Promyelocytic leukemia nuclear bodies (PM NBs), often referred to as membraneless organelles, are dynamic macromolecular protein complexes composed of a PML protein core and other transient or permanent components. PML NBs have been shown to play a role in a wide variety of cellular processes. This review describes in detail the diverse and complex interactions between small and medium size DNA viruses and PML NBs that have been described to date. The PML NB components that interact with small and medium size DNA viruses include PML protein isoforms, ATRX/Daxx, Sp100, Sp110, HP1, and p53, among others. Interaction between viruses and components of these NBs can result in different outcomes, such as influencing viral genome expression and/or replication or impacting IFN-mediated or apoptotic cell responses to viral infection. We discuss how PML NB components abrogate the ability of adenoviruses or Hepatitis B virus to transcribe and/or replicate their genomes and how papillomaviruses use PML NBs and their components to promote their propagation. Interactions between polyomaviruses and PML NBs that are poorly understood but nevertheless suggest that the NBs can serve as scaffolds for viral replication or assembly are also presented. Furthermore, complex interactions between the HBx protein of hepadnaviruses and several PML NBs-associated proteins are also described. Finally, current but scarce information regarding the interactions of VP3/apoptin of the avian anellovirus with PML NBs is provided. Despite the considerable number of studies that have investigated the functions of the PML NBs in the context of viral infection, gaps in our understanding of the fine interactions between viruses and the very dynamic PML NBs remain. The complexity of the bodies is undoubtedly a great challenge that needs to be further addressed.

• Klíčová slova
• DNA viruses, Daxx, PML, PML nuclear bodies, SUMOylation, Sp100, Sp110,
• MeSH
• Adenoviridae MeSH
• DNA viry * genetika   MeSH
• jaderné proteiny * metabolismus   MeSH
• promyelocytická leukemická tělíska MeSH
• protein promyelocytické leukemie metabolismus   MeSH
• transkripční faktory metabolismus   MeSH
• viry MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• jaderné proteiny * MeSH
• protein promyelocytické leukemie MeSH
• transkripční faktory MeSH

PML, a multifunctional protein, is crucial for forming PML-nuclear bodies involved in stress responses. Under specific conditions, PML associates with nucleolar caps formed after RNA polymerase I (RNAPI) inhibition, leading to PML-nucleolar associations (PNAs). This study investigates PNAs-inducing stimuli by exposing cells to various genotoxic stresses. We found that the most potent inducers of PNAs introduced topological stress and inhibited RNAPI. Doxorubicin, the most effective compound, induced double-strand breaks (DSBs) in the rDNA locus. PNAs co-localized with damaged rDNA, segregating it from active nucleoli. Cleaving the rDNA locus with I-PpoI confirmed rDNA damage as a genuine stimulus for PNAs. Inhibition of ATM, ATR kinases, and RAD51 reduced I-PpoI-induced PNAs, highlighting the importance of ATM/ATR-dependent nucleolar cap formation and homologous recombination (HR) in their triggering. I-PpoI-induced PNAs co-localized with rDNA DSBs positive for RPA32-pS33 but deficient in RAD51, indicating resected DNA unable to complete HR repair. Our findings suggest that PNAs form in response to persistent rDNA damage within the nucleolar cap, highlighting the interplay between PML/PNAs and rDNA alterations due to topological stress, RNAPI inhibition, and rDNA DSBs destined for HR. Cells with persistent PNAs undergo senescence, suggesting PNAs help avoid rDNA instability, with implications for tumorigenesis and aging.

• Klíčová slova
• PML, aberrant DNA topology, cancer biology, cell biology, cellular senescence, genome maintenance, human, persistent rDNA damage,
• MeSH
• buněčné jadérko * metabolismus   MeSH
• dvouřetězcové zlomy DNA MeSH
• lidé MeSH
• poškození DNA MeSH
• protein promyelocytické leukemie * metabolismus   genetika   MeSH
• ribozomální DNA * genetika   metabolismus   MeSH
• RNA-polymerasa I metabolismus   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• PML protein, human MeSH Prohlížeč
• protein promyelocytické leukemie * MeSH
• ribozomální DNA * MeSH
• RNA-polymerasa I MeSH

Repetitive sequences are among the most unstable regions in the eukaryotic genome and defects in their maintenance correlate with premature aging and cancer development. Promyelocytic leukemia protein (PML) induces accumulation of proteins at distinct nuclear sites, thereby affecting a plethora of processes including DNA repair or maintenance of telomeres. Doxorubicin, the broadly used chemotherapeutic compound, induces formation of PML-nucleolar associations (PNAs). Nevertheless, molecular factors affecting formation of PNAs are still largely unknown. Here we show that PNAs can accumulate ribosomal DNA (rDNA) and, after restoration of RNA polymerase I activity, these structures transfer a fraction of rDNA outside the nucleolus. Mutagenesis of PML isoforms revealed that this process depends on the SUMO-interacting motif and adjacent serine-rich region, and is enhanced by exon8b present exclusively in PML IV isoform. Moreover, we demonstrate that PNAs formation is also regulated by p14ARF/p53 tumor suppressors and casein kinase 2. Our data elucidate how PML nucleolar compartment is assembled, bring the first evidence of PML interacting with rDNA, and show the PML-dependent translocation of rDNA away from the nucleolus.

• Klíčová slova
• Nucleolus, P14(ARF), PML, Phospho-SIM, rDNA,
• MeSH
• doxorubicin farmakologie   MeSH
• jaderné proteiny * metabolismus   MeSH
• nádorové supresorové proteiny genetika   metabolismus   MeSH
• peptidové nukleové kyseliny * MeSH
• protein - isoformy metabolismus   MeSH
• ribozomální DNA genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• doxorubicin MeSH
• jaderné proteiny * MeSH
• nádorové supresorové proteiny MeSH
• peptidové nukleové kyseliny * MeSH
• protein - isoformy MeSH
• ribozomální DNA MeSH

The PML protein is concentrated in the PML nuclear bodies. Downregulation of the PML protein has been described in various types of cancer and is in accordance with the fact that dysqualification of tumor suppressive functions of the PML protein might promote cancer development. Various differences have been described between sporadic breast cancer and that associated with BRCA1 and BRCA2 gene mutations. Expression of the PML protein has not been studied yet. The aim of this study was to determine if there is any difference in PML protein expression in breast cancer of BRCA1 and BRCA2 gene mutation carriers compared to sporadic breast cancer and if the PML protein can be used as a prognostic marker. There were 47 breast cancer samples included, 14 and 10 from BRCA1 and BRCA2 germline mutation carriers, respectively, and 23 from patients without a BRCA1/BRCA2 germline mutation. Immunofluorescence staining was used. Downregulation of PML protein expression was found in 2 of 14 (14%), 3 of 10 (30%) and 15 of 47 (31%) cases of breast cancer samples from BRCA1, BRCA2 and no BRCA1/BRCA2 mutation carriers, respectively (p(BRCA1) = 0.019; p(BRCA2) = 0.111). There was no correlation between PML protein expression and age, histological types, estrogen and progesterone receptor, c-erbB-2 and PCNA expression, TNM classification, disease-free and overall survival. In conclusion, the PML protein is downregulated in approximately 30% of breast cancers cases. Downregulation of PML protein expression was significantly less frequent in BRCA1 mutation carriers compared to sporadic cases. No correlation was found between PML protein expression and any of the other clinical and laboratory characteristics.

• MeSH
• buněčné jádro metabolismus   patologie   MeSH
• duktální karcinom prsu genetika   metabolismus   patologie   MeSH
• fluorescenční protilátková technika nepřímá MeSH
• heterozygot MeSH
• jaderné proteiny metabolismus   MeSH
• lidé MeSH
• lobulární karcinom genetika   metabolismus   patologie   MeSH
• mucinózní adenokarcinom genetika   metabolismus   patologie   MeSH
• nádorové proteiny metabolismus   MeSH
• nádorové supresorové proteiny metabolismus   MeSH
• nádory prsu genetika   metabolismus   patologie   MeSH
• protein BRCA1 genetika   MeSH
• protein BRCA2 genetika   MeSH
• protein promyelocytické leukemie MeSH
• receptory pro estrogeny metabolismus   MeSH
• receptory progesteronu metabolismus   MeSH
• transkripční faktory metabolismus   MeSH
• zárodečné mutace genetika   MeSH
• zinkové prsty MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• jaderné proteiny MeSH
• nádorové proteiny MeSH
• nádorové supresorové proteiny MeSH
• PML protein, human MeSH Prohlížeč
• protein BRCA1 MeSH
• protein BRCA2 MeSH
• protein promyelocytické leukemie MeSH
• receptory pro estrogeny MeSH
• receptory progesteronu MeSH
• transkripční faktory MeSH

The bulk of DNA damage caused by ionizing radiation (IR) is generally repaired within hours, yet a subset of DNA lesions may persist even for long periods of time. Such persisting IR-induced foci (pIRIF) co-associate with PML nuclear bodies (PML-NBs) and are among the characteristics of cellular senescence. Here we addressed some fundamental questions concerning the nature and determinants of this co-association, the role of PML-NBs at such sites, and the reason for the persistence of DNA damage in human primary cells. We show that the persistent DNA lesions are devoid of homologous recombination (HR) proteins BRCA1 and Rad51. Our super-resolution microscopy-based analysis showed that PML-NBs are juxtaposed to and partially overlap with the pIRIFs. Notably, depletion of 53BP1 resulted in decreased intersection between PML-NBs and pIRIFs implicating the RNF168-53BP1 pathway in their interaction. To test whether the formation and persistence of IRIFs is PML-dependent and to investigate the role of PML in the context of DNA repair and senescence, we genetically deleted PML in human hTERT-RPE-1 cells. Unexpectedly, upon high-dose IR treatment, cells displayed similar DNA damage signalling, repair dynamics and kinetics of cellular senescence regardless of the presence or absence of PML. In contrast, the PML knock-out cells showed increased sensitivity to low doses of IR and DNA-damaging agents mitomycin C, cisplatin and camptothecin that all cause DNA lesions requiring repair by HR. These results, along with enhanced sensitivity of the PML knock-out cells to DNA-PK and PARP inhibitors implicate PML as a factor contributing to HR-mediated DNA repair.

• Klíčová slova
• Cellular senescence, DNA-PK and PARP/olaparib, Homologous recombination, Ionizing radiation, Super-resolution microscopy,
• MeSH
• 53BP1 metabolismus   MeSH
• genový knockout MeSH
• intranukleární inkluzní tělíska metabolismus   účinky záření   MeSH
• lidé MeSH
• oprava DNA * účinky záření   MeSH
• poškození DNA * MeSH
• protein promyelocytické leukemie nedostatek   genetika   metabolismus   MeSH
• stárnutí buněk genetika   účinky záření   MeSH
• ubikvitinligasy metabolismus   MeSH
• vztah dávky záření a odpovědi MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 53BP1 MeSH
• PML protein, human MeSH Prohlížeč
• protein promyelocytické leukemie MeSH
• RNF168 protein, human MeSH Prohlížeč
• ubikvitinligasy MeSH

The PML (promyelocytic leukemia) protein is concentrated in the PML nuclear bodies. In human cell lines and tumors maintaining their telomeres by alternative lengthening (ALT), the PML protein is colocalized with TRF2 and several other proteins in the so called ALT-associated PML bodies. The aim of this study was to determine if there is any difference in PML protein expression between tumors with stable microsatellites (MSS) and those with high-frequency microsatellite instability (MSI-H), if PML protein expression might be a prognostic factor and if MSI-H tumors more frequently use alternative lengthening of telomeres measured by the presence of ALT-associated PML bodies. Eighty colorectal cancer samples (32 MSI-H and 48 MSS) and 8 human tumor cell lines (Saos-2, U2OS, DU145, LNCaP, U87, HeLa, MCF7 and T98G) were included into the study. Double-colour immunofluorescence staining was used. Downregulation of PML protein expression was found in 7 of 32 (22%) MSI-H and 11 of 48 (23%) MSS tumors (p=0.520). There was no correlation between PML expression and age, histological typing, localization of the tumor in colon, TNM classification, disease-free and overall survival. The Saos-2 and U2OS (ALT using cell lines) and the MCF7 (active telomerase) cell line were characterized by the presence of ALT-associated PML bodies; no such bodies were detected in the DU145, LNCaP, U87, HeLa and T98G cell lines (active telomerase); accumulation of TRF2 was absent or much weaker in these cell lines compared to Saos-2 or U2OS. Accumulation of the TRF2 protein was detected in 16 of 80 (20%) tumors and PML and TRF2 colocalization in 2 MSI-H tumors (6%). In conclusion, the PML protein was downregulated in approximately 20% of tumors; there was no difference between MSS and MSI-H tumors. PML protein expression does not seem to be a prognostic factor.

• MeSH
• adaptorové proteiny signální transdukční genetika   MeSH
• DNA nádorová MeSH
• dospělí MeSH
• homolog 2 proteinu MutS genetika   MeSH
• jaderné proteiny genetika   metabolismus   MeSH
• kolorektální nádory genetika   metabolismus   patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mikrosatelitní nestabilita * MeSH
• mikrosatelitní repetice MeSH
• mucinózní adenokarcinom genetika   metabolismus   patologie   MeSH
• MutL homolog 1 MeSH
• nádorové buňky kultivované MeSH
• nádorové proteiny metabolismus   MeSH
• nádorové supresorové proteiny metabolismus   MeSH
• nádory genetika   metabolismus   patologie   MeSH
• polymerázová řetězová reakce MeSH
• protein promyelocytické leukemie MeSH
• protein TRF2 metabolismus   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• telomerasa metabolismus   MeSH
• telomery fyziologie   MeSH
• transkripční faktory metabolismus   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• DNA nádorová MeSH
• homolog 2 proteinu MutS MeSH
• jaderné proteiny MeSH
• MLH1 protein, human MeSH Prohlížeč
• MSH2 protein, human MeSH Prohlížeč
• MutL homolog 1 MeSH
• nádorové proteiny MeSH
• nádorové supresorové proteiny MeSH
• PML protein, human MeSH Prohlížeč
• protein promyelocytické leukemie MeSH
• protein TRF2 MeSH
• telomerasa MeSH
• TERT protein, human MeSH Prohlížeč
• transkripční faktory MeSH

It is known that nuclear DNA helicase II (NDH II) links CREB-binding protein directly to RNA polymerase II holoenzyme, and that this interaction is essential for gene activation by CREB. Here, we report for the first time that some NDH II/RNA helicase A is a component of promyelocytic leukemia nuclear bodies (PML NBs). An autoimmune serum specific for PML NBs was identified and used in immunoprecipitation experiments. NDH II was present in the immunoprecipitates as shown by mass spectrometry and by immunoblotting. Immunofluorescence and ultrastructural studies showed that NDH II colocalizes with a small subset of PML NBs in control cells, however, colocalizes with practically all bodies in interferon-alpha-stimulated cells. After interferon stimulation, more PML NBs were found to contain newly synthesized RNA, as indicated by bromouridine incorporation. PML NBs also contain RNA polymerase II. The association of NDH II with PML NBs was transcriptionally dependent, and NDH II was present in all bodies with nascent RNA. Blocking of mRNA synthesis caused NDH II relocalization from nucleoplasm to nucleoli. Based on the data, we suggest that NDH II recruitment to PML NBs is connected with transcriptional regulation of interferon-alpha-inducible genes attached to PML NBs.

• MeSH
• adenosintrifosfatasy genetika   metabolismus   MeSH
• amanitiny farmakologie   MeSH
• autoimunitní nemoci imunologie   MeSH
• DNA-helikasy genetika   metabolismus   MeSH
• DNA biosyntéza   genetika   MeSH
• elektronová mikroskopie MeSH
• eukaryotické buňky enzymologie   ultrastruktura   MeSH
• genetická transkripce účinky léků   genetika   MeSH
• HeLa buňky MeSH
• imunohistochemie MeSH
• inhibitory syntézy nukleových kyselin farmakologie   MeSH
• interferon alfa genetika   farmakologie   MeSH
• jaderné proteiny * MeSH
• krevní proteiny imunologie   farmakologie   MeSH
• lidé MeSH
• makromolekulární látky MeSH
• messenger RNA biosyntéza   genetika   MeSH
• nádorové proteiny genetika   metabolismus   MeSH
• nádorové supresorové proteiny MeSH
• precipitinové testy MeSH
• protein promyelocytické leukemie MeSH
• struktury buněčného jádra enzymologie   ultrastruktura   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfatasy MeSH
• amanitiny MeSH
• DNA-helikasy MeSH
• DNA MeSH
• inhibitory syntézy nukleových kyselin MeSH
• interferon alfa MeSH
• jaderné proteiny * MeSH
• krevní proteiny MeSH
• makromolekulární látky MeSH
• messenger RNA MeSH
• nádorové proteiny MeSH
• nádorové supresorové proteiny MeSH
• PML protein, human MeSH Prohlížeč
• protein promyelocytické leukemie MeSH
• transkripční faktory MeSH

Diverse stress insults trigger interactions of PML with nucleolus, however, the function of these PML nucleolar associations (PNAs) remains unclear. Here we show that during induction of DNA damage-induced senescence in human non-cancerous cells, PML accumulates at the nucleolar periphery simultaneously with inactivation of RNA polymerase I (RNAP I) and nucleolar segregation. Using time-lapse and high-resolution microscopy, we followed the genesis, structural transitions and destiny of PNAs to show that: 1) the dynamic structural changes of the PML-nucleolar interaction are tightly associated with inactivation and reactivation of RNAP I-mediated transcription, respectively; 2) the PML-nucleolar compartment develops sequentially under stress and, upon stress termination, it culminates in either of two fates: disappearance or persistence; 3) all PNAs stages can associate with DNA damage markers; 4) the persistent, commonly long-lasting PML multi-protein nucleolar structures (PML-NDS) associate with markers of DNA damage, indicating a role of PNAs in persistent DNA damage response characteristic for senescent cells. Given the emerging evidence implicating PML in homologous recombination-directed DNA repair, we propose that PNAs contribute to sequestration and faithful repair of the highly unstable ribosomal DNA repeats, a fundamental process to maintain a precise balance between DNA repair mechanisms, with implications for genomic integrity and aging.

• Klíčová slova
• DNA damage, nucleolar segregation, rDNA loci, super-resolution microscopy, time-lapse imaging,
• MeSH
• buněčné jadérko metabolismus   MeSH
• doxorubicin MeSH
• fyziologický stres MeSH
• kultivované buňky MeSH
• lidé MeSH
• poškození DNA * MeSH
• protein promyelocytické leukemie metabolismus   MeSH
• stárnutí buněk * MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• doxorubicin MeSH
• PML protein, human MeSH Prohlížeč
• protein promyelocytické leukemie MeSH

In four cases of progressive multifocal leucoencephalitis the basic disease was always a malignant lymphogranuloma. Changes in the brain were multifocal, however the frontoparietal area of the white matter was affected most frequently and foci in this part were oldest. In these foci demyelination with atypical astrogliosis predominated, and there was a very small number of scavenger cells. At the periphery of foci always proliferation and enlargement of homogenous oligodendroglia nuclei were found sometimes with inclusions which in immunoassay sometimes had a common antigen with papovirus SV 40 and on electronoptic examination always contained many virions of the papovirus. No direct relationship was found between the duration of the neoplastic process, its type and changes in the CNS.

• MeSH
• barvení a značení MeSH
• biopsie MeSH
• buněčná inkluze MeSH
• corpus callosum MeSH
• demyelinizační nemoci patologie   MeSH
• dospělí MeSH
• elektronová mikroskopie MeSH
• Hodgkinova nemoc komplikace   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mozek patologie   MeSH
• oligodendroglie patologie   MeSH
• progresivní multifokální leukoencefalopatie etiologie   patologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

Promyelocytic leukemia protein (PML), a tumor suppressor, forms in most human cell types discrete multiprotein complexes termed PML nuclear bodies. Here, we have used indirect immunofluorescence and confocal microscopy to describe various forms of a novel nuclear PML compartment associated with nucleoli that is found under growth-permitting conditions in human mesenchymal stem cells (hMSC) and skin fibroblasts but not in several immortal cell lines with defects in the p53 and pRb pathways. In addition, we found that shut-off of rRNA synthesis induced by actinomycin D causes PML translocation to the surface of segregated nucleoli. This translocation is dynamic and reversible, following changes in nucleolar activity. Intriguingly, treatment causing premature senescence restores PML binding to nucleoli-derived structures and to the surface of segregated nucleoli in HeLa cells. These findings indicate that PML may be involved in nucleolar functions of normal non-transformed or senescent cells. The absence of nucleolar PML compartment in rapidly growing tumor-derived cells suggests that PML association with the nucleolus might be important for cell-cycle regulation.

• MeSH
• buněčné jadérko chemie   ultrastruktura   MeSH
• buněčné linie MeSH
• fibroblasty cytologie   MeSH
• fluorescenční mikroskopie MeSH
• HeLa buňky MeSH
• jaderné proteiny analýza   metabolismus   MeSH
• lidé MeSH
• mezenchymální kmenové buňky cytologie   MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny analýza   metabolismus   MeSH
• nádorové supresorové proteiny analýza   metabolismus   MeSH
• nádory patologie   MeSH
• protein promyelocytické leukemie MeSH
• stárnutí buněk * MeSH
• transkripční faktory analýza   metabolismus   MeSH
• transport proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• jaderné proteiny MeSH
• nádorové proteiny MeSH
• nádorové supresorové proteiny MeSH
• PML protein, human MeSH Prohlížeč
• protein promyelocytické leukemie MeSH
• transkripční faktory MeSH