scholarly journals Transposon silencing in the Drosophila female germline is essential for genome stability in progeny embryos

2018 ◽  
Vol 1 (5) ◽  
pp. e201800179 ◽  
Author(s):  
Zeljko Durdevic ◽  
Ramesh S Pillai ◽  
Anne Ephrussi
Keyword(s):  
Dna Damage ◽  
Genome Stability ◽  
Egg Production ◽  
Nurse Cells ◽  
Selfish Genetic Elements ◽  
Dna Damage Signaling ◽  
Transposon Silencing ◽  
Early Embryos ◽  
Transient Loss ◽  
Female Germline

The Piwi-interacting RNA pathway functions in transposon control in the germline of metazoans. The conserved RNA helicase Vasa is an essential Piwi-interacting RNA pathway component, but has additional important developmental functions. Here, we address the importance of Vasa-dependent transposon control in the Drosophila female germline and early embryos. We find that transient loss of vasa expression during early oogenesis leads to transposon up-regulation in supporting nurse cells of the fly egg-chamber. We show that elevated transposon levels have dramatic consequences, as de-repressed transposons accumulate in the oocyte where they cause DNA damage. We find that suppression of Chk2-mediated DNA damage signaling in vasa mutant females restores oogenesis and egg production. Damaged DNA and up-regulated transposons are transmitted from the mother to the embryos, which sustain severe nuclear defects and arrest development. Our findings reveal that the Vasa-dependent protection against selfish genetic elements in the nuage of nurse cell is essential to prevent DNA damage–induced arrest of embryonic development.

scholarly journals Transposon silencing in the Drosophila female germline ensures genome stability in progeny embryos

2018 ◽  
Author(s):  
Zeljko Durdevic ◽  
Ramesh S. Pillai ◽  
Anne Ephrussi
Keyword(s):  
Dna Damage ◽  
Genome Stability ◽  
Egg Production ◽  
Germ Line ◽  
Selfish Genetic Elements ◽  
Dna Damage Signaling ◽  
Transposon Silencing ◽  
Transient Loss ◽  
Pirna Pathway ◽  
Female Germline

AbstractThe piRNA pathway functions in transposon control in the germ line of metazoans. The conserved RNA helicase Vasa is an essential piRNA pathway component, but has additional important developmental functions. Here we address the importance of Vasa-dependent transposon control in the Drosophila female germline and early embryos. We find that transient loss of vasa expression during early oogenesis leads to transposon up-regulation in supporting nurse cells of the fly egg-chamber. We show that elevated transposon levels have dramatic consequences, as de-repressed transposons accumulate in the oocyte where they cause DNA damage. We find that suppression of Chk2-mediated DNA damage signaling in vasa mutant females restores oogenesis and egg production. Damaged DNA and up-regulated transposons are transmitted from the mother to the embryos, which sustain severe nuclear defects and arrest development. Our findings reveal that the Vasa-dependent protection against selfish genetic elements in the nuage of nurse cell is essential to prevent DNA damage-induced arrest of embryonic development.

scholarly journals Role of Deubiquitinating Enzymes in DNA Repair

2015 ◽  
Vol 36 (4) ◽  
pp. 524-544 ◽  
Author(s):  
Younghoon Kee ◽  
Tony T Huang
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Mammalian Cells ◽  
Genome Stability ◽  
Regulatory Mechanisms ◽  
Deubiquitinating Enzymes ◽  
Genome Maintenance ◽  
Dna Damage Signaling ◽  
Damage Response

Both proteolytic and nonproteolytic functions of ubiquitination are essential regulatory mechanisms for promoting DNA repair and the DNA damage response in mammalian cells. Deubiquitinating enzymes (DUBs) have emerged as key players in the maintenance of genome stability. In this minireview, we discuss the recent findings on human DUBs that participate in genome maintenance, with a focus on the role of DUBs in the modulation of DNA repair and DNA damage signaling.

scholarly journals The role of ATXR6 expression in modulating genome stability and transposable element repression in Arabidopsis

2022 ◽  
Vol 119 (3) ◽  
pp. e2115570119
Author(s):  
Magdalena E. Potok ◽  
Zhenhui Zhong ◽  
Colette L. Picard ◽  
Qikun Liu ◽  
Truman Do ◽  
...  
Keyword(s):  
Dna Damage ◽  
Genome Stability ◽  
Null Allele ◽  
Epigenetic Changes ◽  
Germline Development ◽  
Tissue Specific ◽  
Damage Response ◽  
Female Germline

ARABIDOPSIS TRITHORAX-RELATED PROTEIN 5 (ATXR5) AND ATXR6 are required for the deposition of H3K27me1 and for maintaining genomic stability in Arabidopsis. Reduction of ATXR5/6 activity results in activation of DNA damage response genes, along with tissue-specific derepression of transposable elements (TEs), chromocenter decompaction, and genomic instability characterized by accumulation of excess DNA from heterochromatin. How loss of ATXR5/6 and H3K27me1 leads to these phenotypes remains unclear. Here we provide extensive characterization of the atxr5/6 hypomorphic mutant by comprehensively examining gene expression and epigenetic changes in the mutant. We found that the tissue-specific phenotypes of TE derepression and excessive DNA in this atxr5/6 mutant correlated with residual ATXR6 expression from the hypomorphic ATXR6 allele. However, up-regulation of DNA damage genes occurred regardless of ATXR6 levels and thus appears to be a separable process. We also isolated an atxr6-null allele which showed that ATXR5 and ATXR6 are required for female germline development. Finally, we characterize three previously reported suppressors of the hypomorphic atxr5/6 mutant and show that these rescue atxr5/6 via distinct mechanisms, two of which involve increasing H3K27me1 levels.

Maintenance of Genome Stability and Breast Cancer: Molecular Analysis of DNA Damage-Activated Kinases

2007 ◽  
Author(s):  
Heather L. Ball ◽  
Mark Ehrhardt ◽  
Daniel Mordes ◽  
David Cortez
Keyword(s):  
Breast Cancer ◽  
Dna Damage ◽  
Molecular Analysis ◽  
Genome Stability

scholarly journals PRL3 induces polypoid giant cancer cells eliminated by PRL3-zumab to reduce tumor relapse

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Min Thura ◽  
Zu Ye ◽  
Abdul Qader Al-Aidaroos ◽  
Qiancheng Xiong ◽  
Jun Yi Ong ◽  
...  
Keyword(s):  
Dna Damage ◽  
Stem Cell ◽  
Cancer Cells ◽  
Embryonic Stem ◽  
Genotoxic Stress ◽  
Stem Cell Markers ◽  
Tumor Removal ◽  
Primary Tumors ◽  
Tumor Relapse ◽  
Dna Damage Signaling

AbstractPRL3, a unique oncotarget, is specifically overexpressed in 80.6% of cancers. In 2003, we reported that PRL3 promotes cell migration, invasion, and metastasis. Herein, firstly, we show that PRL3 induces Polyploid Giant Cancer Cells (PGCCs) formation. PGCCs constitute stem cell-like pools to facilitate cell survival, chemo-resistance, and tumor relapse. The correlations between PRL3 overexpression and PGCCs attributes raised possibilities that PRL3 could be involved in PGCCs formation. Secondly, we show that PRL3+ PGCCs co-express the embryonic stem cell markers SOX2 and OCT4 and arise mainly due to incomplete cytokinesis despite extensive DNA damage. Thirdly, we reveal that PRL3+ PGCCs tolerate prolonged chemotherapy-induced genotoxic stress via suppression of the pro-apoptotic ATM DNA damage-signaling pathway. Fourthly, we demonstrated PRL3-zumab, a First-in-Class humanized antibody drug against PRL3 oncotarget, could reduce tumor relapse in ‘tumor removal’ animal model. Finally, we confirmed that PGCCs were enriched in relapse tumors versus primary tumors. PRL3-zumab has been approved for Phase 2 clinical trials in Singapore, US, and China to block all solid tumors. This study further showed PRL3-zumab could potentially serve an ‘Adjuvant Immunotherapy’ after tumor removal surgery to eliminate PRL3+ PGCC stem-like cells, preventing metastasis and relapse.

scholarly journals Eukaryotic clamp loaders and unloaders in the maintenance of genome stability

2020 ◽  
Vol 52 (12) ◽  
pp. 1948-1958
Author(s):  
Kyoo-young Lee ◽  
Su Hyung Park
Keyword(s):  
Dna Damage ◽  
Genomic Instability ◽  
Genome Stability ◽  
Critical Role ◽  
Nuclear Antigen ◽  
Checkpoint Activation ◽  
Sliding Clamp ◽  
Clamp Loaders ◽  
Factor C

AbstractEukaryotic sliding clamp proliferating cell nuclear antigen (PCNA) plays a critical role as a processivity factor for DNA polymerases and as a binding and acting platform for many proteins. The ring-shaped PCNA homotrimer and the DNA damage checkpoint clamp 9-1-1 are loaded onto DNA by clamp loaders. PCNA can be loaded by the pentameric replication factor C (RFC) complex and the CTF18-RFC-like complex (RLC) in vitro. In cells, each complex loads PCNA for different purposes; RFC-loaded PCNA is essential for DNA replication, while CTF18-RLC-loaded PCNA participates in cohesion establishment and checkpoint activation. After completing its tasks, PCNA is unloaded by ATAD5 (Elg1 in yeast)-RLC. The 9-1-1 clamp is loaded at DNA damage sites by RAD17 (Rad24 in yeast)-RLC. All five RFC complex components, but none of the three large subunits of RLC, CTF18, ATAD5, or RAD17, are essential for cell survival; however, deficiency of the three RLC proteins leads to genomic instability. In this review, we describe recent findings that contribute to the understanding of the basic roles of the RFC complex and RLCs and how genomic instability due to deficiency of the three RLCs is linked to the molecular and cellular activity of RLC, particularly focusing on ATAD5 (Elg1).

scholarly journals Germ granule dysfunction is a hallmark and mirror of Piwi mutant sterility

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maya Spichal ◽  
Bree Heestand ◽  
Katherine Kretovich Billmyre ◽  
Stephen Frenk ◽  
Craig C. Mello ◽  
...  
Keyword(s):  
Dna Damage ◽  
Genomic Instability ◽  
Environmental Restoration ◽  
Related Gene ◽  
C Elegans ◽  
Dna Damage Signaling ◽  
Multiple Phenotypes ◽  
Granule Structure ◽  
Germ Granules ◽  
Late Generation

AbstractIn several species, Piwi/piRNA genome silencing defects cause immediate sterility that correlates with transposon expression and transposon-induced genomic instability. In C. elegans, mutations in the Piwi-related gene (prg-1) and other piRNA deficient mutants cause a transgenerational decline in fertility over a period of several generations. Here we show that the sterility of late generation piRNA mutants correlates poorly with increases in DNA damage signaling. Instead, sterile individuals consistently exhibit altered perinuclear germ granules. We show that disruption of germ granules does not activate transposon expression but induces multiple phenotypes found in sterile prg-1 pathway mutants. Furthermore, loss of the germ granule component pgl-1 enhances prg-1 mutant infertility. Environmental restoration of germ granule function for sterile pgl-1 mutants restores their fertility. We propose that Piwi mutant sterility is a reproductive arrest phenotype that is characterized by perturbed germ granule structure and is phenocopied by germ granule dysfunction, independent of genomic instability.

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