EPF2 (At1g34245, Q8LC53) curation notes

Session 2026-10-06 (stomatal_lineage_development module). Falcon deep research (just deep-research-falcon ARATH EPF2) failed with HTTP 402 (provider quota), so no provider deep-research file exists; notes below are from cached primary literature.

Identity

• UniProt Q8LC53 EPF2_ARATH, 120 aa, signal peptide 1-25, mature MEPF2 chain 69-120, four disulfides; plant cysteine-rich secretory peptide family, EPF subfamily.

Key findings

• Produced by MMCs and early lineage cells; limits MMC fate non-cell-autonomously PMID:19435754.
• Loss -> excess small lineage cells; overexpression -> virtually no stomata PMID:19398336.
• Direct ligand of ERECTA (primary) with TMM as modulator PMID:22241782; MEPF2 also binds TMM PMID:22241782.
• Stomagen competes with EPF2 for ER/TMM; EPF2 elicits MPK3/6 phosphorylation within 10 min PMID:26083750.
• Required for CO2 repression of stomatal development; CRSP protease cleaves EPF2 PMID:25043023.

Curation decisions

• Core MF: receptor ligand activity (GO:0048018, IBA accepted). IPI "protein kinase binding" rows MODIFIED to receptor ligand activity (TMM has no kinase domain; ERECTA binding is ectodomain-ligand binding).
• Core BP: negative regulation of stomatal complex development (GO:2000122). Guard cell differentiation (IBA and IMP) MODIFIED to GO:2000122 - EPF2 acts at lineage entry and inhibits; IBA propagation_review records TERM_SCOPING_PROBLEM / regulatory sign.
• No GO-CAM models contain EPF2 (gocams/index.tsv checked).