Abstract
Abstract 2379 Gene Dosage and Protein Valency Impact Phase Separation and Fungal Cell Fate
The Journal of biological chemistry, Vol.301(5 Supplement), 109287
05/2025
DOI: 10.1016/j.jbc.2025.109287
Abstract
Cell fate decisions in eukaryotes are regulated by interconnected networks of transcription factors (TFs) that drive heritable changes in cell identity. However, much is still unknown about how TFs act together to alter cell fate, despite links to cellular dysfunction and disease when TF function is aberrant. Here, we addressed the interplay between network TFs that control heritable switching in the diploid fungal pathogen Candida albicans. This species can propagate in two alternative cell states, white and opaque, with epigenetic transitions between states regulated by a core network of eight TFs plus >100 auxiliary TFs. We dissected the role of these TFs using simple and complex haploinsufficiency (CHI) analyses to examine the impact of gene dosage on cell fate. Among single heterozygotes, loss of one WOR1 allele had the greatest impact on white-opaque switching in line with its role as the master regulator of the opaque state, while CHI analysis revealed strong genetic interactions between other core TFs including WOR3 and WOR4. We also modulated TF function by changing interaction valency, a measure of the number of inter-molecular interactions a given protein can undergo. We engineered strains with increased Wor1 valency, via the addition of extra prion-like domains, via constitutive dimerization, or via rapamycin-inducible dimerization. All three methods of increasing Wor1 valency caused increased white-opaque switching frequencies by up to two orders of magnitude. Moreover, increasing the valency of Wor1 and other TFs via forced dimerization increased their propensity to form phase-separated condensates in the nuclei of mammalian cells. Together, these experiments highlight that changes to both TF gene dosage and TF valency can result in striking changes to cell fate determination and link these changes to the propensity of TFs to undergo condensate formation.
Details
- Title: Subtitle
- Abstract 2379 Gene Dosage and Protein Valency Impact Phase Separation and Fungal Cell Fate
- Creators
- Collin Ganser - Brown UniversityPeiling HeCorey FrazerDamian KrysanRichard Bennett
- Resource Type
- Abstract
- Publication Details
- The Journal of biological chemistry, Vol.301(5 Supplement), 109287
- Publisher
- Elsevier Inc
- DOI
- 10.1016/j.jbc.2025.109287
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Grant note
- NIH NIAID: AI081704, AI141893
Funding for this work was from NIH NIAID (AI081704 and AI141893 to Richard J. Bennett) .
- Language
- English
- Date published
- 05/2025
- Academic Unit
- Molecular Physiology and Biophysics; Stead Family Department of Pediatrics; Infectious Disease (Pediatrics)
- Record Identifier
- 9984832082402771
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