Methods in molecular biology, Journal Year: 2024, Volume and Issue: unknown, P. 11 - 22
Published: Sept. 16, 2024
Language: Английский
Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)
Published: Sept. 6, 2024
Language: Английский
Citations
5
Viruses, Journal Year: 2024, Volume and Issue: 16(5), P. 764 - 764
Published: May 11, 2024
The hepatitis B virus (HBV) infects hepatocytes and hijacks host cellular mechanisms for its replication. Host proteins can be frontline effectors of the cell’s defense restrict viral replication by impeding multiple steps during intracellular lifecycle. This review summarizes many well-described restriction factors, their restriction, counteractive measures HBV, with a special focus on transcription. We discuss some limitations knowledge gaps about highlighting how these factors may harnessed to facilitate therapeutic strategies against HBV.
Language: Английский
Citations
4
Nature Cell Biology, Journal Year: 2024, Volume and Issue: 27(1), P. 118 - 129
Published: Oct. 31, 2024
DNA double-strand breaks (DSBs) must be repaired to ensure genome stability. Crucially, DSB-ends kept together for timely repair. In Saccharomyces cerevisiae, two pathways mediate DSB end-tethering. One employs the Mre11–Rad50–Xrs2 (MRX) complex physically bridge DSB-ends. Another requires conversion of into single-strand (ssDNA) by Exo1, but bridging proteins are unknown. We uncover that cohesin, its loader and Smc5/6 act with Exo1 tether Remarkably, cohesin specifically impaired in oligomerization fails DSB-ends, revealing a function oligomerization. addition known importance sister chromatid cohesion, microscopy-based microfluidic experiments unveil role repair ensuring Altogether, our findings demonstrate prevents end-separation promotes repair, previously undescribed mode action safeguarding integrity. Phipps et al. report cohesin-dependent break (DSB) end-tethering mechanism SMC5/6 budding yeast. They show genomic
Language: Английский
Citations
4
Biomolecules, Journal Year: 2025, Volume and Issue: 15(6), P. 755 - 755
Published: May 23, 2025
The SMC-5/6 complex safeguards genome stability through the coordinated action of its core SMC proteins and associated NSE subunits. NSE-1 is a key component essential for DNA repair, yet it remains poorly characterized in Caenorhabditis elegans. To further elucidate functional mechanisms NSE-1, we performed an EMS-based forward genetic screen nse-1::gfp(wsh1) reporter strain to identify mutants with defective expression or nuclear localization. We isolated three mutants; smc-5(wsh31), smc-5(wsh32), smc-5(wsh33), that display impaired NSE-1::GFP SNP mapping whole-genome sequencing revealed novel smc-5 alleles: two truncations, alleles smc-5(wsh31) (C587*) smc-5(wsh32) (Q655*), one missense variant, smc-5(wsh33) (Y975D), each altering highly conserved residue domain. All exhibited significantly reduced brood size, progeny viability, slightly elevated male percentages. Phenotypic characterization truncations completely abrogate localization, whereas allele causes stage-dependent, partial mislocalization. Functional assays demonstrated allele-specific developmental stage-dependent hypersensitivities DNA-damaging agents (MMS, HU, cisplatin). These separation-of-function underscore importance domains residues integrity maintenance, provide powerful tools dissect functions vivo.
Language: Английский
Citations
0
Viruses, Journal Year: 2024, Volume and Issue: 16(11), P. 1667 - 1667
Published: Oct. 25, 2024
Cells have developed various mechanisms to counteract viral infections. In an evolutionary arms race, cells mobilize cellular restriction factors fight off viruses, targeted by facilitate their own replication. The hepatitis B virus (HBV) is a small dsDNA that causes acute and chronic infections of the liver. Its genome persists in nuclei infected hepatocytes as covalently closed circular DNA (cccDNA) minichromosome, thus building up episomal persistence reservoir. chromosomal maintenance complex SMC5/6 acts factor hindering cccDNA transcription, whereas regulatory protein HBx targets for proteasomal degradation, relieving transcriptional suppression HBV minichromosome. To date, no curative therapies are available carriers. Knowledge regulating development involving silencing minichromosome or specifically interfering with HBx-SMC5/6 axis holds promise achieving sustained control. Here, we summarize current knowledge mechanism SMC5/6-mediated restriction. We also give overview functions how this compares other viruses. further discuss therapeutic potential investigational drugs axis.
Language: Английский
Citations
3
bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown
Published: Sept. 15, 2024
Chromosomal linkages formed through crossover recombination are essential for accurate segregation of homologous chromosomes during meiosis
Language: Английский
Citations
1
bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown
Published: Nov. 15, 2024
Abstract Centromeres and pericentromeres are specialized chromatin regions whose organization is critical for proper chromosome segregation through dynamic microtubule attachment. Smc5/6, highly enriched in pericentromeres, associates with microtubules. However, whether Smc5/6 contributes to folding dynamics these remains unclear. Here, we dissect function at budding yeast centromeres by constructing smc5-2KE, a separation-of-function mutant that reduces binding replacing two lysines (K624 K631) the Smc5 hinge glutamic acid. After demonstrating reduced smc5-2KE vitro , use high temporal resolution imaging living cells polymer modeling show restricts along arms, thus contributing pericentromeric folding. The shows strong pericentromere-specific reduction homologous recombination repair, as well defects mitotic spindle length, centromere clustering cytokinesis. Overall, our results reveal Smc5/6-microtubule association ensures robust folding, genome integrity face of forces.
Language: Английский
Citations
1
bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown
Published: Nov. 15, 2024
ABSTRACT Fluoroquinolones induce double-strand breaks in bacterial DNA, triggering the SOS response, a major DNA damage response that ensures expression of repair proteins but also promotes emergence and spread antibiotic resistance. Fluoroquinolone resistance, particularly Escherichia coli , is growing global health concern. Understanding responses to these antibiotics critical for developing preventive strategies novel treatments combat resistance development. This study investigates morphology E. following exposure ciprofloxacin, fluoroquinolone antibiotic. We show ciprofloxacin induces stepwise reorganization, culminating highly dense nucleoid structure at midcell — process we term supercompaction. Live cell imaging revealed RecN, structural maintenance chromosomes (SMC)-like protein, required supercompaction, RecN’s dynamics activity this depend on RecA. Additionally, RecN RecA frequently colocalized nucleoid-associated positions. suggest play active roles supercompaction severe damage, their interplay part prompt universal survival coli, extent compaction depends number breaks. GRAPHICAL
Language: Английский
Citations
1
bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown
Published: July 30, 2024
ABSTRACT The Structural Maintenance of Chromosomes (SMC) complexes play roles in cohesion, condensation, replication, transcription, and DNA repair. Their cores are composed SMC proteins with a unique structure consisting an ATPase head, long arm, hinge. direct interaction hinges leads to the formation heterodimer. A critical SMC6 mutation G551R interrupting SMC5 have been previously identified Schizosaccharomyces pombe within conserved motif. Using CRISPR/Cas9 directed oligonucleotide replacement, we introduced this G R point Physcomitrium patens ( P. ) at position 514 also 517 same hinge domain. It turned out that both mutations not toxic do affect viability established Ppsmc6_G514R Ppsmc6_G517R lines. Since mutants entire or partial deletion gene viable, compare mutant line attenuated transcription by targeted binding deactivated Cas9 nuclease Ppsmc6_dCas ). We show fully prevents only SMC5, but NSE5 NSE6. Surprisingly, close residue has no effect all. aberrant morphology quite similar , though absence protonemata branching gametophores is incomplete. On contrary, morphologically more less WT. Spontaneous bleomycin-induced mutagenesis maintenance number rDNA copies while mimics sensitivity bleomycin as severe surprisingly, even sensitive than Moreover, on rate DSB repair dividing differentiated cells. most feature interference targeting (GT). Whilst GT efficiency when compared WT slightly moderately reduced, it completely abolished . Based these results, conclude sufficient amounts its interactions necessary for normal moss development genome stability, such maintenance. reduced levels subunit, therefore low complete SMC5/6 complex, insufficient acute repair, however, affected impaired In contrast, inability interact other partners like NSE6 results GT, mild effect. These data underline importance different aspects SMC5/6, interactions.
Language: Английский
Citations
0
Methods in molecular biology, Journal Year: 2024, Volume and Issue: unknown, P. 11 - 22
Published: Sept. 16, 2024
Language: Английский
Citations
0