PXD076161-1

PXD076161 is an original dataset announced via ProteomeXchange.

Title	Modification of the transcription factor FOXL2 at serines 101 and 107 disables DNA binding, leads to nucleolar relocalization, and rewires granulosa-cell programs
Description	FOXL2 is a forkhead transcription factor (TF) essential for granulosa-cell identity and function, yet how post-translational modifications tune its activity remains incompletely understood. Here, we show that protein kinase C phosphorylates FOXL2 in vitro. Two of the four phosphorylation sites, notably Ser101 and Ser107, map to the forkhead DNA-recognition helix. Phosphomimetic substitutions (S->D) at these positions (S101D/S107D) abolish binding to a consensus DNA sequence recognized by FOXL2 and luciferase reporter activation, whereas alanine substitutions are rather neutral. In HeLa cells, the S101D mutant and, to a lesser extent, S107A/S107D, relocalizes at least partially to nucleoli and exhibits increased mobility consistent with reduced DNA engagement. This pattern was recapitulated in stably transduced KGN granulosa cells. RNA-seq of such KGN cells revealed that S101D and a C-terminal truncation (ΔC) induce a massive loss-of-function (LOF) relative to wild-type (WT) FOXL2. The LOF affects sets of genes involved in pathways central to granulosa physiology including ECM organization, cell migration/adhesion and MAPK cascades, whereas S101A is largely WT-like. An analysis of the FOXL2 interactome in the transduced cells by mass spectrometry (MS) showed that S101D loses numerous interactions with TFs and chromatin remodelers, and Pol I/III regulators such as UBTF and TFIIIC components, while its gains other partners. By contrast, ΔC retains many of protein-protein contacts of WT from and preferentially loses ribosomal/TFIII interactions. Together, these data support a model in which PKC-dependent phosphorylation within FOXL2 DNA-recognition helix would underlie a rapid, reversible switch: it weakens DNA binding, redirects subnuclear partitioning, and rewires protein-protein interactions, thereby reshaping FOXL2-dependent gene regulation in granulosa cells.
HostingRepository	PRIDE
AnnounceDate	2026-09-07
AnnouncementXML	Submission_2026-09-07_04:21:10.421.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Guillaume CHEVREUX
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: NEWT:9606;
ModificationList	L-cysteine methyl disulfide; monohydroxylated residue; deamidated residue
Instrument	maXis

Revision	Datetime	Status	ChangeLog Entry
0	2026-03-25 13:02:54	ID requested
⏵ 1	2026-09-07 04:21:11	announced

10.1096/fj.202602528r;

Mousseron L, Chousianiti D, Poulat F, Legois B, Veitia RA, Todeschini AL, Modification of the Transcription Factor FOXL2 at Serines 101 and 107 Disables DNA Binding, Leads to Nucleolar Relocalization, and Rewires Granulosa-Cell Programs. FASEB J, 40(15):e72177(2026) [pubmed]

submitter keyword: Interactome, Nucleolus, FOXL2 phosphorylation,protein kinase C, Transcriptome

TODESCHINI Anne Laure
contact affiliation	Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
contact email	anne-laure.todeschini@ijm.fr
lab head
Guillaume CHEVREUX
contact affiliation	Institut Jacques Monod, CNRS UMR7592
contact email	guillaume.chevreux@ijm.fr
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD076161
     1. Label: PRIDE project
     2. Name: Modification of the transcription factor FOXL2 at serines 101 and 107 disables DNA binding, leads to nucleolar relocalization, and rewires granulosa-cell programs