Cell identity in eukaryotes is controlled by transcriptional regulatory networks that define cell-type-specific gene expression. In the opportunistic fungal pathogen Candida albicans, transcriptional regulatory networks regulate epigenetic switching between two alternative cell states, ‘white’ and ‘opaque’, that exhibit distinct host interactions. In the present study, we reveal that the transcription factors (TFs) regulating cell identity contain prion-like domains (PrLDs) that enable liquid–liquid demixing and the formation of phase-separated condensates. Multiple white–opaque TFs can co-assemble into complex condensates as observed on single DNA molecules. Moreover, heterotypic interactions between PrLDs support the assembly of multifactorial condensates at a synthetic locus within live eukaryotic cells. Mutation of the Wor1 TF revealed that substitution of acidic residues in the PrLD blocked its ability to phase separate and co-recruit other TFs in live cells, as well as its function in C. albicans cell fate determination. Together, these studies reveal that PrLDs support the assembly of TF complexes that control fungal cell identity and highlight parallels with the ‘super-enhancers’ that regulate mammalian cell fate.

真核生物中的细胞身份由定义细胞类型特异性基因表达的转录调控网络控制。在机会性真菌病原体白色念珠菌中，转录调节网络调节表现出不同的宿主相互作用的两种不同细胞状态“白色”和“不透明”之间的表观遗传转换。在本研究中，我们揭示了调节细胞身份的转录因子（TFs）包含病毒样结构域（PrLDs），可进行液-液分离并形成相分离的冷凝物。如在单个DNA分子上观察到的，多个不透明的TF可以共组装成复杂的缩合物。此外，PrLDs之间的异型相互作用支持活真核细胞内合成位点处的多因子缩合物的组装。Wor1 TF的突变表明，PrLD中酸性残基的取代阻止了其在活细胞中相分离和共同招募其他TF的能力，以及其在肝细胞中的功能。白色念珠菌细胞命运的确定。总之，这些研究表明，PrLDs支持TF复合物的组装，该复合物控制真菌细胞的特性，并突出与调节哺乳动物细胞命运的“超级增强剂”的相似之处。