PXD051232

PXD051232 is an original dataset announced via ProteomeXchange.

Title	Auxin Response Factor 6 and 8 LC-MS
Description	The phytohormone auxin plays a pivotal role in promoting fruit initiation and growth upon fertilization in flowering plants. Upregulation of auxin signaling by genetic mutations or exogenous auxin treatment can induce seedless fruit formation from unpollinated ovaries, termed parthenocarpy. Recent studies suggested that the class A AUXIN RESPONSE FACTOR6 (ARF6) and ARF8 play dual functions by first inhibiting fruit initiation when complexed with unidentified corepressor IAA protein(s) before pollination, and later promoting fruit growth after fertilization as ARF dimers. However, whether and how posttranslational modification(s) regulate ARF6- and ARF8-mediated fruit growth were unknown. In this study, we reveal that both ARF6 and ARF8 are O-fucosylated in their middle region (MR) by SPINDLY (SPY), a novel nucleocytoplasmic protein O-fucosyltransferase, which catalyzes the addition of a fucose moiety to specific Ser/Thr residues of target proteins. Epistasis, biochemical and transcriptome analyses indicated that ARF6 and ARF8 are downstream of SPY, but ARF8 plays a more predominant role in parthenocarpic fruit growth. Intriguingly, two ARF6/8 interacting proteins, the co-repressor IAA9 and MED8, a subunit of the coactivator Mediator complex, were also O-fucosylated by SPY. Biochemical assays demonstrated that SPY-mediated O-fucosylation of these proteins reduced ARF-MED8 interaction, which led to enhanced transcription repression activity of the ARF6/8-IAA9 complex but impaired transactivation activities of ARF6/8. Our study unveils the role of protein O-fucosylation by SPY in attenuating auxin-triggered fruit growth through modulation of activities of key transcription factors, co-repressor and the coactivator MED complex.
HostingRepository	PRIDE
AnnounceDate	2025-03-27
AnnouncementXML	Submission_2025-03-27_05:09:57.794.xml
DigitalObjectIdentifier	https://dx.doi.org/10.6019/PXD051232
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Supported dataset by repository
PrimarySubmitter	Seamus Kelley
SpeciesList	scientific name: Arabidopsis thaliana (Mouse-ear cress); NCBI TaxID: 3702; scientific name: Nicotiana benthamiana; NCBI TaxID: 4100;
ModificationList	N-acetylaminoglucosylated residue; fucosylated residue; monohexosylated residue; phosphorylated residue; iodoacetamide derivatized residue
Instrument	Orbitrap Fusion

Revision	Datetime	Status	ChangeLog Entry
0	2024-04-06 09:00:14	ID requested
⏵ 1	2025-03-27 05:09:58	announced

10.6019/PXD051232;

submitter keyword: Arabidopsis,LC-MS, O-GlcNacylation, fucosylation

Dr Jeffrey Shabanowitz
contact affiliation	University of Virginia
contact email	js4c@virginia.edu
lab head
Seamus Kelley
contact affiliation	University of Virginia
contact email	sk6nr@virginia.edu
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD051232
     1. Label: PRIDE project
     2. Name: Auxin Response Factor 6 and 8 LC-MS