Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Acetylation reprograms MITF target selectivity and residence time

ABSTRACT: Key to effective gene regulation in development and homeostasis is the ability of transcription factors to discriminate between different classes of binding sites. Yet how this is achieved is poorly understood. The microphthalmia-associated transcription factor MITF is a lineage-survival oncogene that plays a crucial role in melanoma and melanocyte development where it suppresses invasion but promotes both proliferation and differentiation. How MITF distinguishes between differentiation and proliferation-associated targets is unknown. Unexpectedly we show here that differentiation-associated target genes are characterized by low affinity MITF binding sites. MAPK signaling, a key driver of melanomagenesis downstream from BRAF and NRAS, promotes p300/CBP-mediated MITF acetylation at K206 to reduce preferentially DNA binding affinity at differentiation-associated targets. The results reveal a MAPK-driven acetylation switch that can trigger de-differentiation of melanocytes and provide a mechanistic explanation of why a human K206Q MITF mutation is associated with Waardenburg’s syndrome characterized by pigmentation abnormalities.

ORGANISM(S): Homo sapiens

PROVIDER: GSE137776 | GEO | 2023/08/07

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Tuning Transcription Factor Availability through Acetylation-Mediated Genomic Redistribution

Project description:It is widely assumed that decreasing transcription factor DNA-binding affinity reduces transcription initiation by diminishing occupancy of sequence-specific regulatory elements. However in vivo transcription factors find their binding sites while confronted with a large excess of low affinity degenerate motifs. Here we show, using the melanoma lineage survival oncogene MITF as a model, that low affinity binding sites act as a competitive reservoir in vivo from which TFs are released by MAPK-stimulated acetylation to promote increased occupancy of their regulatory elements. Consequently a low DNA-binding affinity acetylation-mimetic MITF mutation supports melanocyte development and drives tumorigenesis, whereas a high affinity, non-acetylatable mutant does neither. The results reveal a paradoxical acetylation-mediated molecular clutch that tunes transcription factor availability via genome-wide titration and couples BRAF to tumorigenesis. Our results further suggest that genomic titration regulated by p300/CBP-mediated acetylation will represent a common mechanism to control TF availability.

2020-06-11 | GSE137522 | GEO

BRAF/MAPK and GSK3 signaling converges to control MITF nuclear export

Project description:The close integration of the MAPK, PI3K, and WNT signaling pathways underpins much of development and is deregulatedin cancer. In principle, combinatorial posttranslational modification of key lineage specific transcription factors would be an effective mean stointegrate critical signaling events. Understanding how this might be achieved is central to deciphering the impact of microenvironmental cues in development and disease. The microphthalmia-associated transcription factor MITF plays a crucial role in the development of melanocytes, the retinal pigment epithelium, osteoclasts, and mast cells and acts as a lineage survival oncogene in melanoma. MITF coordinates survival, differentiation, cell-cycle progression, cell migration, metabolism, and lysosome biogenesis. However, how the activity of this key transcriptionfactoriscontrolledremainspoorlyunderstood.Here,we showthatGSK3,downstreamfromboththePI3KandWntpathways, and BRAF/MAPK signaling converge to control MITF nuclear export. Phosphorylation of the melanocyte MITF-M isoform in response to BRAF/MAPK signaling primes for phosphorylation by GSK3, a kinase inhibited by both PI3K and Wnt signaling. Dual phosphorylation, but not monophosphorylation, then promotes MITF nuclear export by activatinga previously unrecognizedhydrophobic exportsignal. NonmelanocyteMITFisoformsexhibitpoorregulationbyMAPKsignaling, but instead their export is controlled by mTOR. We uncover here an unanticipated mode of MITF regulation that integrates the output of key developmental and cancer-associated signaling pathways to gate MITF flux through the import–export cycle. The results have significant implications for our understanding of melanoma progression and stem cell renewal.

2019-11-12 | PXD010782 | Pride

BRAF/MAPK and GSK3b signalling signaling converge to control MITF nuclear export

Project description:The close integration of the MAPK, PI3K and WNT signaling pathways underpins much of development and is deregulated in cancer. In principle, combinatorial post-translational modification of key lineage–specific transcription factors would be an effective means to integrate critical signaling events. Understanding how this might be achieved is central to deciphering the impact of microenvironmental cues in development and disease. The microphthalmia associated transcription factor, MITF, plays a crucial role in the development of melanocytes, the retinal pigment epithelium, osteoclasts and mast cells, and acts as a lineage survival oncogene in melanoma. MITF coordinates survival, differentiation, cell cycle progression, cell migration, metabolism and lysosome biogenesis. Yet how the activity of this key transcription factor is controlled remains poorly understood. Here we show that GSK3b, downstream from both the PI3K and Wnt pathways, and BRAF/MAPK signaling converge to control MITF nuclear export. Phosphorylation of the melanocyte MITF-M isoform in response to BRAF/MAPK signaling primes for phosphorylation by GSK3b, a kinase inhibited by both PI3K and Wnt signaling. Dual phosphorylation, but not monophosphorylation, then promotes MITF nuclear export by activating a previously unrecognized hydrophobic export signal. Nonmelanocyte MITF isoforms exhibit poor regulation by MAPK signaling, but instead their export is controlled by mTOR. We uncover here an unanticipated mode of MITF regulation that integrates the output of key developmental and cancer-associated signaling pathways to gate MITF flux through the import-export cycle. The results have significant implications for our understanding of melanoma progression and stem cell renewal

2022-02-28 | PXD010665 | Pride

The sMAF transcription factor MAFG is a potent driver of melanoma

Project description:While common mutations in potent proto-oncogenes and tumor suppressors induce melanoma formation, no recurrent mutations associated with the late stages of melanomagenesis have been identified. Instead, non-mutational mechanisms such as the deregulation of transcriptiona or epigenetic programs typically promote the malignant progression and metastasis of melanoma. We have previously identified the small MAFG transcription factor MAFG as a critical target of the melanoma suppressor miRNA miRN-29, prompting an in-depth evaluation of the role of MAFG in melanoma. MAFG expression is elevated in melanoma compared to melanocytes and increases with tumor stage. Ectopic expression of MAFG in human melanocytes and melanoma cells enhances proliferation in virto and promotes melanoma growth in vivo. Moreover, MAFG overexpression in BRAFV600E; PTEN+/- mice accelerated melanomagenesis, significantly shortening overall survival. Despite being a critical NRF2 dimerization partner, NRF2 was dispensable for the effects of MAFG. Moreover, MAFG overexpression in melanoma had no effect on the activity of NRF2 transcriptional reporters, nor did it induce transcriptional programs associated with NRF2. RNA sequencing and pathway analysis revealed MAFG-mediated effects on melanoma-associated processes such as pigmentation. Indeed, MAFG downregulated MITF and its target genes in the pigmentation pathway in melanoma cells. We next analyzed the connection between MAFG and MITF and found that MAFG binds to MITF to impede its binding to melanocytic differentiation genes, thus promoting a less differentiated and more aggressive phenotype. Our study establishes MAFG as a potent driver of melanoma development through the relocation of MITF.

2024-10-09 | GSE274810 | GEO

Acetylation reprograms MITF target selectivity and residence time

Project description:Acetylation reprograms MITF target selectivity and residence time

| PRJNA573049 | ENA

MITF WT and K243-mutant binding and expression [ChIP-Seq]

Project description:MITF is the master regulator of the melanocyte lineage and a melanoma lineage oncogene. It controls a wide range of target genes fulfilling many distinct functions, but relatively little is known about how its DNA-binding is regulated to select the correct target genes. The datasets presented here were used investigate the effects of MAPK signaling-induced MITF-acetylation on MITF activity in melanoma cells through ChIP-Seq of wild-type and acetyl-mutant MITF.

2021-02-12 | GSE77437 | GEO

Targeting the lineage-specific long non-coding RNA LINC01212 as an effective anti-melanoma therapeutic strategy

Project description:Focal amplifications of 3p13-3p14 occur in about 10% of melanoma and are associated with poor prognosis. The melanoma-specific oncogene MITF resides at the epicenter of this amplicon1 . However, whether other loci present in this amplicon also contribute to melanomagenesis is unknown. Here we show that the recently annotated long non-coding RNA gene LINC01212 is consistently cogained with MITF. In addition to being amplified, LINC01212 is a target of the lineage-specific transcription factor SOX10 and, consequently, it is expressed in more than 90% of human melanomas, but not in normal adult tissues. Whereas exogenous LINC01212 functions in trans to increase melanoma clonogenic potential, LINC01212 knock-down drastically decreases the viability of melanoma cells irrespective of their transcriptional cell state, BRAF, NRAS or TP53 status and increases their sensitivity to MAPK-targeting therapeutics both in vitro and in Patient-Derived Xenograft (PDX) models. Mechanistically, LINC01212 interacts with p32, a master regulator of mitochondrial homeostasis and metabolism, to increase its mitochondrial targeting and pro-oncogenic function. Our results indicate that targeting the lineage addiction oncogene LINC01212, especially in combination with BRAFV600Einhibitors, disrupts vital mitochondrial functions in a cancer-cell specific manner and is therefore expected to deliver highly effective and tissuerestricted anti-melanoma therapeutic responses.

2016-01-13 | PXD002565 | Pride

Targeting the lineage-specific long non-coding RNA LINC01212 as an effective anti-melanoma therapeutic strategy [2]

Project description:Focal amplifications of 3p13-3p14 occur in about 10% of melanoma and are associated with poor prognosis. The melanoma-specific oncogene MITF resides at the epicenter of this amplicon1. However, whether other loci present in this amplicon also contribute to melanomagenesis is unknown. Here we show that the recently annotated long non-coding RNA gene LINC01212 is consistently co-gained with MITF. In addition to being amplified, LINC01212 is a target of the lineage-specific transcription factor SOX10 and, consequently, it is expressed in more than 90% of human melanomas, but not in normal adult tissues. Whereas exogenous LINC01212 functions in trans to increase melanoma clonogenic potential LINC01212 knock-down dramatically decreases the viability of melanoma cells irrespective of their transcriptional cell state, BRAF, NRAS or TP53 status, diminishes melanoma growth and increases their sensitivity to MAPK-targeting therapeutics both in vitro and in patient-derived melanoma xenograft mouse models. Mechanistically, LINC01212 functions as a lineage addiction oncogene by interacting with and modulating the cellular localization and function of two proteins, XRN2 and p32, involved in nucleolar and mitochondrial rRNA processing, ribosome biogenesis and protein synthesis. LINC01212 targeting, especially in combination with BRAFV600E-inhibitors, is expected to deliver highly effective and tissue-restricted antimelanoma therapeutic responses. Five GapmeR3 treated and four control treated patient derived xenografts were analysed.

2016-01-15 | E-GEOD-70177 | biostudies-arrayexpress

Feed-forward Cysteine Regulation Maintains Melanoma Differentiation State and Limits Metastatic Spread

Project description:The inherent ability of melanoma cells to alter the differentiation-associated transcriptional repertoire to evade treatment and facilitate metastatic spread is well accepted and has been termed phenotypic switching. However, how these facets of cellular behavior are controlled remains largely elusive. Here we show that cysteine availability, whether from lysosomes (CTNS-dependent) or exogenously derived (SLC7A11-dependent or as N-acetylcysteine), controls melanoma differentiation-associated pathways by acting on the melanocyte master regulator MITF. Functional data indicate that low cysteine availability reduces MITF levels and impairs lysosome functions, which affects tumor ferroptosis sensitivity but improves metastatic spread in vivo. Mechanistically, cysteine-restrictive conditions reduce acetyl-CoA levels to decrease p300-mediated H3K27 acetylation at the melanocyte-restricted MITF promoter, thus forming a cysteine feed-forward regulation that controls MITF levels and downstream lysosome functions. These findings collectively suggest that cysteine homeostasis governs melanoma differentiation by maintaining MITF levels and lysosome functions, which protect against ferroptosis and limit metastatic spread.

2024-08-16 | GSE269922 | GEO

Novel mechanisms of MITF regulation identified in a mouse suppressor screen

Project description:MITF, a basic-Helix-Loop-Helix Zipper (bHLHZip) transcription factor, plays vital roles in melanocyte development and functions as an oncogene. We performed a genetic screen for suppressors of the Mitf-associated pigmentation phenotype in mice and identified an intragenic Mitf mutation that terminates MITF at the K316 SUMOylation site, leading to loss of the C-end intrinsically disordered region (IDR). The resulting protein is more nuclear but less stable than wild-type MITF and retains DNA-binding ability. Interestingly, as a dimer, it can translocate wild-type and mutant MITF partners into the nucleus, improving its own stability thus ensuring nuclear MITF supply. To further understand the effect of the suppressor mutation (MITF-sl), we performed CUT&RUN experiments to determine how MITF-sl affects the genome-wide occupancy of MITF. MITF-sl had a higher number of peaks than MITF-WT, with 10,636 peaks (p<0.01) exhibiting statistically significant differences (p < 0.01) between MITF-WT and MITF-sl. Gene ontology analysis indicates that the peaks significantly different between MITF-WT and MITF-sl are associated with genes involved in axonogenesis, axon development, cell growth, and positive regulation of MAPK cascade biological pathways. Our results suggest that the 316-419 domain is critical for selective genome occupancy and transcriptional activation of MITF.

2024-11-06 | GSE267956 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data