ATF7IP-mediated stabilization of the histone methyltransferase SETDB1 is essential for heterochromatin formation by the HUSH complex
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE86814 | GEO | 2016/10/11
SECONDARY ACCESSION(S): PRJNA342607
REPOSITORIES: GEO
Similar Datasets
Project description:The histone methyltransferase SETDB1 plays a central role in repressive chromatin processes, but the functional requirement for its binding partner ATF7IP has remained enigmatic. Here, we show that ATF7IP is essential for SETDB1 stability: nuclear SETDB1 protein is degraded by the proteasome upon ablation of ATF7IP. As a result, ATF7IP is critical for repression that requires H3K9 trimethylation by SETDB1, including transgene silencing by the HUSH complex. Furthermore, we show that loss of ATF7IP phenocopies loss of SETDB1 in genome-wide assays. ATF7IP and SETDB1 knockout cells exhibit near-identical defects in the global deposition of H3K9me3, which results in similar dysregulation of the transcriptome. Overall, these data identify a critical functional role for ATF7IP in heterochromatin formation by regulating SETDB1 abundance in the nucleus.
| S-EPMC5081395 | biostudies-literature
Project description:ATF7IP-mediated stabilization of the histone methyltransferase SETDB1 is essential for heterochromatin formation by the HUSH complex
| PRJNA342607 | ENA
Project description:Non-small cell lung cancer (NSCLC) is one of leading causes of cancer-related mortality worldwide, which harbors various accumulated genetic and epigenetic abnormalities. Histone methyltransferase SETDB1 is a pivotal epigenetic regulator whose focal amplification and upregulation are commonly detected in NSCLC. However, molecular mechanisms underlying the pro-oncogenic function of SETDB1 remain poorly characterized. Here, we demonstrate that SETDB1 augments the migration and invasion capabilities of NSCLC cells by reinforcing invadopodia formation and mediated ECM degradation. At the molecular level, SETDB1 suppresses the expression of FOXA2, a crucial tumor and metastasis suppressor via coordinated epigenetic mechanisms - SETDB1 not only catalyzes histone H3K9 methylation on FOXA2 genomic locus, but also recruits DNMT3A to regulate DNA methylation on CpG island. Consequently, depletion of Setdb1 in murine lung adenocarcinoma cells completely abolished their full and spontaneous metastatic capabilities in mouse xenograft models. These findings together establish the pro-metastasis activity of SETDB1 in NSCLC and elucidate the underlying cellular and molecular mechanisms.
| S-EPMC9801494 | biostudies-literature
Project description:Bone loss caused by mechanical unloading is a threat to prolonged space flight and human health. Epigenetic modifications play a crucial role in varied biological processes, but the mechanism of histone modification on unloading-induced bone loss has rarely been studied. Here, we discovered for the first time that the methyltransferase Setdb1 was downregulated under the mechanical unloading both in vitro and in vivo so as to attenuate osteoblast proliferation. Furthermore, we found these interesting processes depended on the repression of Macrod2 expression triggered by Setdb1 catalyzing the formation of H3K9me3 in the promoter region. Mechanically, we revealed that Macrod2 was upregulated under mechanical unloading and suppressed osteoblast proliferation through the GSK-3β/β-catenin signaling pathway. Moreover, Atf7ip cooperatively contributed to osteoblast proliferation by changing the localization of Setdb1 under mechanical loading. In summary, this research elucidated the role of the Atf7ip/Setdb1/Macrod2 axis in osteoblast proliferation under mechanical unloading for the first time, which can be a potential protective strategy against unloading-induced bone loss.
| S-EPMC9406310 | biostudies-literature
Project description:Dot1 is an evolutionarily conserved histone methyltransferase specific for lysine 79 of histone H3 (H3K79). In Saccharomyces cerevisiae, Dot1-mediated H3K79 methylation is associated with telomere silencing, meiotic checkpoint control, and DNA damage response. The biological function of H3K79 methylation in mammals, however, remains poorly understood. Using gene targeting, we generated mice deficient for Dot1L, the murine Dot1 homologue. Dot1L-deficient embryos show multiple developmental abnormalities, including growth impairment, angiogenesis defects in the yolk sac, and cardiac dilation, and die between 9.5 and 10.5 days post coitum. To gain insights into the cellular function of Dot1L, we derived embryonic stem (ES) cells from Dot1L mutant blastocysts. Dot1L-deficient ES cells show global loss of H3K79 methylation as well as reduced levels of heterochromatic marks (H3K9 di-methylation and H4K20 tri-methylation) at centromeres and telomeres. These changes are accompanied by aneuploidy, telomere elongation, and proliferation defects. Taken together, these results indicate that Dot1L and H3K79 methylation play important roles in heterochromatin formation and in embryonic development.
| S-EPMC2527135 | biostudies-literature
Project description:Understanding of the appropriate regulation of enzymatic activities of histone-modifying enzymes remains poor. The lysine methyltransferase, SETDB1, is one of the enzymes responsible for the methylation of histone H3 at lysine 9 (H3K9) and plays a key role in H3K9 trimethylation-mediated silencing of genes and retrotransposons. Here, we reported that how SETDB1's enzymatic activities can be regulated by the nuclear protein, ATF7IP, a known binding partner of SETDB1. Mechanistically, ATF7IP mediates SETDB1 retention inside the nucleus, presumably by inhibiting its nuclear export by binding to the N-terminal region of SETDB1, which harbors the nuclear export signal motifs, and also by promoting its nuclear import. The nuclear localization of SETDB1 increases its ubiquitinated, enzymatically more active form. Our results provided an insight as to how ATF7IP can regulate the histone methyltransferase activity of SETDB1 accompanied by its nuclear translocation.
| S-EPMC6893292 | biostudies-literature
Project description:Ubiquitination typically occurs through the sequential action of three enzymes catalyzing ubiquitin activation (E1), conjugation (E2), and ligation (E3) and regulates diverse eukaryotic cellular processes. Although monoubiquitination commonly confers nondegradative activities, mechanisms underlying its temporal and spatial regulation and functional plasticity still remain largely unknown. Here we demonstrate that SETDB1, a major histone H3K9 methyltransferase is monoubiquitinated at the evolutionarily conserved lysine-867 in its SET-Insertion domain. This ubiquitination is directly catalyzed by UBE2E family of E2 enzymes in an E3-independent manner while the conjugated-ubiquitin (Ub) is protected from active deubiquitination. The resulting constitutive lysine-867 monoubiquitination is essential for SETDB1's enzymatic activity and endogenous retrovirus silencing in murine embryonic stem cells. Furthermore, the canonical hydrophobic patch on the conjugated-Ub is critical for Ub protection and function. Together, our findings highlight an E3-independent mechanism for monoubiquitination and reveal mechanistic details of SETDB1's enzymatic activity and the functional significance of its SET-Insertion.
| S-EPMC5346476 | biostudies-literature
Project description:A novel histone methyltransferase, termed Set9, was isolated from human cells. Set9 contains a SET domain, but lacks the pre- and post-SET domains. Set9 methylates specifically lysine 4 (K4) of histone H3 (H3-K4) and potentiates transcription activation. The histone H3 tail interacts specifically with the histone deacetylase NuRD complex. Methylation of histone H3-K4 by Set9 precludes the association of NuRD with the H3 tail. Moreover, methylation of H3-K4 impairs Suv39h1-mediated methylation at K9 of H3 (H3-K9). The interplay between the Set9 and Suv39h1 histone methyltransferases is specific, as the methylation of H3-K9 by the histone methyltransferase G9a was not affected by Set9 methylation of H3-K4. Our studies suggest that Set9-mediated methylation of H3-K4 functions in transcription activation by competing with histone deacetylases and by precluding H3-K9 methylation by Suv39h1. Our results suggest that the methylation of histone tails can have distinct effects on transcription, depending on its chromosomal location, the combination of posttranslational modifications, and the enzyme (or protein complex) involved in the particular modification.
| S-EPMC155346 | biostudies-literature
Project description:Understanding of the appropriate regulation of enzymatic activities of histone-modifying enzymes remains poor. The lysine methyltransferase, SETDB1, is one of the enzymes responsible for the methylation of histone H3 at lysine 9 (H3K9) and plays a key role in H3K9 trimethylation-mediated silencing of genes and retrotransposons. Here, we reported that how SETDB1's enzymatic activities can be regulated by the nuclear protein, ATF7IP, a known binding partner of SETDB1. Mechanistically, ATF7IP mediates SETDB1 retention inside the nucleus, presumably by inhibiting its nuclear export by binding to the N-terminal region of SETDB1, which harbors the nuclear export signal motifs, and also by promoting its nuclear import. The nuclear localization of SETDB1 increases its ubiquitinated, enzymatically more active form. Our results provided an insight as to how ATF7IP can regulate the histone methyltranferase activity of SETDB1 accompanied by its nuclear translocation.
| S-SCDT-EMBOR-2019-48297V1 | biostudies-other
Project description:BACKGROUND:The histone methyltransferase SETDB1 (also known as ESET) represses genes and various types of transposable elements, such as endogenous retroviruses (ERVs) and integrated exogenous retroviruses, through a deposition of trimethylation on lysine 9 of histone H3 (H3K9me3) in mouse embryonic stem cells (mESCs). ATF7IP (also known as MCAF1 or AM), a binding partner of SETDB1, regulates the nuclear localization and enzymatic activities of SETDB1 and plays a crucial role in SETDB1-mediated transcriptional silencing. In this study, we further dissected the ATF7IP function with its truncated mutants in Atf7ip knockout (KO) mESCs. RESULTS:We demonstrated that the SETDB1-interaction region within ATF7IP is essential for ATF7IP-dependent SETDB1 nuclear localization and silencing of both ERVs and integrated retroviral transgenes, whereas its C-terminal fibronectin type-III (FNIII) domain is dispensable for both these functions; rather, it has a role in efficient silencing mediated by the SETDB1 complex. Proteomic analysis identified a number of FNIII domain-interacting proteins, some of which have a consensus binding motif. We showed that one of the FNIII domain-binding proteins, ZMYM2, was involved in the efficient silencing of a transgene by ATF7IP. RNA-seq analysis of Atf7ip KO and WT or the FNIII domain mutant of ATF7IP-rescued Atf7ip KO mESCs showed that the FNIII domain mutant re-silenced most de-repressed SETDB1/ATF7IP-targeted ERVs compared to the WT. However, the silencing activity of the FNIII domain mutant was weaker than that of the ATF7IP WT, and some of the de-repressed germ cell-related genes in Atf7ip KO mESCs were not silenced by the FNIII domain mutant. Such germ cell-related genes are targeted and silenced by the MAX/MGA complex, and MGA was also identified as another potential binding molecule of the ATF7IP FNIII domain in the proteomic analysis. This suggests that the FNIII domain of ATF7IP acts as a binding hub of ATF7IP-interacting molecules possessing a specific interacting motif we named FAM and contributes to one layer of the SETDB1/ATF7IP complex-mediated silencing mechanisms. CONCLUSIONS:Our findings contributed to further understanding the function of ATF7IP in the SETDB1 complex, revealed the role of the FNIII domain of ATF7IP in transcriptional silencing, and suggested a potential underlying molecular mechanism for it.
| S-EPMC7706265 | biostudies-literature