p21-activated kinase 1 activity is required for histone H3 Ser10 phosphorylation and chromatin condensation in mouse oocyte meiosis

2017 ◽  
Vol 29 (7) ◽  
pp. 1287 ◽  
Author(s):  
Nana Zhang ◽  
Xiuhong Li ◽  
Xiaoyun Liu ◽  
Yan Cao ◽  
Dandan Chen ◽  
...  
Keyword(s):  
Chromatin Condensation ◽  
Histone H3 ◽  
Concomitant Administration ◽  
Competitive Inhibitor ◽  
Subcellular Localisation ◽  
H3 Phosphorylation ◽  
Oocyte Meiosis ◽  
P21 Activated Kinase ◽  
And Function ◽  
Pak1 Activation

p21-activated kinase 1 (Pak1) is essential for a variety of cellular events, including gene transcription, cytoskeletal organisation, cell proliferation and apoptosis. Pak1 is activated upon autophosphorylation on many amino residues; in particular, phosphorylation on Thr423 maintains maximal Pak1 activation. In the present study we investigated the protein expression, subcellular localisation and function of Pak1 phosphorylated on Thr423 (pPak1Thr423) in mouse oocytes. pPak1Thr423 was detected upon meiotic resumption and localised on the condensing chromatin. Thr423 phosphorylation was markedly suppressed by the Pak1 ATP-competitive inhibitor PF-3758309, but not by the allosteric inhibitors IPA-3 (2.5 μM and 10 μM) (1, 1′-dithiobis-2-naphthalenol) and TAT-PAK18 (10 μM), which prevent the binding of Pak1 to its upstream activators GTPase Cdc42/Rac and Pak-interacting exchange factor (PIX), respectively, implying that Pak1 activation may be independent of GTPase and PIX in oocyte meiosis. Inhibition of Pak1 activation concomitantly restrained histone H3 phosphorylation on Ser10 and consequently inhibited chromatin condensation; however, this phenotype was reversed by concomitant administration of the Pak1 activator FTY720. The changes in the pattern of expression of phosphorylated extracellular signal-regulated kinase 1/2 in response to PF-3758309 or FTY720 were the same as seen for pPak1Thr423. These results show that activated Pak1 regulates chromatin condensation by promoting H3 Ser10 phosphorylation in oocytes after the resumption of meiotic progression.

scholarly journals Helicase LSH/Hells regulates kinetochore function, histone H3/Thr3 phosphorylation and centromere transcription during oocyte meiosis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Claudia Baumann ◽  
Wei Ma ◽  
Xiaotian Wang ◽  
Muthugapatti K. Kandasamy ◽  
Maria M. Viveiros ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Genome Stability ◽  
Histone H3 ◽  
Major Satellite ◽  
Targeted Deletion ◽  
H3 Phosphorylation ◽  
Oocyte Meiosis ◽  
Nuclear Domains ◽  
Histone H3 Phosphorylation ◽  
Kinetochore Function

Abstract Centromeres are epigenetically determined nuclear domains strictly required for chromosome segregation and genome stability. However, the mechanisms regulating centromere and kinetochore chromatin modifications are not known. Here, we demonstrate that LSH is enriched at meiotic kinetochores and its targeted deletion induces centromere instability and abnormal chromosome segregation. Superresolution chromatin analysis resolves LSH at the inner centromere and kinetochores during oocyte meiosis. LSH knockout pachytene oocytes exhibit reduced HDAC2 and DNMT-1. Notably, mutant oocytes show a striking increase in histone H3 phosphorylation at threonine 3 (H3T3ph) and accumulation of major satellite transcripts in both prophase-I and metaphase-I chromosomes. Moreover, knockout oocytes exhibit centromere fusions, ectopic kinetochore formation and abnormal exchange of chromatin fibers between paired bivalents and asynapsed chromosomes. Our results indicate that loss of LSH affects the levels and chromosomal localization of H3T3ph and provide evidence that, by maintaining transcriptionally repressive heterochromatin, LSH may be essential to prevent deleterious meiotic recombination events at repetitive centromeric sequences.

scholarly journals Mitotic Histone H3 Phosphorylation by Vaccinia-Related Kinase 1 in Mammalian Cells

2007 ◽  
Vol 27 (24) ◽  
pp. 8533-8546 ◽  
Author(s):  
Tae-Hong Kang ◽  
Do-Young Park ◽  
Yoon Ha Choi ◽  
Kyung-Jin Kim ◽  
Ho Sup Yoon ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Chromatin Condensation ◽  
Histone H3 ◽  
Cycle Phase ◽  
Aurora B ◽  
H3 Phosphorylation ◽  
Histone H3 Phosphorylation

ABSTRACT Mitotic chromatin condensation is essential for cell division in eukaryotes. Posttranslational modification of the N-terminal tail of histone proteins, particularly by phosphorylation by mitotic histone kinases, may facilitate this process. In mammals, aurora B is believed to be the mitotic histone H3 Ser10 kinase; however, it is not sufficient to phosphorylate H3 Ser10 with aurora B alone. We show that histone H3 is phosphorylated by vaccinia-related kinase 1 (VRK1). Direct phosphorylation of Thr3 and Ser10 in H3 by VRK1 both in vitro and in vivo was observed. Loss of VRK1 activity was associated with a marked decrease in H3 phosphorylation during mitosis. Phosphorylation of Ser10 by VRK1 is similar to that by aurora B. Moreover, expression and chromatin localization of VRK1 depended on the cell cycle phase. Overexpression of VRK1 resulted in a dramatic condensation of nuclei. Our findings collectively support a role of VRK1 as a novel mitotic histone H3 kinase in mammals.

scholarly journals Impact of DNA methylation on 3D genome structure

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Diana Buitrago ◽  
Mireia Labrador ◽  
Juan Pablo Arcon ◽  
Rafael Lema ◽  
Oscar Flores ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Chromatin Structure ◽  
Chromatin Condensation ◽  
Genome Structure ◽  
Dna Methyltransferases ◽  
Model System ◽  
Structure And Function ◽  
3D Genome ◽  
Cellular Machinery ◽  
And Function

AbstractDetermining the effect of DNA methylation on chromatin structure and function in higher organisms is challenging due to the extreme complexity of epigenetic regulation. We studied a simpler model system, budding yeast, that lacks DNA methylation machinery making it a perfect model system to study the intrinsic role of DNA methylation in chromatin structure and function. We expressed the murine DNA methyltransferases in Saccharomyces cerevisiae and analyzed the correlation between DNA methylation, nucleosome positioning, gene expression and 3D genome organization. Despite lacking the machinery for positioning and reading methylation marks, induced DNA methylation follows a conserved pattern with low methylation levels at the 5’ end of the gene increasing gradually toward the 3’ end, with concentration of methylated DNA in linkers and nucleosome free regions, and with actively expressed genes showing low and high levels of methylation at transcription start and terminating sites respectively, mimicking the patterns seen in mammals. We also see that DNA methylation increases chromatin condensation in peri-centromeric regions, decreases overall DNA flexibility, and favors the heterochromatin state. Taken together, these results demonstrate that methylation intrinsically modulates chromatin structure and function even in the absence of cellular machinery evolved to recognize and process the methylation signal.

scholarly journals Cytoplasmic dynein participates in meiotic checkpoint inactivation in mouse oocytes by transporting cytoplasmic mitotic arrest-deficient (Mad) proteins from kinetochores to spindle poles

Reproduction ◽  
2007 ◽  
Vol 133 (4) ◽  
pp. 685-695 ◽  
Author(s):  
Dong Zhang ◽  
Shen Yin ◽  
Man-Xi Jiang ◽  
Wei Ma ◽  
Yi Hou ◽  
...  
Keyword(s):  
Spindle Checkpoint ◽  
Germinal Vesicle ◽  
Cytoplasmic Dynein ◽  
Mitotic Arrest ◽  
Checkpoint Proteins ◽  
Meiotic Progression ◽  
Spindle Poles ◽  
Anaphase Onset ◽  
Oocyte Meiosis ◽  
And Function

The present study was designed to investigate the localization and function of cytoplasmic dynein (dynein) during mouse oocyte meiosis and its relationship with two major spindle checkpoint proteins, mitotic arrest-deficient (Mad) 1 and Mad2. Oocytes at various stages during the first meiosis were fixed and immunostained for dynein, Mad1, Mad2, kinetochores, microtubules, and chromosomes. Some oocytes were treated with nocodazole before examination. Anti-dynein antibody was injected into the oocytes at germinal vesicle (GV) stage before the examination of its effects on meiotic progression or Mad1 and Mad2 localization. Results showed that dynein was present in the oocytes at various stages from GV to metaphase II and the locations of Mad1 and Mad2 were associated with dynein’s movement. Both Mad1 and Mad2 had two existing states: one existed in the cytoplasm (cytoplasmic Mad1 or cytoplasmic Mad2), which did not bind to kinetochores, while the other bound to kinetochores (kinetochore Mad1 or kinetochore Mad2). The equilibrium between the two states varied during meiosis and/or in response to the changes of the connection between microtubules and kinetochores. Cytoplasmic Mad1 and Mad2 recruited to chromosomes when the connection between microtubules and chromosomes was destroyed. Inhibition of dynein interferes with cytoplasmic Mad1 and Mad2 transportation from chromosomes to spindle poles, thus inhibits checkpoint silence and delays anaphase onset. These results indicate that dynein may play a role in spindle checkpoint inactivation.

scholarly journals Expression and function of the novel proto-oncogene PBF in thyroid cancer: a new target for augmenting radioiodine uptake

2011 ◽  
Vol 210 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Vicki E Smith ◽  
Jayne A Franklyn ◽  
Christopher J McCabe
Keyword(s):  
Thyroid Cancer ◽  
Current Data ◽  
Subcellular Localisation ◽  
Sodium Iodide Symporter ◽  
Iodide Uptake ◽  
Radioiodine Uptake ◽  
Novel Target ◽  
And Function

Pituitary tumor-transforming gene (PTTG)-binding factor (PBF; PTTG1IP) was initially identified through its interaction with the human securin, PTTG. Like PTTG, PBF is upregulated in multiple endocrine tumours including thyroid cancer. PBF is believed to induce the translocation of PTTG into the cell nucleus where it can drive tumourigenesis via a number of different mechanisms. However, an independent transforming ability has been demonstrated both in vitro and in vivo, suggesting that PBF is itself a proto-oncogene. Studied in only a limited number of publications to date, PBF is emerging as a protein with a growing repertoire of roles. Recent data suggest that PBF possesses a complex multifunctionality in an increasing number of tumour settings. For example, PBF is upregulated by oestrogen and mediates oestrogen-stimulated cell invasion in breast cancer cells. In addition to a possible role in the induction of thyroid tumourigenesis, PBF overexpression in thyroid cancers inhibits iodide uptake. PBF has been shown to repress sodium iodide symporter (NIS) activity by transcriptional regulation of NIS expression through the human NIS upstream enhancer and further inhibits iodide uptake via a post-translational mechanism of NIS governing subcellular localisation. This review discusses the current data describing PBF expression and function in thyroid cancer and highlights PBF as a novel target for improving radioiodine uptake and thus prognosis in thyroid cancer.

scholarly journals Glutamate induces histone H3 phosphorylation but not acetylation in striatal neurons: role of mitogen- and stress-activated kinase-1

2006 ◽  
Vol 101 (3) ◽  
pp. 697-708 ◽  
Author(s):  
Karen Brami-Cherrier ◽  
Jeremie Lavaur ◽  
Christiane Pagès ◽  
J. Simon C. Arthur ◽  
Jocelyne Caboche
Keyword(s):  
Histone H3 ◽  
Striatal Neurons ◽  
H3 Phosphorylation ◽  
Histone H3 Phosphorylation
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