Annotation inferences using phylogenetic trees

Phylogenetic (IBA) annotations from GO_Central. GO:0000159 comes from the eukaryote scaffold node PTN000068663 and GO:0019888 from PTN000068596; PTN000068596 also carries a GO:0140378 protein complex scaffold activity IBD (2026-06-03) not yet in the fetched GOA. The BP IBDs at PTN000068664 (spindle assembly; meiotic sister chromatid cohesion, centromeric) are on an animal/fungal subclade and were not propagated to F6LAX4.

Electronic Gene Ontology annotations created by ARBA machine learning models

ARBA rule-based (IEA) annotations assigning nucleus (GO:0005634), cytoplasm (GO:0005737) and protein-containing complex (GO:0032991).

file:WHEAT/F6LAX4/F6LAX4-deep-research-falcon.md

Deep-research report (falcon / Edison Scientific Literature) - functional annotation of wheat PP2A scaffolding A subunit (F6LAX4 / LOC123103357).

No primary literature characterizes this wheat gene; functional annotation is family-level inference grounded in canonical PP2A-A structure-function evidence.
The PP2A A subunit is a HEAT-repeat alpha-solenoid that binds the catalytic C subunit and recruits regulatory B subunits, controlling substrate specificity, localization and activity of PP2A holoenzymes.
Arabidopsis RCN1/PP2AA1 functions in auxin distribution and root development, with redundancy among the three A subunits.

PMID:17174897

Structure of the protein phosphatase 2A holoenzyme.

Crystal structure of the PP2A heterotrimer showing the scaffolding subunit as one of the two subunits of the core enzyme, contacted by both catalytic and B'/B56 subunits.

PMID:22404109

Arabidopsis thaliana histone deacetylase 14 (HDA14) is an α-tubulin deacetylase that associates with PP2A and enriches in the microtubule fraction with the putative histone acetyltransferase ELP3.

Arabidopsis PP2A A subunits A1, A2 and A3 (co-orthologs of F6LAX4) reside in both the nucleus and the cytosol.

file:human/PPP2R1A/PPP2R1A-uniprot.txt

UniProt record P30153 (human PPP2R1A)

Curated function text (with PubMed evidence) describing PR65 as the scaffold that coordinates assembly of the catalytic and variable B subunits.

file:WHEAT/F6LAX4/F6LAX4-uniprot.txt

UniProt record F6LAX4

TrEMBL PE3 entry, 587 aa, with PP2A regulatory subunit A family signatures (IPR051023, PF22646) and HEAT repeats spanning the whole protein.

file:WHEAT/F6LAX4/F6LAX4-bioinformatics/RESULTS-rereview.md

F6LAX4 phylogenetic placement among PP2A scaffold A subunits (re-review)

F6LAX4 is full length and groups with grass A subunits; the three Arabidopsis A subunits are eudicot-specific paralogs, so F6LAX4 is a co-ortholog of all three. The PANTHER SF4 versus SF29/SF36 split between grass and Arabidopsis A subunits is a subfamily-HMM boundary, not a functional divergence.