Phospho-SIM and exon8b of PML protein regulate formation of doxorubicin-induced rDNA-PML compartment

Hornofova, Terezie; Pokorna, Barbora; Hubáčková, Soňa; Uvizl, Alena; Kosla, Jan; Bártek, Jiří; Hodný, Zdeněk; Vašicová, Pavla

doi:10.1016/j.dnarep.2022.103319

“…After analyzing these and our previous data (36,37), we argued that persistent (r)DNA damage is likely responsible for prolonged RNAPI inhibition, leading to the PNAs formation. To verify this assumption, we examined whether modifying DNA repair pathways could impact the development of PNAs caused by doxorubicin.…”

Section: Induction Of Pnas Is Impacted By the Inhibition Of Specific ...mentioning

confidence: 83%

“…When the stress is relieved, and RNAPI resumes activity, a PML funnel transforms into PML-NDS, a distinct compartment placed next to the non-segregated (i.e., reactivated) nucleolus. PML-NDSs contain nucleolar material, rDNA, and markers of DNA DSBs (36,37). Recently, we found that PML exon 8b and the SUMO-interacting motif (SIM) are the only domains responsible for the recognition of the nucleolar cap and that this association is tightly regulated by p14 ARF -p53 and CK2 (37).…”

Section: Introductionmentioning

confidence: 99%

“…PML-NDSs contain nucleolar material, rDNA, and markers of DNA DSBs (36,37). Recently, we found that PML exon 8b and the SUMO-interacting motif (SIM) are the only domains responsible for the recognition of the nucleolar cap and that this association is tightly regulated by p14 ARF -p53 and CK2 (37). Notably, exon 8b is unique for the PML IV isoform that plays the primary role in the clustering of damaged telomeres (16).…”

Section: Introductionmentioning

confidence: 99%

“…Notably, exon 8b is unique for the PML IV isoform that plays the primary role in the clustering of damaged telomeres (16). Interestingly, PML determinants regulating the interaction with the nucleolus (nucleolar cap) are dispensable for the interaction of PML with persistent DNA DSBs after ionizing radiation (IR) (37), pointing again to the fine regulation of this interaction.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Topological stress triggers persistent DNA lesions in ribosomal DNA with ensuing formation of PML-nucleolar compartment

Urbancokova,

Hornofova,

Novak

et al. 2023

Preprint

Self Cite

0

View full text Add to dashboard Cite

PML, a multifunctional protein, plays a crucial role in forming PML nuclear bodies, which are involved in various cellular processes, including stress responses. Under specific conditions, PML associates with nucleoli, forming PML nucleolar associations (PNAs). However, the stimuli leading to PNAs formation are unknown. Here we investigated these stimuli by exposure of cells to various genotoxic stresses. We reveal that the most potent inducers of PNAs share the ability to inhibit topoisomerases and RNA polymerase I. The inhibition of DNA double-strand break (DSB) repair augmented the occurrence of PNAs linking the stimulus for PNAs formation to unresolved DNA damage. The most potent treatment, doxorubicin, introduced DSBs into the rDNA locus. PNAs co-localized with damaged rDNA, sequestering it from active nucleoli. Using rDNA locus cleavage by I-PpoI, we proved that rDNA damage is a potent PNAs-inducing stimulus. Blocking homology-directed DSB repair (HDR), but not non-homologous end-joining (NHEJ) enhanced PNAs formation, identifying HDR as a PNAs modulator. Our findings have implications for genome stability and diverse diseases and indicate that PNAs form when difficult-to-repair rDNA DSBs occur in nucleoli, highlighting the interplay between the PML/PNAs and rDNA alteration caused by deficiencies in topoisomerases, inhibition of RNAPI, and rDNA DSBs destined for HDR.

show abstract

“…Thus, it is not surprising that biological processes regulated by PML NBs reflect the functions of the PML NB-associated proteins. PML NBs have been shown to be involved in numerous cellular processes, including protein modifications, especially protein SUMOylation [ 19 ]; gene expression and epigenetic regulation [ 31 , 32 ]; the DNA damage response [ 33 , 34 , 35 , 36 ]; apoptosis [ 37 ]; cellular senescence [ 38 ]; and antiviral responses [ 39 ]. Additionally, PML NBs have been linked to the regulation of nuclear protein availability by serving as storage depots for proteins.…”

Section: The Pml Nuclear Body and Its Functionsmentioning

confidence: 99%

Regulating the p53 Tumor Suppressor Network at PML Biomolecular Condensates

Liebl

¹

,

Hofmann

²

2022

Cancers

View full text Add to dashboard Cite

By forming specific functional entities, nuclear biomolecular condensates play an important function in guiding biological processes. PML biomolecular condensates, also known as PML nuclear bodies (NBs), are macro-molecular sub-nuclear organelles involved in central biological processes, including anti-viral response and cell fate control upon genotoxic stress. PML condensate formation is stimulated upon cellular stress, and relies on protein–protein interactions establishing a PML protein meshwork capable of recruiting the tumor suppressor p53, along with numerous modifiers of p53, thus balancing p53 posttranslational modifications and activity. This stress-regulated process appears to be controlled by liquid–liquid phase separation (LLPS), which may facilitate regulated protein-unmixing of p53 and its regulators into PML nuclear condensates. In this review, we summarize and discuss the molecular mechanisms underlying PML nuclear condensate formation, and how these impact the biological function of p53 in driving the cell death and senescence responses. In addition, by using an in silico approach, we identify 299 proteins which share PML and p53 as binding partners, thus representing novel candidate proteins controlling p53 function and cell fate decision-making at the level of PML nuclear biocondensates.

show abstract

Topological stress triggers persistent DNA lesions in ribosomal DNA with ensuing formation of PML-nucleolar compartment

Urbancokova,

Hornofova,

Novak

et al. 2024

eLife

0

View full text Add to dashboard Cite

PML, a multifunctional protein, plays a crucial role in forming PML nuclear bodies, which are involved in various cellular processes, including stress responses. Under specific conditions, PML associates with nucleoli, forming PML nucleolar associations (PNAs). However, the stimuli leading to PNAs formation are unknown. Here we investigated these stimuli by exposure of cells to various genotoxic stresses. We reveal that the most potent inducers of PNAs share the ability to inhibit topoisomerases and RNA polymerase I. The inhibition of DNA double-strand break (DSB) repair augmented the occurrence of PNAs linking the stimulus for PNAs formation to unresolved DNA damage. The most potent treatment, doxorubicin, introduced DSBs into the rDNA locus. PNAs co-localized with damaged rDNA, sequestering it from active nucleoli. Using rDNA locus cleavage by I-PpoI, we proved that rDNA damage is a potent PNAs-inducing stimulus. Blocking homology-directed DSB repair (HDR), but not non-homologous end-joining (NHEJ) enhanced PNAs formation, identifying HDR as a PNAs modulator. Our findings have implications for genome stability and diverse diseases and indicate that PNAs form when difficult-to-repair rDNA DSBs occur in nucleoli, highlighting the interplay between the PML/PNAs and rDNA alteration caused by deficiencies in topoisomerases, inhibition of RNAPI, and rDNA DSBs destined for HDR.

show abstract

Phospho-SIM and exon8b of PML protein regulate formation of doxorubicin-induced rDNA-PML compartment

Cited by 6 publications

References 129 publications

Topological stress triggers persistent DNA lesions in ribosomal DNA with ensuing formation of PML-nucleolar compartment

Topological stress triggers persistent DNA lesions in ribosomal DNA with ensuing formation of PML-nucleolar compartment

Regulating the p53 Tumor Suppressor Network at PML Biomolecular Condensates

Topological stress triggers persistent DNA lesions in ribosomal DNA with ensuing formation of PML-nucleolar compartment

Contact Info

Product

Resources

About