scholarly journals CDK Regulation of Meiosis: Lessons from S. cerevisiae and S. pombe

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 723
Author(s):  
Anne M. MacKenzie ◽  
Soni Lacefield
Keyword(s):  
Fission Yeast ◽  
Yeast Species ◽  
Regulatory System ◽  
Cyclin Dependent Kinase ◽  
Post Translational Modifications ◽  
Regulatory Subunits ◽  
Meiotic Progression ◽  
The Past ◽  
Cdk Regulation

Meiotic progression requires precise orchestration, such that one round of DNA replication is followed by two meiotic divisions. The order and timing of meiotic events is controlled through the modulation of the phosphorylation state of proteins. Key components of this phospho-regulatory system include cyclin-dependent kinase (CDK) and its cyclin regulatory subunits. Over the past two decades, studies in budding and fission yeast have greatly informed our understanding of the role of CDK in meiotic regulation. In this review, we provide an overview of how CDK controls meiotic events in both budding and fission yeast. We discuss mechanisms of CDK regulation through post-translational modifications and changes in the levels of cyclins. Finally, we highlight the similarities and differences in CDK regulation between the two yeast species. Since CDK and many meiotic regulators are highly conserved, the findings in budding and fission yeasts have revealed conserved mechanisms of meiotic regulation among eukaryotes.

scholarly journals A Novel Role of Dma1 in Regulating Forespore Membrane Assembly and Sporulation in Fission Yeast

2010 ◽  
Vol 21 (24) ◽  
pp. 4349-4360 ◽  
Author(s):  
Wen-zhu Li ◽  
Zhi-yong Yu ◽  
Peng-fei Ma ◽  
Yamei Wang ◽  
Quan-wen Jin
Keyword(s):  
Fission Yeast ◽  
Mitotic Spindle ◽  
Nuclear Division ◽  
Scaffold Proteins ◽  
Related Protein ◽  
Membrane Assembly ◽  
Meiotic Progression ◽  
Septation Initiation Network ◽  
Specific Proteins

In fission yeast Schizosaccharomyces pombe, a diploid mother cell differentiates into an ascus containing four haploid ascospores following meiotic nuclear divisions, through a process called sporulation. Several meiosis-specific proteins of fission yeast have been identified to play essential roles in meiotic progression and sporulation. We report here an unexpected function of mitotic spindle checkpoint protein Dma1 in proper spore formation. Consistent with its function in sporulation, expression of dma1+ is up-regulated during meiosis I and II. We showed that Dma1 localizes to the SPB during meiosis and the maintenance of this localization at meiosis II depends on septation initiation network (SIN) scaffold proteins Sid4 and Cdc11. Cells lacking Dma1 display defects associated with sporulation but not nuclear division, leading frequently to formation of asci with fewer spores. Our genetic analyses support the notion that Dma1 functions in parallel with the meiosis-specific Sid2-related protein kinase Slk1/Mug27 and the SIN signaling during sporulation, possibly through regulating proper forespore membrane assembly. Our studies therefore revealed a novel function of Dma1 in regulating sporulation in fission yeast.

Post-translational modifications of lysine in DNA-damage repair

2012 ◽  
Vol 52 ◽  
pp. 93-111 ◽  
Author(s):  
Snehajyoti Chatterjee ◽  
Parijat Senapati ◽  
Tapas K. Kundu
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Post Translational Modifications ◽  
Dna Repair Mechanisms ◽  
The Past ◽  
Damage Repair ◽  
Lysine Residues ◽  
Repair Mechanisms ◽  
Genotoxic Insult

DNA damage in cells is often the result of constant genotoxic insult. Nevertheless, efficient DNA repair pathways are able to maintain genomic integrity. Over the past decade it has been revealed that it is not only kinase signalling pathways which play a central role in this process, but also the different post-translational modifications at lysine residues of histone (chromatin) and non-histone proteins. These lysine modifications include acetylation, methylation, ubiquitination and SUMOylation. Genomic instability is often the major cause of different diseases, especially cancer, where lysine modifications are altered and thereby have an impact on the various DNA repair mechanisms. This chapter will discuss the recent advances in our understanding of the role of different lysine modifications in DNA repair and its physiological consequences.

scholarly journals The Clp1/Cdc14 phosphatase contributes to the robustness of cytokinesis by association with anillin-related Mid1

2008 ◽  
Vol 181 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Dawn M. Clifford ◽  
Benjamin A. Wolfe ◽  
Rachel H. Roberts-Galbraith ◽  
W. Hayes McDonald ◽  
John R. Yates ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Cell Cycle Control ◽  
Physical Property ◽  
Cyclin Dependent Kinase ◽  
Contractile Ring ◽  
Protein Mobility ◽  
Functional Consequences

Cdc14 phosphatases antagonize cyclin-dependent kinase–directed phosphorylation events and are involved in several facets of cell cycle control. We investigate the role of the fission yeast Cdc14 homologue Clp1/Flp1 in cytokinesis. We find that Clp1/Flp1 is tethered at the contractile ring (CR) through its association with anillin-related Mid1. Fluorescent recovery after photobleaching analyses indicate that Mid1, unlike other tested CR components, is anchored at the cell midzone, and this physical property is likely to account for its scaffolding role. By generating a mutation in mid1 that selectively disrupts Clp1/Flp1 tethering, we reveal the specific functional consequences of Clp1/Flp1 activity at the CR, including dephosphorylation of the essential CR component Cdc15, reductions in CR protein mobility, and CR resistance to mild perturbation. Our evidence indicates that Clp1/Flp1 must interact with the Mid1 scaffold to ensure the fidelity of Schizosaccharomyces pombe cytokinesis.

scholarly journals VPS38/UVRAG and ATG14, the variant regulatory subunits of the ATG6/Beclin1-PI3K complexes, are crucial for the biogenesis of the yolk organelles and are transcriptionally regulated in the oocytes of the vector Rhodnius prolixus

2021 ◽  
Vol 15 (9) ◽  
pp. e0009760
Author(s):  
Priscila H. Vieira ◽  
Claudia F. Benjamim ◽  
Georgia Atella ◽  
Isabela Ramos
Keyword(s):  
Complex I ◽  
Regulatory System ◽  
Rhodnius Prolixus ◽  
Insect Vector ◽  
Class Iii ◽  
Yolk Proteins ◽  
Regulatory Subunits ◽  
Complex Ii ◽  
Transcriptional Regulatory

In insects the reserve proteins are stored in the oocytes into endocytic-originated vesicles named yolk organelles. VPS38/UVRAG and ATG14 are the variant regulatory subunits of two class-III ATG6/Beclin1 PI3K complexes that regulate the recruitment of the endocytic (complex II) and autophagic (complex I) machineries. In a previous work from our group, we found that the silencing of ATG6/Beclin1 resulted in the formation of yolk-deficient oocytes due to defects in the endocytosis of the yolk proteins. Because ATG6/Beclin1 is present in the two above-described PI3K complexes, we could not identify the contributions of each complex to the yolk defective phenotypes. To address this, here we investigated the role of the variant subunits VPS38/UVRAG (complex II, endocytosis) and ATG14 (complex I, autophagy) in the biogenesis of the yolk organelles in the insect vector of Chagas Disease Rhodnius prolixus. Interestingly, the silencing of both genes phenocopied the silencing of ATG6/Beclin1, generating 1) accumulation of yolk proteins in the hemolymph; 2) white, smaller, and yolk-deficient oocytes; 3) abnormal yolk organelles in the oocyte cortex; and 4) unviable F1 embryos. However, we found that the similar phenotypes were the result of a specific cross-silencing effect among the PI3K subunits where the silencing of VPS38/UVRAG and ATG6/Beclin1 resulted in the specific silencing of each other, whereas the silencing of ATG14 triggered the silencing of all three PI3K components. Because the silencing of VPS38/UVRAG and ATG6/Beclin1 reproduced the yolk-deficiency phenotypes without the cross silencing of ATG14, we concluded that the VPS38/UVRAG PI3K complex II was the major contributor to the previously observed phenotypes in silenced insects. Altogether, we found that class-III ATG6/Beclin1 PI3K complex II (VPS38/UVRAG) is essential for the yolk endocytosis and that the subunits of both complexes are under an unknown transcriptional regulatory system.

scholarly journals Critical Functions of PP2A-Like Protein Phosphotases in Regulating Meiotic Progression

2021 ◽  
Vol 9 ◽  
Author(s):  
Wen-Long Lei ◽  
Wei-Ping Qian ◽  
Qing-Yuan Sun
Keyword(s):  
Birth Defects ◽  
Protein Phosphatase ◽  
Dynamic Equilibrium ◽  
Protein Phosphatases ◽  
Meiotic Cell ◽  
Single Cycle ◽  
Post Translational Modifications ◽  
Meiotic Progression ◽  
Protein Dephosphorylation

Meiosis is essential to the continuity of life in sexually-reproducing organisms through the formation of haploid gametes. Unlike somatic cells, the germ cells undergo two successive rounds of meiotic divisions after a single cycle of DNA replication, resulting in the decrease in ploidy. In humans, errors in meiotic progression can cause infertility and birth defects. Post-translational modifications, such as phosphorylation, ubiquitylation and sumoylation have emerged as important regulatory events in meiosis. There are dynamic equilibrium of protein phosphorylation and protein dephosphorylation in meiotic cell cycle process, regulated by a conservative series of protein kinases and protein phosphatases. Among these protein phosphatases, PP2A, PP4, and PP6 constitute the PP2A-like subfamily within the serine/threonine protein phosphatase family. Herein, we review recent discoveries and explore the role of PP2A-like protein phosphatases during meiotic progression.

scholarly journals Post-translational modifications of CDK5 and their biological roles in cancer

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Gui-Bin Gao ◽  
Yue Sun ◽  
Run-Dong Fang ◽  
Ying Wang ◽  
Yang Wang ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Malignant Tumors ◽  
Biological Significance ◽  
Cyclin Dependent Kinase ◽  
Antitumor Effects ◽  
Aberrant Expression ◽  
Post Translational Modifications ◽  
Atypical Member ◽  
Cyclin Dependent Kinase 5

AbstractPost-translational modifications (PTMs) of Cyclin-dependent kinase 5 (CDK5) have emerged as important regulatory mechanisms that modulate cancer development in patients. Though CDK5 is an atypical member of the cyclin-dependent kinase family, its aberrant expression links to cell proliferation, DNA damage response, apoptosis, migration and angiogenesis in cancer. Current studies suggested that, new PTMs on CDK5, including S-nitrosylation, sumoylation, and acetylation, serve as molecular switches to control the kinase activity of CDK5 in the cell. However, a majority of these modifications and their biological significance in cancer remain uncharacterized. In this review, we discussed the role of PTMs on CDK5-mediated signaling cascade, and their possible mechanisms of action in malignant tumors, as well as the challenges and future perspectives in this field. On the basis of the newly identified regulatory signaling pathways of CDK5 related to PTMs, researchers have investigated the cancer therapeutic potential of chemical compounds, small-molecule inhibitors, and competitive peptides by targeting CDK5 and its PTMs. Results of these preclinical studies demonstrated that targeting PTMs of CDK5 yields promising antitumor effects and that clinical translation of these therapeutic strategies is warranted.

Beyond the walls of the nucleus: the role of histones in cellular signaling and innate immunityThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.

2006 ◽  
Vol 84 (4) ◽  
pp. 589-595 ◽  
Author(s):  
Missag H. Parseghian ◽  
Keith A. Luhrs
Keyword(s):  
Antimicrobial Agents ◽  
Peer Review Process ◽  
Vital Role ◽  
Surface Acting ◽  
Microbial Infection ◽  
Post Translational Modifications ◽  
Linker Histones ◽  
The Past ◽  
Critical Components

Although they are one of the oldest family of proteins known (first described in 1884 by Kossel), histones continue to surprise researchers with their ever expanding roles in biology. In the past 25 years, the view of core histone octamers as a simple spool around which DNA in the nucleus is wound and linker histones as mere fasteners clipping it all together has transformed into the realization that histones play a vital role in transcriptional regulation. Through post-translational modifications, histones control the accessibility of transcription factors and a host of other proteins to multiple, conceivably thousands of, genes at once. While researchers have spent decades deciphering the role of histones in the overall structure of chromatin, it might surprise some to find that an entirely separate faction of scientists have focused on the role of histones beyond the confines of the nuclear envelope. In the past decade, there has been an accumulation of observations that suggest that histones can be found at the mitochondrion during the onset of apoptotic signaling and even at the cell surface, acting as a receptor for bacterial and viral proteins. More provocatively, immunologists are becoming convinced that they can also be found in the lumen of several tissues, acting as antimicrobial agents—critical components of an ancient innate immune system. Perhaps nowhere is this observation as dramatic as in the ability of neutrophils to entrap bacterial pathogens by casting out "nets" of DNA and histones that not only act as a physical barrier, but also display bactericidal activity. As our views regarding the role of histones inside and outside the cell evolve, some have begun to develop therapies that either utilize or target histones in the fight against cancer, microbial infection, and autoimmune disease. It is our goal here to begin the process of merging the dichotomous lives of histones both within and without the nuclear membrane.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

A literature review on firms' internationalisation through e-commerce

2019 ◽  
pp. 121-143
Author(s):  
Riccardo Resciniti ◽  
Federica De Vanna
Keyword(s):  
Systematic Review ◽  
Literature Review ◽  
International Business ◽  
Decision Process ◽  
Foreign Markets ◽  
New Markets ◽  
Integrative Framework ◽  
The Past ◽  
The Relationship

The rise of e-commerce has brought considerable changes to the relationship between firms and consumers, especially within international business. Hence, understanding the use of such means for entering foreign markets has become critical for companies. However, the research on this issue is new and so it is important to evaluate what has been studied in the past. In this study, we conduct a systematic review of e-commerce and internationalisation studies to explicate how firms use e-commerce to enter new markets and to export. The studies are classified by theories and methods used in the literature. Moreover, we draw upon the internationalisation decision process (antecedents-modalities-consequences) to propose an integrative framework for understanding the role of e-commerce in internationalisation

Concealment of Illegally Obtained Assets in Nigeria: Revisiting the Role of the Churches in Money Laundering

2020 ◽  
Vol 28 (1) ◽  
pp. 106-121
Author(s):  
Kato Gogo Kingston
Keyword(s):  
Economic Growth ◽  
Money Laundering ◽  
Financial Crime ◽  
The Past ◽  
Key Drivers ◽  
Nigerian Government

Financial crime in Nigeria – including money laundering – is ravaging Nigeria's economic growth. In the past few years, the Nigerian government has made efforts to tackle money laundering by enacting laws and setting up several agencies to enforce the laws. However, there are substantial loopholes in the regulatory and enforcement regimes. This article seeks to unravel the involvement of the churches as key drivers in money laundering crimes in Nigeria. It concludes that the permissive secrecy which enables churches to conceal the names of their financiers and donors breeds criminality on an unimaginable scale.

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