AHP1 notes (Q9ZNV9, At3g21510, ATHP3)

2026-10-05 review session (cytokinin two-component signaling module)

• Identity: symbol search for AHP1 also hits AHL10 (O22812, "AT-hook protein 1"); fetched by accession Q9ZNV9 with alias AHP1. Verified AHP1_ARATH, At3g21510, 154 aa.
• Note nomenclature: AHP1 = ATHP3 of Urao/Miyata (PMID:9804162, PMID:10930573).
• Deep research tooling failed; review from cached publications.
• HPt function: PMID:10050311; complements yeast ypd1 PMID:10050311.
• Redundant positive regulator of cytokinin signaling PMID:17122069.
• Localization: originally cytokinin-induced nuclear translocation PMID:11574878, later shown constitutively nucleocytosolic PMID:20484973.
• CKI1-AHP-type-B ARR pathway in female gametophyte PMID:20363773 -> non-core.
• Protein binding: HK partners (AHK2/3/4, ETR1) -> MODIFY to GO:0043424; ARR partners -> REMOVE (no GO term for response-regulator binding; phosphotransfer captured by GO:0009927).