SIX1 (Avr3), Fusarium oxysporum f. sp. lycopersici (Q709D8): curation notes

Sources used

• UniProt Q709D8 (TrEMBL, unreviewed): 284 aa, SignalP 1-21, PDB 7T69 (22-284), 4 disulfides. GO rows in UniProt all come from PHI-base.
• Deep research: SIX1-deep-research-falcon.md. Used for orientation; claims checked against cached papers.
• Cached papers: PMID:15387816 (abstract only), 15672814 (abstract only), 25740416 (abstract only, no PMC), 18464895, 23596453, 26177154, 19851506, 38411527 (full text). PMID:29786161 abstract only.
• New PMIDs verified with PubMed MCP (metadata/citation lookup): 15387816, 29786161, 19851506, 38411527.

Biology

• Found in xylem sap: PMID:15387816
• I-3 avirulence: PMID:15387816
• Virulence plus avirulence: PMID:15672814
• Recognition can be separated from virulence: PMID:29786161
• I-3 is an SRLK: PMID:25740416
• Avr1 suppresses I-3; Avr3 needed for full virulence: PMID:18464895
• Expressed only in planta, depends on Sge1: PMID:19851506
• Structure, FOLD family: PMID:38411527
• No known molecular activity or host target.

Annotation decisions

• GO:0140404 perturbation of host innate immune response (EXP x4): ACCEPT for 15672814, 18464895 and 25740416. The neutral parent fits: recognition activates I-3 immunity, but HR has not been shown (so not GO:0080185) and Six1 has no shown suppressive activity. REMOVE for 26177154: the full text has no SIX1 experiment (I-7 paper; Avr3 appears only in a strain description and the discussion).
• GO:0043657 host cell (EXP, PMID:23596453): REMOVE. Full text checked: SIX1 appears only as a pAVR3:GFP reporter in which PMID:23596453. The host-cell location in that paper is for Avr2.
• GO:0020002 host cell plasma membrane (IDA, PMID:25740416): UNDECIDED. Abstract-only, no PMC copy. Possibly I-3 localisation was mis-attributed, but I could not verify this.
• NEW GO:0140593 host apoplast (IDA, PMID:15387816). Its definition includes the xylem vessel lumen. Comparator: AVR9 (FULFL) uses the same term.
• No NEW process terms. There is no generic pathogen-side "virulence" term, and the virulence mechanism is unknown.

Project curation question 1

All effector process rows use the symbiont-side term GO:0140404 and are experimental (PHI-base), not IEA. However, 2 of 6 PHI-base rows cite papers that do not test SIX1 (PMID:23596453, 26177154). They appear to have been attached by co-mention.