PUBLICATION

TFAP2 paralogs facilitate chromatin access for MITF at pigmentation and cell proliferation genes

Authors
Kenny, C., Dilshat, R., Seberg, H.E., Van Otterloo, E., Bonde, G., Helverson, A., Franke, C.M., Steingrímsson, E., Cornell, R.A.
ID
ZDB-PUB-220518-5
Date
2022
Source
PLoS Genetics   18: e1010207 (Journal)
Registered Authors
Bonde, Greg, Cornell, Robert, Kenny, Colin
Keywords
none
Datasets
GEO:GSE198791
MeSH Terms
  • Animals
  • Cell Proliferation/genetics
  • Chromatin/genetics
  • Chromatin/metabolism
  • Gene Expression Regulation, Developmental
  • Melanocytes/metabolism
  • Melanoma*/genetics
  • Melanoma*/metabolism
  • Microphthalmia-Associated Transcription Factor/genetics
  • Microphthalmia-Associated Transcription Factor/metabolism
  • Microphthalmos*/genetics
  • Pigmentation/genetics
  • Zebrafish/genetics
  • Zebrafish/metabolism
PubMed
35580127 Full text @ PLoS Genet.
Abstract
In developing melanocytes and in melanoma cells, multiple paralogs of the Activating-enhancer-binding Protein 2 family of transcription factors (TFAP2) contribute to expression of genes encoding pigmentation regulators, but their interaction with Microphthalmia transcription factor (MITF), a master regulator of these cells, is unclear. Supporting the model that Tfap2 facilitates MITF's ability to activate expression of pigmentation genes, single-cell seq analysis of zebrafish embryos revealed that pigmentation genes are only expressed in the subset of mitfa-expressing cells that also express Tfap2 paralogs. To test this model in SK-MEL-28 melanoma cells we deleted the two TFAP2 paralogs with highest expression, TFAP2A and TFAP2C, creating TFAP2 knockout (TFAP2-KO) cells. We then assessed gene expression, chromatin accessibility, binding of TFAP2A and of MITF, and the chromatin marks H3K27Ac and H3K27Me3 which are characteristic of active enhancers and silenced chromatin, respectively. Integrated analyses of these datasets indicate TFAP2 paralogs directly activate enhancers near genes enriched for roles in pigmentation and proliferation, and directly repress enhancers near genes enriched for roles in cell adhesion. Consistently, compared to WT cells, TFAP2-KO cells proliferate less and adhere to one another more. TFAP2 paralogs and MITF co-operatively activate a subset of enhancers, with the latter necessary for MITF binding and chromatin accessibility. By contrast, TFAP2 paralogs and MITF do not appear to co-operatively inhibit enhancers. These studies reveal a mechanism by which TFAP2 profoundly influences the set of genes activated by MITF, and thereby the phenotype of pigment cells and melanoma cells.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping