
Transcription factor Met4 and its co-activator Met32 form liquid-liquid phase separated condensates in yeast nuclei upon methionine depletion. These condensates co-localize with and mediate the 3D clustering of their target genes, leading to enhanced transcriptional activity of the clustered genes.


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Some transcription factors (TFs) can form liquid-liquid phase separated (LLPS) condensates. However, the functions of these TF condensates in 3D genome organization and gene regulation remain elusive. In response to methionine (met) starvation, budding yeast TF Met4 and a few co-activators, including Met32, induce a set of genes involved in met biosynthesis. Here, we show that the endogenous Met4 and Met32 form co-localized puncta-like structures in yeast nuclei upon met depletion. Recombinant Met4 and Met32 form mixed droplets with LLPS properties in vitro . In relation to chromatin, Met4 puncta co-localize with target genes, and at least a subset of these target genes are clustered in 3D in a Met4-dependent manner. A MET3pr -GFP reporter inserted near several native Met4 binding sites becomes co-localized with Met4 puncta and displays enhanced transcriptional activity. A Met4 variant with a partial truncation of an intrinsically disordered region (IDR) shows less puncta formation, and this mutant selectively reduces the reporter activity near Met4 binding sites to the basal level. Overall, these results support a model where Met4 and co-activators form condensates to bring multiple target genes into a vicinity with higher local TF concentrations, which facilitates a strong response to methionine depletion.

### Competing Interest Statement

The authors have declared no competing interest.

Transcription Factor Condensates Mediate Clustering of MET Regulon and Enhancement in Gene Expression

transcription-factor-condensates-mediate-clustering-of-met-regulon-genes-and-enhance-their-gene-expression


Transcription Factor Condensates Mediate Clustering of MET Regulon Genes and Enhance Their Gene Expression
