The S‐Phase Arrest of Host Cells Caused by an Alpha‐Herpesvirus Genome Replication Facilitates Viral Recruitment of RNA Polymerase II to Transcribe Viral Genes

Cell Proliferation, Год журнала: 2025, Номер unknown

Опубликована: Янв. 27, 2025

ABSTRACT Herpesviruses rely on host RNA polymerae II (RNA Pol II) for their mRNA transcription, yet the mechanisms of which has been poorly defined, while certain herpesviruses can enhance viral gene transcription by altering location, modulating its phosphorylation, or directly interacting with II. However, influence extends beyond these direct effects. Here, we present a novel mechanism cell cycle regulates via during infection Anatid Herpesvirus 1 (AnHV‐1), an avian alpha‐herpesvirus. The results demonstrated that formation replication compartments (vRCs) and subsequent recruitment pol are positively correlated AnHV‐1 DNA synthesis. As progresses, cells arrested in S phase, not only halts but also facilitates transcription. This arrest phase promotes (vDNA) synthesis vRC formation, further enhances preferential to promoters, enabling efficient We propose this hijacking represent offering unique survival strategy compared known herpesviruses. These findings expand our understanding herpesvirus–host interactions highlight potential targets antiviral strategies.

Язык: Английский

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Distinct allosteric networks in CDK4 and CDK6 in the cell cycle and in drug resistance

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Март 4, 2025

Abstract Cyclin-dependent kinases 4 and 6 (CDK4 CDK6) are key regulators of the G1-S phase transition in cell cycle. In cancer cells, CDK6 overexpression often outcompetes CDK4 driving cycle progression, contributing to resistance against CDK4/6 inhibitors (CDK4/6i). This suggests distinct functional conformational differences between these two kinases, despite their striking structural sequence similarities. Understanding mechanisms that differentiate is crucial, as CDK4/6i—frequently linked overexpression—remains a significant therapeutic challenge. Notably, upregulated CDK4/6i-resistant cancers rapidly proliferating hematopoietic stem underscoring its unique regulatory roles. We hypothesize dynamics explain phosphorylation retinoblastoma protein, Rb, inhibitor efficacy, control. leads us question how dissimilar encode actions . To elucidate differential activities, molecular mechanisms, binding, we combine biochemical assays (MD) simulations. discover have allosteric networks connecting β3-αC loop G-loop. exhibits stronger coupling shorter path lengths regions, resulting higher kinase activity upon cyclin binding impacting specificity. also an unrecognized role unstructured C-terminus, which allosterically connects stabilizes R-spine, facilitating slightly activity. Our findings bridge gap similarity divergence CDK6, advancing understanding regulation biology. Graphical abstract

Язык: Английский

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Distinct allosteric networks in CDK4 and CDK6 in the cell cycle and in drug resistance

Journal of Molecular Biology, Год журнала: 2025, Номер unknown, С. 169121 - 169121

Опубликована: Март 1, 2025

Язык: Английский

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The microprotein Nrs1 rewires the G1/S transcriptional machinery during nitrogen limitation in budding yeast

PLoS Biology, Год журнала: 2022, Номер 20(3), С. e3001548 - e3001548

Опубликована: Март 3, 2022

Commitment to cell division at the end of G1 phase, termed Start in budding yeast Saccharomyces cerevisiae , is strongly influenced by nutrient availability. To identify new dominant activators that might operate under different conditions, we screened a genome-wide ORF overexpression library for genes bypass arrest caused absence cyclin Cln3 and transcriptional activator Bck2. We recovered hypothetical gene YLR053c renamed NRS1 Nitrogen-Responsive regulator 1, which encodes poorly characterized 108 amino acid microprotein. Endogenous Nrs1 was nuclear-localized, restricted poor nitrogen induced upon TORC1 inhibition, cycle-regulated with peak Start. interacted genetically SWI4 SWI6 encode subunits main G1/S transcription factor complex SBF. Correspondingly, physically Swi4 Swi6 localized promoter DNA. exhibited inherent transactivation activity, fusion SBF inhibitor Whi5 sufficient suppress other defects. appears be recently evolved microprotein rewires machinery conditions.

Язык: Английский

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When yeast cells change their mind: cell cycle “Start” is reversible under starvation

The EMBO Journal, Год журнала: 2022, Номер 42(2)

Опубликована: Ноя. 23, 2022

Abstract Eukaryotic cells decide in late G1 phase of the cell cycle whether to commit another round division. This point commitment is termed “Restriction Point” mammals and “Start” budding yeast Saccharomyces cerevisiae . At Start, integrate multiple signals such as pheromones nutrients, will not pass Start if nutrients are lacking. However, how respond nutrient depletion after decision remains poorly understood. Here, we analyze post‐Start depletion, by monitoring Whi5, inhibitor whose export from nucleus determines Start. Surprisingly, find that have passed can re ‐import Whi5 into nucleus. In these cells, positive feedback loop activating G1/S transcription interrupted, repressor re‐binds DNA. Cells which re‐import become again sensitive mating pheromone, like pre‐Start CDK activation occur a second time upon replenishment nutrients. These results demonstrate starvation, at be reversed. We therefore propose multi‐step process, similar what has been suggested for mammalian cells.

Язык: Английский

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Evidence for novel mechanisms that control cell-cycle entry and cell size

Molecular Biology of the Cell, Год журнала: 2024, Номер 35(4)

Опубликована: Янв. 17, 2024

Entry into the cell cycle in late G1 phase occurs only when sufficient growth has occurred. In budding yeast, a cyclin called Cln3 is thought to link cell-cycle entry growth. accumulates during early and eventually helps trigger expression of cyclins that drive entry. All current models for assume initiated at transcriptional level. Current also sole function promote transcription cyclins, works solely phase. Here, we show cycle−dependent Cln2 does not require any functions CLN2 promoter. Moreover, can influence accumulation protein via posttranscriptional mechanisms. Finally, mitosis strongly size. Together, these discoveries reveal existence surprising new mechanisms challenge control

Язык: Английский

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Whi5 hypo- and hyper-phosphorylation dynamics control cell-cycle entry and progression

Current Biology, Год журнала: 2024, Номер 34(11), С. 2434 - 2447.e5

Опубликована: Май 14, 2024

Язык: Английский

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Knockdown of PIK3R6 impedes the onset and advancement of clear cell renal cell carcinoma

Cell Adhesion & Migration, Год журнала: 2024, Номер 18(1), С. 1 - 12

Опубликована: Июнь 3, 2024

In this research, we investigated the role of PIK3R6, a regulatory subunit PI3Kγ, known for its tumor-promoting properties, in clear cell renal carcinoma (CCRCC). Utilizing UALCAN website, found PIK3R6 upregulated CCRCC, correlating with lower survival rates. We compared expression CCRCC tumor tissues and adjacent normal using immunohistochemistry. Post RNA interference-induced knockdown 786-O ACHN lines, performed CCK-8, colony formation, Edu staining, flow cytometry, wound healing, transwell assays. Results showed that silencing reduced proliferation, migration, invasion, induced G0/G1 phase arrest apoptosis. Molecular analysis revealed decreased CDK4, Cyclin D1, N-cadherin, Vimentin, Bcl-2, p-PI3K p-AKT, increased cleaved caspase-3, Bax, E-cadherin levels cells. Moreover, inhibiting hindered growth. These findings suggest significant proliferation metastasis, presenting it as potential therapeutic target.

Язык: Английский

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Functional characterization of the human Cdk10/Cyclin Q complex

Open Biology, Год журнала: 2022, Номер 12(3)

Опубликована: Март 1, 2022

Cyclin-dependent kinases (CDKs) are key players in cell cycle regulation and transcription. The CDK-family member Cdk10 is important for neural development can act as a tumour suppressor, but the underlying molecular mechanisms largely unknown. Here, we provide an in-depth analysis of substrate specificity function. Using recombinant Cdk10/CycQ protein complexes, characterize RNA pol II CTD, c-MYC RB1 vitro substrates. analogue-sensitive mutant kinase, identify 89 different phosphosites HEK cells originating from 66 proteins. Among these, proteins involved cycle, translation, stress response, growth signalling, well rRNA, mRNA transcriptional regulation, found. Of set pan-selective CDK- Cdk9-specific inhibitors tested, all inhibited at least five times weaker than their proposed target kinases. We also Cdk1 Cdk5 multiple sites, allowing potential cross-talk between these CDKs. With this functional characterization, adopts hybrid position both regulation.

Язык: Английский

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The suppressive efficacy of THZ1 depends on KRAS mutation subtype and is associated with super‐enhancer activity and the PI3K/AKT/mTOR signalling in pancreatic ductal adenocarcinoma: A hypothesis‐generating study

Clinical and Translational Medicine, Год журнала: 2023, Номер 13(12)

Опубликована: Ноя. 30, 2023

Abstract Background Inhibition of CDK7, a potent transcription regulator, may bring new hope for treating pancreatic ductal adenocarcinoma (PDAC), which is featured by large genetic heterogeneity and abundant KRAS mutations. This investigation aimed at exploring the discrepant efficacies THZ1, small‐molecule covalent CDK7 inhibitor, on PDACs with different mutations underlying mechanisms. Methods Associations expression survival were first assessed. Effects THZ1 PDAC then investigated in vitro vivo. Moreover, effects gene phosphorylation RNA polymerase II (RNAPOLII) mutant assessed, effect super‐enhancer activity was evaluated using chromatin immunoprecipitation sequencing. Lastly, binding H3K27ac to PIK3CA PI3K/AKT/mTOR signalling analysed. Results High significantly linked worse within patients carrying KRAS‐G12V mutation but not those KRAS‐G12D mutation. The apoptosis‐inducing markedly stronger than cancer. inhibited growth xenograft tumour mutation, inhibition tumour. In mini‐cell‐derived (CDX) models, suppressed RNAPOLII, this (especially ser5). had more H3K27ac‐binding super‐enhancers, also PDAC. Furthermore, weakened pathway its downstream markers, cells. Conclusions hypothesis‐generating study, might selectively inhibit certain potently compared some other be associated signalling. Our findings offer novel key clues precise management important evidence future targeted trial design. Highlights PDAC‐bearing G12D Suppressive RNAPOLII

Язык: Английский

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