scholarly journals Regulation of the Dot1 histone H3K79 methyltransferase by histone H4K16 acetylation

Science ◽  
2021 ◽  
Vol 371 (6527) ◽  
pp. eabc6663
Author(s):  
Marco Igor Valencia-Sánchez ◽  
Pablo De Ioannes ◽  
Miao Wang ◽  
David M. Truong ◽  
Rachel Lee ◽  
...  

Dot1 (disruptor of telomeric silencing-1), the histone H3 lysine 79 (H3K79) methyltransferase, is conserved throughout evolution, and its deregulation is found in human leukemias. Here, we provide evidence that acetylation of histone H4 allosterically stimulates yeast Dot1 in a manner distinct from but coordinating with histone H2B ubiquitination (H2BUb). We further demonstrate that this stimulatory effect is specific to acetylation of lysine 16 (H4K16ac), a modification central to chromatin structure. We provide a mechanism of this histone cross-talk and show that H4K16ac and H2BUb play crucial roles in H3K79 di- and trimethylation in vitro and in vivo. These data reveal mechanisms that control H3K79 methylation and demonstrate how H4K16ac, H3K79me, and H2BUb function together to regulate gene transcription and gene silencing to ensure optimal maintenance and propagation of an epigenetic state.

2017 ◽  
Author(s):  
Joo-Young Kang ◽  
Ji-Young Kim ◽  
Kee-Beom Kim ◽  
Jin Woo Park ◽  
Hana Cho ◽  
...  

AbstractThe methylation of histone H3 lysine 79 (H3K79) is an active chromatin marker and is prominant in actively transcribed regions of the genome. However, demethylase of H3K79 remains unknown despite intensive research. Here, we show that KDM2B (also known as FBXL10), a member of the Jumonji C family of proteins and known for its histone H3K36 demethylase activity, is a di- and tri-methyl H3K79 demethylase. We demonstrate that KDM2B induces transcriptional repression of HOXA7 and MEIS1 via occupancy of promoters and demethylation of H3K79. Furthermore, genome-wide analysis suggests that H3K79 methylation levels increase when KDM2B is depleted, indicating that KDM2B functions as an H3K79 demethylase in vivo. Finally, stable KDM2B-knockdown cell lines exhibit displacement of NAD+-dependent deacetylase SIRT1 from chromatin, with concomitant increases in H3K79 methylation and H4K16 acetylation. Our findings identify KDM2B as an H3K79 demethylase and link its function to transcriptional repression via SIRT1-mediated chromatin silencing.


2001 ◽  
Vol 21 (23) ◽  
pp. 7913-7922 ◽  
Author(s):  
Matthew C. Lorincz ◽  
Dirk Schübeler ◽  
Mark Groudine

ABSTRACT The majority of 5-methylcytosine in mammalian DNA resides in endogenous transposable elements and is associated with the transcriptional silencing of these parasitic elements. Methylation also plays an important role in the silencing of exogenous retroviruses. One of the difficulties inherent in the study of proviral silencing is that the sites in which proviruses randomly integrate influence the probability of de novo methylation and expression. In order to compare methylated and unmethylated proviruses at the same genomic site, we used a recombinase-based targeting approach to introduce an in vitro methylated or unmethylated Moloney murine leukemia-based provirus in MEL cells. The methylated and unmethylated states are maintained in vivo, with the exception of the initially methylated proviral enhancer, which becomes demethylated in vivo. Although the enhancer is unmethylated and remodeled, the methylated provirus is transcriptionally silent. To further analyze the repressed state, histone acetylation status was determined by chromatin immunoprecipitation (ChIP) analyses, which revealed that localized histone H3 but not histone H4 hyperacetylation is inversely correlated with proviral methylation density. Since members of the methyl-CpG binding domain (MBD) family of proteins recruit histone deacetylase activity, these proteins may play a role in proviral repression. Interestingly, only MBD3 and MeCP2 are expressed in MEL cells. ChIPs with antibodies specific for these proteins revealed that only MeCP2 associates with the provirus in a methylation-dependent manner. Taken together, our results suggest that MeCP2 recruitment to a methylated provirus is sufficient for transcriptional silencing, despite the presence of a remodeled enhancer.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii19-ii19
Author(s):  
Anca Mihalas ◽  
Heather Feldman ◽  
Anoop Patel ◽  
Patrick Paddison

Abstract Current standard of care therapy for glioblastoma (GBM) includes cytoreduction followed by ablative therapies that target rapidly dividing cell types. However, the presence of quiescent-like/G0 states, therefore, represents a natural reservoir of tumor cells that are resistant to current treatments. Quiescence or G0 phase is a reversible state of “stasis” cells enter in response to developmental or environmental cues. To gain insight into how glioblastoma cells might regulate G0-like states, we performed a genome-wide CRISPR-Cas9 screen in patient-derived GBM stem-like cells (GSCs) harboring a G0-reporter to identify genes that when inhibited trap GSCs in G0-like states. Among the top screen hits were members of the Tip60/KAT5 histone acetyltransferase complex, which targets both histones (e.g., H4) and non-histone proteins for acetylation. NuA4 functions as a transcriptional activator, whose activities are coordinated with MYC in certain contexts, and also participates in DNA double-strand break repair by facilitating chromatin opening. However, currently little is known about the roles for NuA4 complex in GBM biology. Through modeling KAT5 function in GSC in vitro cultures and in vivo tumors, we find that KAT5 inhibition causes cells to arrest in a G0-like state with high p27 levels, G1-phase DNA content, low protein synthesis rates, low rRNA rates, lower metabolic rate, suppression of cell cycle gene expression, and low histone H4 acetylation. Interestingly, partial inhibition of KAT5 activity slows highly aggressive tumor growth, while increasing p27hi H4-aclow populations. Remarkably, we that low grade gliomas have significantly higher H4-aclow subpopulations and generally lower H4-ac levels than aggressive grade IV tumors. Taken together, our results suggest that NuA4/KAT5 activity may play a key role in quiescence ingress/egress in glioma and that targeting its activity in high grade tumors may effectively “down grade” them, thus, increase patient survival.


2012 ◽  
Vol 303 (10) ◽  
pp. F1443-F1453 ◽  
Author(s):  
Chung-Hsi Hsing ◽  
Chiou-Feng Lin ◽  
Edmund So ◽  
Ding-Ping Sun ◽  
Tai-Chi Chen ◽  
...  

Bone morphogenetic protein (BMP)-7 protects sepsis-induced acute kidney injury (AKI). Dexmedetomidine (DEX), an α2-adrenoceptor (α2-AR) agonist, has anti-inflammatory effects. We investigated the protective effects of DEX on sepsis-induced AKI and the expression of BMP-7 and histone deacetylases (HDACs). In vitro , the effects of DEX or trichostatin A (TSA, an HDAC inhibitor) on TNF-α, monocyte chemotactic protein (MCP-1), BMP-7, and HDAC mRNA expression in LPS-stimulated rat renal tubular epithelial NRK52E cells, was determined using real-time PCR. In vivo, mice were intraperitoneally injected with DEX (25 μg/kg) or saline immediately and 12 h after cecal ligation and puncture (CLP) surgery. Twenty-four hours after CLP, we examined kidney injury and renal TNF-α, MCP-1, BMP-7, and HDAC expression. Survival was monitored for 120 h. LPS increased HDAC2, HDAC5, TNF-α, and MCP-1 expression, but decreased BMP-7 expression in NRK52E cells. DEX treatment decreased the HDAC2, HDAC5, TNF-α, and MCP-1 expression, but increased BMP-7 and acetyl histone H3 expression, whose effects were blocked by yohimbine, an α2-AR antagonist. With DEX treatment, the LPS-induced TNF-α expression and cell death were attenuated in scRNAi-NRK52E but not BMP-7 RNAi-NRK52E cells. In CLP mice, DEX treatment increased survival and attenuated AKI. The expression of HDAC2, HDAC5, TNF-α, and MCP-1 mRNA in the kidneys of CLP mice was increased, but BMP-7 was decreased. However, DEX treatment reduced those changes. DEX reduces sepsis-induced AKI by decreasing TNF-α and MCP-1 and increasing BMP-7, which is associated with decreasing HDAC2 and HDAC5, as well as increasing acetyl histone H3.


2012 ◽  
Vol 442 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Gráinne Barkess ◽  
Yuri Postnikov ◽  
Chrisanne D. Campos ◽  
Shivam Mishra ◽  
Gokula Mohan ◽  
...  

HMGNs are nucleosome-binding proteins that alter the pattern of histone modifications and modulate the binding of linker histones to chromatin. The HMGN3 family member exists as two splice forms, HMGN3a which is full-length and HMGN3b which lacks the C-terminal RD (regulatory domain). In the present study, we have used the Glyt1 (glycine transporter 1) gene as a model system to investigate where HMGN proteins are bound across the locus in vivo, and to study how the two HMGN3 splice variants affect histone modifications and gene expression. We demonstrate that HMGN1, HMGN2, HMGN3a and HMGN3b are bound across the Glyt1 gene locus and surrounding regions, and are not enriched more highly at the promoter or putative enhancer. We conclude that the peaks of H3K4me3 (trimethylated Lys4 of histone H3) and H3K9ac (acetylated Lys9 of histone H3) at the active Glyt1a promoter do not play a major role in recruiting HMGN proteins. HMGN3a/b binding leads to increased H3K14 (Lys14 of histone H3) acetylation and stimulates Glyt1a expression, but does not alter the levels of H3K4me3 or H3K9ac enrichment. Acetylation assays show that HMGN3a stimulates the ability of PCAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] to acetylate nucleosomal H3 in vitro, whereas HMGN3b does not. We propose a model where HMGN3a/b-stimulated H3K14 acetylation across the bodies of large genes such as Glyt1 can lead to more efficient transcription elongation and increased mRNA production.


1991 ◽  
Vol 11 (2) ◽  
pp. 1048-1061
Author(s):  
I J Lee ◽  
L Tung ◽  
D A Bumcrot ◽  
E S Weinberg

A protein, denoted UHF-1, was found to bind upstream of the transcriptional start site of both the early and late H4 (EH4 and LH4) histone genes of the sea urchin Strongylocentrotus purpuratus. A nuclear extract from hatching blastulae contained proteins that bind to EH4 and LH4 promoter fragments in a band shift assay and produced sharp DNase I footprints upstream of the EH4 gene (from -133 to -106) and the LH4 gene (from -94 to -66). DNase I footprinting performed in the presence of EH4 and LH4 promoter competitor DNAs indicated that UHF-1 binds more strongly to the EH4 site. A sequence match of 11 of 13 nucleotides was found within the two footprinted regions: [sequence: see text]. Methylation interference and footprinting experiments showed that UHF-1 bound to the two sites somewhat differently. DNA-protein UV cross-linking studies indicated that UHF-1 has an electrophoretic mobility on sodium dodecyl sulfate-acrylamide gels of approximately 85 kDa and suggested that additional proteins, specific to each promoter, bind to each site. In vitro and in vivo assays were used to demonstrate that the UHF-1-binding site is essential for maximal transcription of the H4 genes. Deletion of the EH4 footprinted region resulted in a 3-fold decrease in transcription in a nuclear extract and a 2.6-fold decrease in expression in morulae from templates that had been injected into eggs. In the latter case, deletion of the binding site did not grossly disrupt the temporal program of expression from the injected EH4 genes. LH4 templates containing a 10-bp deletion in the consensus region or base substitutions in the footprinted region were transcribed at 14 to 58% of the level of the wild-type LH4 template. UHF-1 is therefore essential for maximal expression of the early and late H4 genes.


2017 ◽  
Vol 114 (38) ◽  
pp. 10101-10106 ◽  
Author(s):  
Kanishk Jain ◽  
Cyrus Y. Jin ◽  
Steven G. Clarke

Arginine methylation on histones is a central player in epigenetics and in gene activation and repression. Protein arginine methyltransferase (PRMT) activity has been implicated in stem cell pluripotency, cancer metastasis, and tumorigenesis. The expression of one of the nine mammalian PRMTs, PRMT5, affects the levels of symmetric dimethylarginine (SDMA) at Arg-3 on histone H4, leading to the repression of genes which are related to disease progression in lymphoma and leukemia. Another PRMT, PRMT7, also affects SDMA levels at the same site despite its unique monomethylating activity and the lack of any evidence for PRMT7-catalyzed histone H4 Arg-3 methylation. We present evidence that PRMT7-mediated monomethylation of histone H4 Arg-17 regulates PRMT5 activity at Arg-3 in the same protein. We analyzed the kinetics of PRMT5 over a wide range of substrate concentrations. Significantly, we discovered that PRMT5 displays positive cooperativity in vitro, suggesting that this enzyme may be allosterically regulated in vivo as well. Most interestingly, monomethylation at Arg-17 in histone H4 not only raised the general activity of PRMT5 with this substrate, but also ameliorated the low activity of PRMT5 at low substrate concentrations. These kinetic studies suggest a biochemical explanation for the interplay between PRMT5- and PRMT7-mediated methylation of the same substrate at different residues and also suggest a general model for regulation of PRMTs. Elucidating the exact relationship between these two enzymes when they methylate two distinct sites of the same substrate may aid in developing therapeutics aimed at reducing PRMT5/7 activity in cancer and other diseases.


2011 ◽  
Vol 18 (5) ◽  
pp. 243-252 ◽  
Author(s):  
Federica Franciosi ◽  
Valentina Lodde ◽  
Ghylène Goudet ◽  
Guy Duchamp ◽  
Stefan Deleuze ◽  
...  

2019 ◽  
Vol 5 (2) ◽  
pp. eaav5590 ◽  
Author(s):  
Giovanni Nassa ◽  
Annamaria Salvati ◽  
Roberta Tarallo ◽  
Valerio Gigantino ◽  
Elena Alexandrova ◽  
...  

Breast cancer (BC) resistance to endocrine therapy results from constitutively active or aberrant estrogen receptor α (ERα) signaling, and ways to block ERα pathway in these tumors are sought after. We identified the H3K79 methyltransferase DOT1L as a novel cofactor of ERα in BC cell chromatin, where the two proteins colocalize to regulate estrogen target gene transcription. DOT1L blockade reduces proliferation of hormone-responsive BC cells in vivo and in vitro, consequent to cell cycle arrest and apoptotic cell death, with widespread effects on ER-dependent gene transcription, including ERα and FOXA1 gene silencing. Antiestrogen-resistant BC cells respond to DOT1L inhibition also in mouse xenografts, with reduction in ERα levels, H3K79 methylation, and tumor growth. These results indicate that DOT1L is an exploitable epigenetic target for treatment of endocrine therapy–resistant ERα-positive BCs.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Yao Liang ◽  
Yuanyuan Su ◽  
Chenzhong Xu ◽  
Na Zhang ◽  
Doudou Liu ◽  
...  

Abstract The histone acetyltransferase (HAT) KAT7/HBO1/MYST2 plays a crucial role in the pre-replication complex (pre-RC) formation, DNA replication and cell proliferation via acetylation of histone H4 and H3. In a search for protein kinase D1 (PKD1)-interacting proteins, we have identified KAT7 as a potential PKD1 substrate. We show that PKD1 directly interacts and phosphorylates KAT7 at Thr97 and Thr331 in vitro and in vivo. PKD1-mediated phosphorylation of KAT7 enhances its expression levels and stability by reducing its ubiquitination-mediated degradation. Significantly, the phospho-defective mutant KAT7-Thr97/331A attenuates histone H4 acetylation levels, MCM2/6 loading on the chromatin, DNA replication and cell proliferation. Similarly, PKD1 knockdown decreases, whereas the constitutive active mutant PKD1-CA increases histone H4 acetylation levels and MCM2/6 loading on the chromatin. Overall, these results suggest that PKD1-mediated phosphorylation of KAT7 may be required for pre-RC formation and DNA replication.


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