RcLS2F - A Novel Fungal Class 1 KDAC Co-repressor Complex in Aspergillus nidulans

Area of Science:

• Molecular Biology
• Mycology
• Biochemistry

Background:

• Class 1 lysine deacetylases (KDACs), like RpdA in *Aspergillus nidulans*, are essential for fungal survival and form multimeric complexes.
• The composition of these RpdA-containing complexes in fungi remained largely unknown.
• RpdA is a potential therapeutic target for invasive fungal infections caused by pathogens like *Aspergillus fumigatus*.

Purpose of the Study:

• To characterize the composition of RpdA-containing protein complexes in *Aspergillus nidulans*.
• To identify novel interactors and functional roles of RpdA complexes.

Main Methods:

• Tandem affinity purification was employed to isolate and identify RpdA-associated proteins.
• Co-immunoprecipitation and genetic analyses were used to confirm protein interactions and functional dependencies.

Main Results:

• A novel RpdA-containing complex, termed RcLS2F, was identified.
• RcLS2F comprises ScrC and the uncharacterized protein FscA, with FscA recruitment dependent on ScrC.
• Loss of the RcLS2F complex explains the suppression of *crzA* deletion phenotypes by ScrC depletion, indicating a role in transcriptional repression.
• RcLS2F is essential for fungal sexual development and participates in an autoregulatory feedback loop.

Conclusions:

• The novel RcLS2F complex plays a critical role in regulating gene expression and is essential for sexual development in *Aspergillus nidulans*.
• Understanding RpdA complex composition provides insights into fungal biology and potential antifungal strategies.
• The findings elucidate a mechanism for transcriptional repression involving RcLS2F and its interaction with the transcription factor CrzA.