biostudies-literatureXu M-YNational Natural Science Foundation of Chinae0040325https://www.ebi.ac.uk/biostudies/studies/S-EPMC12482196biostudies-literatureUnknown10(9)The yeast-to-filament transition is important for dimorphic fungi to adapt to different environmental conditions. Transcriptional activators that activate downstream target genes in response to environmental stimulations are particularly important for the control of this morphological transition. However, only a limited number of key activators of filamentation have been identified. Here, we report YlAaf1 and YlAaf2, a novel pair of SANT domain-containing transcription factors that promote filamentation in the dimorphic yeast <i>Yarrowia lipolytica</i>. We show that both deletion and co-overexpression of Yl<i>AAF1</i> and Yl<i>AAF2</i> affect filamentation substantially. We also show that YlAaf1 and YlAaf2 interact with each other physically, and the bipartite complex has transcriptional amSphereYlAaf1-YlAaf2, a bipartite SANT domain-containing complex of transcriptional activator, promotes filamentous growth in the dimorphic yeast &lt;i&gt;Yarrowia lipolytica&lt;/i&gt;.PMC1248219632070072Gao X-DWang Z-HXu M-YfalseYlAaf1-YlAaf2, a bipartite SANT domain-containing complex of transcriptional activator, promotes filamentous growth in the dimorphic yeast &lt;i&gt;Yarrowia lipolytica&lt;/i&gt;.The yeast-to-filament transition is important for dimorphic fungi to adapt to different environmental conditions. Transcriptional activators that activate downstream target genes in response to environmental stimulations are particularly important for the control of this morphological transition. However, only a limited number of key activators of filamentation have been identified. Here, we report YlAaf1 and YlAaf2, a novel pair of SANT domain-containing transcription factors that promote filamentation in the dimorphic yeast <i>Yarrowia lipolytica</i>. We show that both deletion and co-overexpression of Yl<i>AAF1</i> and Yl<i>AAF2</i> affect filamentation substantially. We also show that YlAaf1 and YlAaf2 interact with each other physically, and the bipartite complex has transcriptional a2025-01-01T00:00:00Z2025 Sep2026-06-03T23:01:24.696Z2026-05-02T03:12:11.098ZS-EPMC124821964082384810.1128/msphere.00403-25