Spindlin, a major maternal transcript expressed in the mouse during the transition from oocyte to embryo

Development ◽  
1997 ◽  
Vol 124 (2) ◽  
pp. 493-503 ◽  
Author(s):  
B. Oh ◽  
S.Y. Hwang ◽  
D. Solter ◽  
B.B. Knowles
Keyword(s):  
Cell Cycle ◽  
Mitotic Cell ◽  
Meiotic Spindle ◽  
Post Translational Modification ◽  
Gene Encoding ◽  
Cell Stage ◽  
Initial Development ◽  
Maternal Transcript ◽  
Stage Embryo ◽  
Cycle Dependent

Timely translation of maternal transcripts and post-translational modification of their gene products control the initial development of preimplantation-stage embryos. We have isolated and characterized a gene encoding a stage-specific embryonic protein. This novel gene, spindlin (Spin), is an abundant maternal transcript present in the unfertilized egg and 2-cell, but not 8-cell, stage embryo. Spin exhibits high homology to a multicopy gene, Y-linked spermiogenesis-specific transcript (Ssty), and together they form a new gene family expressed during gametogenesis. We find that spindlin associates with the meiotic spindle and is modified by phosphorylation in a cell-cycle-dependent fashion. Furthermore, it comigrates with the previously described 30x10(3) Mr metaphase complex which is posttranslationally modified during the first mitotic cell cycle. Our data suggest that spindlin plays a role in cell-cycle regulation during the transition from gamete to embryo.

scholarly journals An extensive program of periodic alternative splicing linked to cell cycle progression

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Daniel Dominguez ◽  
Yi-Hsuan Tsai ◽  
Robert Weatheritt ◽  
Yang Wang ◽  
Benjamin J Blencowe ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Alternative Splicing ◽  
Protein Interactions ◽  
Cell Cycle Progression ◽  
Cell Cycle Control ◽  
Mitotic Cell ◽  
Protein Protein Interactions ◽  
Post Translational Modification ◽  
Sr Protein ◽  
Cycle Dependent

Progression through the mitotic cell cycle requires periodic regulation of gene function at the levels of transcription, translation, protein-protein interactions, post-translational modification and degradation. However, the role of alternative splicing (AS) in the temporal control of cell cycle is not well understood. By sequencing the human transcriptome through two continuous cell cycles, we identify ~1300 genes with cell cycle-dependent AS changes. These genes are significantly enriched in functions linked to cell cycle control, yet they do not significantly overlap genes subject to periodic changes in steady-state transcript levels. Many of the periodically spliced genes are controlled by the SR protein kinase CLK1, whose level undergoes cell cycle-dependent fluctuations via an auto-inhibitory circuit. Disruption of CLK1 causes pleiotropic cell cycle defects and loss of proliferation, whereas CLK1 over-expression is associated with various cancers. These results thus reveal a large program of CLK1-regulated periodic AS intimately associated with cell cycle control.

scholarly journals Reducing inositol lipid hydrolysis, Ins(1,4,5)P3 receptor availability, or Ca2+ gradients lengthens the duration of the cell cycle in Xenopus laevis blastomeres.

1992 ◽  
Vol 116 (1) ◽  
pp. 147-156 ◽  
Author(s):  
J K Han ◽  
K Fukami ◽  
R Nuccitelli
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Xenopus Laevis ◽  
Mitotic Cell ◽  
Embryonic Cell ◽  
Cycle Duration ◽  
Cell Stage ◽  
Stage Embryo ◽  
Rate Of Hydrolysis ◽  
Xenopus Laevis Embryos

We have microinjected a mAb specifically directed to phosphatidylinositol 4,5-bisphosphate (PIP2) into one blastomere of two-cell stage Xenopus laevis embryos. This antibody binds to endogenous PIP2 and reduces its rate of hydrolysis by phospholipase C. Antibody-injected blastomeres undergo partial or complete arrest of the cell cycle whereas the uninjected sister blastomeres divided normally. Since PIP2 hydrolysis normally produces diacylglycerol (DG) and inositol 1,4,5-triphosphate (Ins[1,4,5]P3), we attempted to measure changes in the levels of DG following stimulation of PIP2 hydrolysis in antibody-injected oocytes. The total amount of DG in antibody-injected oocytes was significantly reduced compared to that of water-injected ones following stimulation by either acetylcholine or progesterone indicating that the antibody does indeed suppress PIP2 hydrolysis. We also found that the PIP2 antibodies greatly reduced the amount of intracellular Ca2+ released in the egg cortex during egg activation. As an indirect test for Ins(1,4,5)P3 involvement in the cell cycle we injected heparin which competes with Ins(1,4,5)P3 for binding to its receptor, and thus inhibits Ins(1,4,5)P3-induced Ca2+ release. Microinjection of heparin into one blastomere of the two-cell stage embryo caused partial or complete arrest of the cell cycle depending upon the concentration of heparin injected. We further investigated the effect of reducing any [Ca2+]i gradients by microinjecting dibromo-BAPTA into the blastomere. Dibromo-BAPTA injection completely blocked mitotic cell division when a final concentration of 1.5 mM was used. These results suggest that PIP2 turnover as well as second messenger activity influence cell cycle duration during embryonic cell division in frogs.

scholarly journals Coupling Phosphate Homeostasis to Cell Cycle-Specific Transcription: Mitotic Activation of Saccharomyces cerevisiae PHO5 by Mcm1 and Forkhead Proteins

2009 ◽  
Vol 29 (18) ◽  
pp. 4891-4905 ◽  
Author(s):  
Santhi Pondugula ◽  
Daniel W. Neef ◽  
Warren P. Voth ◽  
Russell P. Darst ◽  
Archana Dhasarathy ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Mitotic Cell ◽  
Dependent Manner ◽  
Phosphate Homeostasis ◽  
Periodic Cell ◽  
M Phase ◽  
Cycle Dependent ◽  
Nutrient Homeostasis

ABSTRACT Cells devote considerable resources to nutrient homeostasis, involving nutrient surveillance, acquisition, and storage at physiologically relevant concentrations. Many Saccharomyces cerevisiae transcripts coding for proteins with nutrient uptake functions exhibit peak periodic accumulation during M phase, indicating that an important aspect of nutrient homeostasis involves transcriptional regulation. Inorganic phosphate is a central macronutrient that we have previously shown oscillates inversely with mitotic activation of PHO5. The mechanism of this periodic cell cycle expression remains unknown. To date, only two sequence-specific activators, Pho4 and Pho2, were known to induce PHO5 transcription. We provide here evidence that Mcm1, a MADS-box protein, is essential for PHO5 mitotic activation. In addition, we found that cells simultaneously lacking the forkhead proteins, Fkh1 and Fkh2, exhibited a 2.5-fold decrease in PHO5 expression. The Mcm1-Fkh2 complex, first shown to transactivate genes within the CLB2 cluster that drive G2/M progression, also associated directly at the PHO5 promoter in a cell cycle-dependent manner in chromatin immunoprecipitation assays. Sds3, a component specific to the Rpd3L histone deacetylase complex, was also recruited to PHO5 in G1. These findings provide (i) further mechanistic insight into PHO5 mitotic activation, (ii) demonstrate that Mcm1-Fkh2 can function combinatorially with other activators to yield late M/G1 induction, and (iii) couple the mitotic cell cycle progression machinery to cellular phosphate homeostasis.

scholarly journals Cdc4 phospho-degrons allow differential regulation of Ame1CENP-U protein stability across the cell cycle

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Miriam Böhm ◽  
Kerstin Killinger ◽  
Alexander Dudziak ◽  
Pradeep Pant ◽  
Karolin Jänen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Building Blocks ◽  
Meiotic Spindle ◽  
Dependent Manner ◽  
Physiological Importance ◽  
Kinetochore Assembly ◽  
Ubiquitin Ligase Complex ◽  
M Phase ◽  
Novel Strategy ◽  
Cycle Dependent

Kinetochores are multi-subunit protein assemblies that link chromosomes to microtubules of the mitotic and meiotic spindle. It is still poorly understood how efficient, centromere-dependent kinetochore assembly is accomplished from hundreds of individual protein building blocks in a cell cycle dependent manner. Here, by combining comprehensive phosphorylation analysis of native Ctf19CCAN subunits with biochemical and functional assays in the model system budding yeast, we demonstrate that Cdk1 phosphorylation activates phospho-degrons on the essential subunit Ame1CENP-U which are recognized by the E3 ubiquitin ligase complex SCF-Cdc4. Gradual phosphorylation of degron motifs culminates in M-Phase and targets the protein for degradation. Binding of the Mtw1Mis12 complex shields the proximal phospho-degron, protecting kinetochore-bound Ame1 from the degradation machinery. Artificially increasing degron strength partially suppresses the temperature-sensitivity of a cdc4 mutant, while overexpression of Ame1-Okp1 is toxic in SCF mutants, demonstrating the physiological importance of this mechanism. We propose that phospho-regulated clearance of excess CCAN subunits facilitates efficient centromere-dependent kinetochore assembly. Our results suggest a novel strategy for how phospho-degrons can be used to regulate the assembly of multi-subunit complexes.

Psc3 cohesin of Schizosaccharomyces pombe: cell cycle analysis and identification of three distinct isoforms

2005 ◽  
Vol 386 (7) ◽  
pp. 613-621 ◽  
Author(s):  
Eduard Ilyushik ◽  
David W. Pryce ◽  
Dawid Walerych ◽  
Tracy Riddell ◽  
Jane A. Wakeman ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Schizosaccharomyces Pombe ◽  
Chromosome Segregation ◽  
Consensus Sequence ◽  
Mitotic Cell ◽  
Start Codon ◽  
Mitotic Cell Cycle ◽  
Post Translational Modification ◽  
Amino Terminal

Abstract Cohesins are a group of proteins that function to mediate correct chromosome segregation, DNA repair and meiotic recombination. This report presents the amino acid sequence for the Schizosaccharomyces pombe cohesin Psc3 based on the translation of the cDNA sequence, showing that the protein is smaller than previously predicted. Interestingly, comparison of the amino acid and DNA coding sequences of Psc3 with fission yeast Rec11 meiotic region-specific recombination activator shows that both intron positioning within the genes and the amino-terminal half of the two proteins are highly conserved. We demonstrate that although the intergenic region upstream of the psc3 + start codon contains a consensus sequence for the cell-cycle regulatory MluI cell-cycle box, psc3 + transcription is not differentially regulated during the mitotic cell cycle. Finally, we demonstrate that an epitope-tagged version of Psc3 undergoes no major changes during the mitotic cell cycle. However, instead we identify at least three distinct isoforms of Psc3, suggesting that post-translational modification of Psc3 contributes to the regulation of cohesion function.

C-terminal domain phosphorylation of ERK3 controlled by Cdk1 and Cdc14 regulates its stability in mitosis

2010 ◽  
Vol 428 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Pierre-Luc Tanguay ◽  
Geneviève Rodier ◽  
Sylvain Meloche
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Mitotic Cell ◽  
Mitogen Activated Protein Kinase ◽  
Phosphorylation Sites ◽  
Dependent Manner ◽  
Cell Extracts ◽  
Cycle Dependent

ERK3 (extracellular-signal-regulated kinase 3) is an atypical MAPK (mitogen-activated protein kinase) that is suggested to play a role in cell-cycle progression and cellular differentiation. However, it is not known whether the function of ERK3 is regulated during the cell cycle. In the present paper, we report that ERK3 is stoichiometrically hyperphosphorylated during entry into mitosis and is dephosphorylated at the M→G1 transition. The phosphorylation of ERK3 is associated with the accumulation of the protein in mitosis. In vitro phosphorylation of a series of ERK3-deletion mutants by mitotic cell extracts revealed that phosphorylation is confined to the unique C-terminal extension of the protein. Using MS analysis, we identified four novel phosphorylation sites, Ser684, Ser688, Thr698 and Ser705, located at the extreme C-terminus of ERK3. All four sites are followed by a proline residue. We have shown that purified cyclin B-Cdk1 (cyclindependent kinase 1) phosphorylates these sites in vitro and demonstrate that Cdk1 acts as a major Thr698 kinase in vivo. Reciprocally, we found that the phosphatases Cdc14A and Cdc14B (Cdc is cell-division cycle) bind to ERK3 and reverse its C-terminal phosphorylation in mitosis. Importantly, alanine substitution of the four C-terminal phosphorylation sites markedly decreased the half-life of ERK3 in mitosis, thereby linking phosphorylation to the stabilization of the kinase. The results of the present study identify a novel regulatory mechanism of ERK3 that operates in a cell-cycle-dependent manner.

First meiosis of early dictyate nuclei from primordial oocytes in mature and activated mouse oocytes

Zygote ◽  
1996 ◽  
Vol 4 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Renata Czolowska ◽  
Andrzej K. Tarkowski
Keyword(s):  
Cell Cycle ◽  
Polar Body ◽  
Metaphase Plate ◽  
Mitotic Cell ◽  
Meiotic Spindle ◽  
Oocyte Nucleus ◽  
Oocyte Activation ◽  
Mouse Oocytes ◽  
First Polar Body ◽  
Female Pronucleus

SummaryNuclei of diplotene (dictyate) primordial oocytes (PO) were transferred to metaphase II oocytes and to activated mouse oocytes using cell fusion techniques. In a metaphase II oocyte, the PO nucleus condenses within 2–3 h to bivalents which become arranged on the first meiotic spindle. After oocyte activation, homologous chromosomes segregate between the oocyte and the first polar body, and a diploid pronucleus-like nucleus reforms from the one set of dyads. This nucleus condenses in the first embryonic mitosis into 40 ‘somatic’ chromosomes which coexist in the common metaphase plate with 20 somatic chromosomes originating from the female pronucleus. Shortening of the time between fusion and activation to about 1 h prevents bivalent differentiation. The PO nucleus condenses only partially and reforms, after oocyte activation, a pronucleus-like nucleus. This nucleus gives rise at the first embryonic mitosis to 20 bivalents which coexist with 20 somatic chromosomes originating from the female pronucleus. A PO nucleus introduced into an activated egg completes the first cell cycle as an intact interphase nucleus. It never condenses in the first embryonic mitosis into bivalents, and undergoes only initial condensation (preceding bivalent differentiation). These results indicate that: (1) condensation into bivalents, meiotic spindle formation and first meiotic division can be greatly accelerated by the introduction of an early diplotene (dictyate) oocyte nucleus into a metaphase II oocyte, and (2) depending on whether the diplotene nucleus enters the first embryonic (mitotic) cell cycle after just initiating or after completing the first meiosis, it gives rise at the first cleavage division to meiotic (bivalents) or ‘somatic’ chromosomes respectively.

scholarly journals PAR-4/LKB1 regulates DNA replication during asynchronous division of the early C. elegans embryo

2014 ◽  
Vol 205 (4) ◽  
pp. 447-455 ◽  
Author(s):  
Laura Benkemoun ◽  
Catherine Descoteaux ◽  
Nicolas T. Chartier ◽  
Lionel Pintard ◽  
Jean-Claude Labbé
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Control Cell ◽  
Cycle Duration ◽  
Cell Stage ◽  
C Elegans ◽  
Stage Embryo ◽  
Regulation Of Cell Cycle

Regulation of cell cycle duration is critical during development, yet the underlying molecular mechanisms are still poorly understood. The two-cell stage Caenorhabditis elegans embryo divides asynchronously and thus provides a powerful context in which to study regulation of cell cycle timing during development. Using genetic analysis and high-resolution imaging, we found that deoxyribonucleic acid (DNA) replication is asymmetrically regulated in the two-cell stage embryo and that the PAR-4 and PAR-1 polarity proteins dampen DNA replication dynamics specifically in the posterior blastomere, independently of regulators previously implicated in the control of cell cycle timing. Our results demonstrate that accurate control of DNA replication is crucial during C. elegans early embryonic development and further provide a novel mechanism by which PAR proteins control cell cycle progression during asynchronous cell division.

Cell-cycle-dependent expression of the STK-1 gene encoding a novel murine putative protein kinase

Gene ◽  
1996 ◽  
Vol 169 (2) ◽  
pp. 197-201 ◽  
Author(s):  
Hitoshi Niwa ◽  
Kuniya Abe ◽  
Takahiro Kunisada ◽  
Ken-ichi Yamamura
Keyword(s):  
Cell Cycle ◽  
Protein Kinase ◽  
Gene Encoding ◽  
Putative Protein ◽  
Cycle Dependent ◽  
Putative Protein Kinase

Developmentally regulated cell cycle dependence of swelling-activated anion channel activity in the mouse embryo

Development ◽  
2001 ◽  
Vol 128 (18) ◽  
pp. 3427-3434 ◽  
Author(s):  
Marika Kolajova ◽  
Mary-Anne Hammer ◽  
Jennifer L. Collins ◽  
Jay M. Baltz
Keyword(s):  
Cell Cycle ◽  
Cell Volume ◽  
Cell Volume Regulation ◽  
Germinal Vesicle ◽  
Anion Channel ◽  
Mouse Embryos ◽  
Organic Osmolytes ◽  
Developmentally Regulated ◽  
Cell Stage ◽  
Cycle Dependent

Anion channels activated by increased cell volume are a nearly ubiquitous mechanism of cell volume regulation, including in early preimplantation mouse embryos. Here, we show that the swelling-activated anion current (ICl,swell) in early mouse embryos is cell-cycle dependent, and also that this dependence is developmentally regulated. ICl,swell is present both in first meiotic prophase (germinal vesicle stage) mouse oocytes and in unfertilized mature oocytes in second meiotic metaphase, and it persists after fertilization though the 1-cell and 2-cell stages. ICl,swell was found to remain unchanged during metaphase at the end of the 1-cell stage. However, ICl,swell decreased during prophase and became nearly undetectable upon entry into metaphase at the end of the 2-cell stage. Entry into prophase/metaphase was required for the decrease in ICl,swell at the end of the 2-cell stage, since it persisted indefinitely in 2-cell embryos arrested in late G2. There is considerable evidence that the channel underlying ICl,swell is not only permeable to inorganic anions, but to organic osmolytes as well. We found a similar pattern of cell cycle and developmental dependence in the 1-cell and 2-cell stages for the swelling-induced increase in permeability to the organic osmolyte glycine. Thus, entry into metaphase deactivates ICl,swell in embryos, but only after developmental progression through the 2-cell stage.

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