BAF is a cytosolic DNA sensor that leads to exogenous DNA avoiding autophagy

Kobayashi, Shogo; Koujin, Takako; Kojidani, Tomoko; Osakada, Hiroko; Mori, Chie; Hiraoka, Yasushi; Haraguchi, Tokuko

doi:10.1073/pnas.1501235112

Cited by 38 publications

(80 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In animal cells, DNA sensors mediate the early detection of exogenous DNA, such as DNA of invading pathogens and artificially introduced DNA (9)(10)(11). Both in leukocytes and nonprofessional immune cells, these can trigger innate immune responses, such as cytokine production, autophagy, and apoptosis (9).…”

mentioning

confidence: 99%

“…In the cytoplasm, the amount of DNA decreased within a few hours without completely disappearing, suggesting a rapid degradation of a major fraction and the persistence of a minor fraction of the molecules (13). Within a few hours after introducing DNA into the cytoplasm, tubular membranes and Emerin, a protein synthesized in the endoplasmic reticulum (ER) and subsequently predominantly present in the inner nuclear membrane, appear in the cytoplasm (10,11). However, the functional relevance of these observations is not clear.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Asymmetric partitioning of transfected DNA during mammalian cell division

Wang

Denoth-Lippuner

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Foreign DNA molecules and chromosomal fragments are generally eliminated from proliferating cells, but we know little about how mammalian cells prevent their propagation. Here, we show that dividing human and canine cells partition transfected plasmid DNA asymmetrically, preferentially into the daughter cell harboring the young centrosome. Independently of how they entered the cell, most plasmids clustered in the cytoplasm. Unlike polystyrene beads of similar size, these clusters remained relatively immobile and physically associated to endoplasmic reticulum-derived membranes, as revealed by live cell and electron microscopy imaging. At entry of mitosis, most clusters localized near the centrosomes. As the two centrosomes split to assemble the bipolar spindle, predominantly the old centrosome migrated away, biasing the partition of the plasmid cluster toward the young centrosome. Down-regulation of the centrosomal proteins Ninein and adenomatous polyposis coli abolished this bias. Thus, we suggest that DNA clustering, cluster immobilization through association to the endoplasmic reticulum membrane, initial proximity between the cluster and centrosomes, and subsequent differential behavior of the two centrosomes together bias the partition of plasmid DNA during mitosis. This process leads to their progressive elimination from the proliferating population and might apply to any kind of foreign DNA molecule in mammalian cells. Furthermore, the functional difference of the centrosomes might also promote the asymmetric partitioning of other cellular components in other mammalian and possibly stem cells.foreign DNA | asymmetric cell division | centrosome | endoplasmic reticulum | Ninein G enerally, noncentromeric DNA molecules are mitotically instable in eukaryotes. This results in their apparent disappearance from an ever-increasing proportion of the progeny of an affected cell (e.g., 1-3). Endogenous sources of such DNA are recombination byproducts [double minutes, extrachromosomal ribosomal (r)DNA circles (ERCs) and other DNA circles (3-6)] or mitotic defects generating noncentromeric chromosomal fragments and cytoplasmic micronuclei (1, 7). Exogenous sources are DNA of pathogens or DNA, typically plasmids, artificially introduced into cells. For the latter, decades of work established that plasmid-born protein expression is transient, persisting only for a few cell cycles (8). This finding is consistent with plasmid DNA being somehow eliminated through divisions. Thus, some mechanisms seem to prevent the propagation of foreign DNA and extrachromosomal DNA in proliferating eukaryotic cells. However, how this is achieved is unclear.In animal cells, DNA sensors mediate the early detection of exogenous DNA, such as DNA of invading pathogens and artificially introduced DNA (9-11). Both in leukocytes and nonprofessional immune cells, these can trigger innate immune responses, such as cytokine production, autophagy, and apoptosis (9). However, what happens to the DNA molecules themselves over time is unclear. When microi...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Asymmetric partitioning of transfected DNA during mammalian cell division

Wang

Denoth-Lippuner

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Fenestrations have been suggested as the location of NPC assembly on the reforming NE; we next evaluated the roles of nucleoporins in assembling the NPC on fenestrations of the membrane. For this, we used our previously developed method involving polystyrene beads (Kobayashi et al, ,). In this method, polystyrene beads conjugated with anti‐GFP antibody are incorporated into living cells expressing a GFP‐tagged protein of interest; when the beads are exposed to the cytosol, the GFP‐tagged protein of interest accumulates on the bead surface by binding to anti‐GFP antibody.…”

Section: Resultsmentioning

confidence: 99%

“…The Live CLEM method enables us to link the dynamic properties of molecules of interest to cellular ultrastructures. We also developed an experimental method using an artificial bead conjugated with anti‐GFP antibody (Kobayashi et al, ); in this method, anti‐GFP antibody‐conjugated beads were introduced into living cells expressing a GFP‐tagged protein of interest as an effector molecule, enabling observation of cellular events that occur near the effector beads. Using these methods, we examined whether the NPC together with the NE is assembled at effector molecules on the bead surface.…”

Section: Introductionmentioning

confidence: 99%

Roles of Nup133, Nup153 and membrane fenestrations in assembly of the nuclear pore complex at the end of mitosis

et al. 2019

Self Cite

View full text Add to dashboard Cite

Reassembly of the nuclear pore complex (NPC) at the end of mitosis is an important event for eukaryotic nuclear function. In this study, we examined the dynamic behaviors of the endoplasmic reticulum (ER) by “Live CLEM” imaging. In metaphase, numerous fenestrations on the ER membrane were observed around chromosomes. In telophase, these fenestrations became filled at the region attached to chromosomes, whereas they remained open at the region unattached to chromosomes, suggesting that NPC assembly takes place at fenestrations on the membrane. To determine the roles of nucleoporins in postmitotic NPC formation, we used artificial beads conjugated with anti‐GFP antibody, which captures GFP‐fused proteins on the beads when incorporated into cells. Live CLEM imaging of telophase cells containing Nup133‐coated beads or Nup153‐coated beads showed that Nup133 and Nup153, as the sole effector molecules, assembled the NPC‐like structure on the membrane fenestrations. Indirect immunofluorescence staining of the Nup133‐coated beads showed that Nup133 effectively assembled Nup107 and ELYS, whereas minimal assembly of Nup98 and Nup62 was observed; the Nup153‐coated bead effectively assembled Nup98, Nup62 and Pom121, but assembled neither Nup107 nor ELYS. Our results suggest that Nup133 and Nup153 play different roles in assembling the NPC on membrane fenestrations.

show abstract

“…2E and I, *P<0.05, **P<0.01). In addition, cells were treated with bafilomycin α1 (BAF) which could prevent autophagolysosome formation [30]. BAF stimulation caused significant up-regulation of LC3-II and P62/SQSTM1 protein levels in microRNA-155 mimics-transfected cells (Fig.…”

Section: Resultsmentioning

confidence: 99%

Ox-LDL-Induced MicroRNA-155 Promotes Autophagy in Human Endothelial Cells via Repressing the Rheb/ mTOR Pathway

Lv¹,

Yang²,

Guo³

et al. 2017

Cell Physiol Biochem

View full text Add to dashboard Cite

Background/Aims: Autophagy, an evolutionary conserved biological process, is activated in cells to cope with various types of stress. MicroRNAs control several activities related to autophagy. However, the role of autophagy-related microRNAs during atherosclerosis is far from known. MicroRNA-155 was identified to be a crucial regulator of atherosclerosis. The objectives of the study were to analyze the effect of microRNA-155 on autophagic signaling and explore its mechanism in human endothelial cells under ox-LDL stress. Methods: The study included human endothelial cells surrogate EA.hy926 lines (EA.hy926 cells). The expression of microRNA-155 was analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The effect of microRNA-155 on endothelial autophagy was observed along with the expression levels of Rheb, LC3B, Beclin1, and P62/SQSTM1 by western blotting (WB) and immunofluorescence through microRNA-155 overexpression or inhibition. Bioinformatics analysis and Luciferase reporter assay were used to explore the target gene of microRNA-155. Cell viability and apoptosis were examined by 3-[4,5-dimethylthiazol-2-yl]-5- [3-carboxy-methoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium inner salt (MTS) assay and TdT-mediated dUTP Nick-End Labeling (TUNEL) apoptosis assay. Results: MicroRNA-155 expression was significantly increased under ox-LDL stress. MicroRNA-155 increased autophagic activity, while inhibition of it alleviated ox-LDL-induced autophagy in EA.hy926 endothelial cells. In addition, dual-luciferase reporter assays showed that microRNA-155 suppressed Rheb transcription. MicroRNA-155 increased autophagic activity in EA.hy926 cells via inhibition of Rheb-mediated mTOR/P70S6kinase/4EBP signaling pathway. Furthermore, we demonstrated that microRNA-155 could regulate not only autophagy but also apoptosis in EA.hy926 cells. Conclusions: MicroRNA-155 works as a regulator of endothelial function under ox-LDL stress, making it a potential candidate for the novel therapeutic strategies against atherosclerotic diseases.

show abstract

BAF is a cytosolic DNA sensor that leads to exogenous DNA avoiding autophagy

Cited by 38 publications

References 39 publications

Asymmetric partitioning of transfected DNA during mammalian cell division

Asymmetric partitioning of transfected DNA during mammalian cell division

Roles of Nup133, Nup153 and membrane fenestrations in assembly of the nuclear pore complex at the end of mitosis

Ox-LDL-Induced MicroRNA-155 Promotes Autophagy in Human Endothelial Cells via Repressing the Rheb/ mTOR Pathway

Contact Info

Product

Resources

About