FRI (FRIGIDA) curation notes

Session 2026-10-05 (vernalization_flc_silencing module)

• Accession choice: the functional protein is P0DH90 (FRIGI_ARATH; H51/Sf-2 allele, 609 aa). The Col-0 entry Q67Z93 (At4g00650, "Inactive protein FRIGIDA", 314 aa) encodes a truncated loss-of-function allele. Folder FRI = P0DH90. GOA rows on P0DH90 are sparse (2 IPI protein binding, 1 IEA nuclear speck).
• Falcon deep research failed (agentapi not found / timeout), so no deep-research file was written.
• Natural variation: PMID:11030654
• FRI up-regulates FLC: PMID:14973192
• FRI-C scaffold: PMID:21282526; SUF4 provides DNA binding: PMID:21282526.
• Chromatin: PMID:19567704
• Cap-binding complex: PMID:19429606. The FIP1/FIP2 Y2H interactors are uninformative: PMID:19429606.
• Localization: PMID:17138694. Cold condensates: PMID:34732891. This paper was the subject of a Matters Arising exchange (reply PMID:37438593), so it is used cautiously.

Decisions

• Protein binding (FIP1, FIP2): REMOVE as uninformative.
• Nuclear speck IEA: ACCEPT.
• NEW: transcription coactivator activity (GO:0003713), positive regulation of DNA-templated transcription (GO:0045893), nucleus (IDA). The coactivator term was chosen over protein-macromolecule adaptor activity because FRI-C is explicitly a transcription activator complex and FRI has no DNA-binding domain.