s):

Cell Cycle ◽

Calf Serum ◽

Nuclear Extract ◽

S Phase ◽

Human Gingival Fibroblasts ◽

Dependent Manner ◽

Gingival Fibroblasts ◽

A Cell ◽

Cycle Dependent ◽

Sandwich Enzyme Immunoassay

We first confirmed an earlier immunohistochemical study showing that immunoreactive TIMP-1-like protein accumulated in the nuclei of human gingival fibroblasts (Gin-1 cells), reaching a maximum in the S phase of the cell cycle (Li, H., Nishio, K., Yamashita, K., Hayakawa, T. and Hoshino, T. (1995). Nagoya J. Med. Sci. 58, 133–142). Then we isolated this protein from a nuclear extract of Gin-1 cells and demonstrated it to be identical to human recombinant TIMP-1 by western blotting, by a sandwich enzyme immunoassay for TIMP-1 and by an assay for matrix metalloproteinase inhibition. The amount of TIMP-1 in the cytosolic fraction of quiescent Gin-1 cells after stimulation by fetal calf serum increased continuously for 48 hours, whereas that in the nuclear extract showed a maximum at 24 hours (S phase) and significantly decreased thereafter. Gin-1 cells expressed mRNAs for both TIMP-2 and TIMP-3 together with mRNA for TIMP-1. However, neither TIMP-2 nor TIMP-3 proteins seemed to accumulate in the nuclei of Gin-1 cells. These facts strongly suggest that TIMP-1 accumulates specifically in the nuclei of Gin-1 cells in a cell cycle-dependent manner.

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Truncated APC regulates the transcriptional activity of β-catenin in a cell cycle dependent manner

Human Molecular Genetics ◽

10.1093/hmg/ddl464 ◽

2006 ◽

Vol 16 (2) ◽

pp. 199-209 ◽

Cited By ~ 38

Author(s):

Jean Schneikert ◽

Annette Grohmann ◽

Jürgen Behrens

Keyword(s):

Cell Cycle ◽

Transcriptional Activity ◽

Dependent Manner ◽

A Cell ◽

Cycle Dependent

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The mammalian Cut homeodomain protein functions as a cell-cycle-dependent transcriptional repressor which downmodulates p21WAF1/CIP1/SDI1 in S phase

The EMBO Journal ◽

10.1093/emboj/17.16.4680 ◽

1998 ◽

Vol 17 (16) ◽

pp. 4680-4694 ◽

Cited By ~ 103

Author(s):

O. Coqueret

Keyword(s):

Cell Cycle ◽

Transcriptional Repressor ◽

S Phase ◽

Homeodomain Protein ◽

Protein Functions ◽

A Cell ◽

Cycle Dependent

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Ser68 phosphoregulation is essential for CENP-A deposition, centromere function and viability in mice

10.1101/2021.11.23.469796 ◽

2021 ◽

Author(s):

Yuting Liu ◽

Kehui Wang ◽

Li Huang ◽

Jicheng Zhao ◽

Xinpeng Chen ◽

...

Keyword(s):

Cell Cycle ◽

Cell Viability ◽

Histone H3 ◽

Dependent Manner ◽

Centromere Function ◽

Histone H3 Variant ◽

A Cell ◽

Cycle Dependent ◽

Spatiotemporal Control

Centromere identity is defined by nucleosomes containing CENP-A, a histone H3 variant. The deposition of CENP-A at centromeres is tightly regulated in a cell-cycle-dependent manner. We previously reported that the spatiotemporal control of centromeric CENP-A incorporation is mediated by the phosphorylation of CENP-A Ser68. However, a recent report argued that Ser68 phosphoregulation is dispensable for accurate CENP-A loading. Here, we report that the substitution of Ser68 of endogenous CENP-A with either Gln68 or Glu68 severely impairs CENP-A deposition and cell viability. We also find that mice harboring the corresponding mutations are lethal. Together, these results indicate that the dynamic phosphorylation of Ser68 ensures cell-cycle-dependent CENP-A deposition and cell viability.

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Gcn5-mediated acetylation at MBF-regulated promoters induces the G1/S transcriptional wave

Nucleic Acids Research ◽

10.1093/nar/gkz561 ◽

2019 ◽

Vol 47 (16) ◽

pp. 8439-8451 ◽

Cited By ~ 1

Author(s):

Alberto González-Medina ◽

Elena Hidalgo ◽

José Ayté

Keyword(s):

Cell Cycle ◽

Molecular Mechanisms ◽

Histone H3 ◽

Dependent Manner ◽

Saga Complex ◽

Lysine Residues ◽

Physical Barriers ◽

A Cell ◽

Cycle Dependent ◽

Regulated Promoters

Abstract In fission yeast, MBF-dependent transcription is inactivated at the end of S phase through a negative feedback loop that involves the co-repressors, Yox1 and Nrm1. Although this repression system is well known, the molecular mechanisms involved in MBF activation remain largely unknown. Compacted chromatin constitutes a barrier to activators accessing promoters. Here, we show that chromatin regulation plays a key role in activating MBF-dependent transcription. Gcn5, a part of the SAGA complex, binds to MBF-regulated promoters through the MBF co-activator Rep2 in a cell cycle-dependent manner and in a reverse correlation to the binding of the MBF co-repressors, Nrm1 or Yox1. We propose that the co-repressors function as physical barriers to SAGA recruitment onto MBF promoters. We also show that Gcn5 acetylates specific lysine residues on histone H3 in a cell cycle-regulated manner. Furthermore, either in a gcn5 mutant or in a strain in which histone H3 is kept in an unacetylated form, MBF-dependent transcription is downregulated. In summary, Gcn5 is required for the full activation and correct timing of MBF-regulated gene transcription.

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