FXYD2 source and context guide

This review covers 25 original human P54710 contexts. The associated evidence archive retains every original object, all 16 atoms in six conjunctive extension groups, actual TSV/native row locators, natural-product sequences and source-specific reading scopes. Current decisions and synthesis are maintained in the review YAML. Genuine repository acquisition produced all 25 native rows and 28 normal source files; eight existing files were reused unchanged and 20 were acquired.

What the principal experiments establish

Human FXYD2b expression with human alpha1/beta1 in Xenopus oocytes supports condition-dependent Na,K-pump regulation, and human alpha1/beta1/FXYD2 cryo-EM structures establish complex membership. In the intracellular-potassium condition, Table 3 of PMID:33231612 reports sodium K0.5 values of 13.8 mM for alpha1/beta1, 19.5 mM with FXYD1 and 18.1 mM with FXYD2; the Discussion states that the differences disappear without intracellular potassium. The shared baseline direction cannot by itself establish loss of the phosphorylation-dependent positive effect measured for the FXYD1 donor. Mouse Fxyd2 knockout renal enzyme also has increased thermal lability (PMID:15755730). These are distinct from sodium-channel regulation and from attributing alpha-subunit ATP hydrolysis, ion binding or gating directly to gamma. The renal magnesium-wasting association does not identify FXYD2 as a magnesium transporter.

The two IBA rows have real root-node placements in PTHR14132: human leaf PTN002493856 descends from PTN000364858, and the current 66-residue target exactly matches the actual family alignment. All literal source identifiers are retained. The channel-specific inference is refined on functional-type grounds after reading donor assays. Positive-export inheritance remains unresolved because the relevant conditional target mechanism is not established; mixed effects do not prove functional loss, and donor count is not an evidential ranking.

Natural products and historical constructs

UniProt documents P54710-1/A (66 residues) and P54710-2/B (64 residues). The latter replaces canonical MTGLSMDG at residues 1–8 with MDRWYL; both products match direct official FASTA. Sequence identity does not establish equivalent expression or function. Native alternative_products declarations are retained as sequence identities; no independently demonstrated functional classes are invented for functional_isoforms. The functional paper's FXYD2b construct and structural accession AAG37906.1 are not silently equated with a current product without a literal construct-sequence join. Historical 58-residue cloning and 66/68-residue genomic descriptions are preserved as historical reports. G41R is a disease variant, not a natural third product. The urinary-exosome paper's old isoform-1/NP_001671 designation is not current-product evidence without the missing peptide sequence.

Selected original access

The table records what was actually read. Successful selected author-posted or publisher-indexed original passages are distinguished from abstracts and failed PDF/XML routes. No claim of complete experimental coverage follows merely from a cache's full-text flag. Nine optional full_text_unavailable fields have been omitted where a native abstract-only cache coexists with externally read original passages; the exact cache flags below and selected-reading limits in this table supply the unambiguous access record.

The five GO_REF assessments identify the actual mapping methods. They do not convert uninspected individual experiments into verified evidence. The two Reactome location sources were read as immutable cached summaries: sodium/potassium exchange and glycoside binding. Their alpha-subunit pharmacological/pathway claims are not assigned wholesale to FXYD2.

Original extension groups

All listed relations and identifiers are original source data. Each row below has one AND group, with no OR alternative. The archive preserves the complete original JSON and a compact index joining each raw context to the actual native row and physical TSV line. The first published forecast and duplicated scientific snapshots remain in the initial Git version. The intermediate parser's annotation_extension text contains the gene-product name, not these relation atoms. All 16 original atoms are restored through the actual raw-to-native joins; the untouched native seed is preserved separately.

Review boundaries

The broad ion-transport-regulation annotation is refined to sign-neutral GO:1903406, regulation of P-type sodium:potassium-exchanging transporter activity. Its official is_a-only ancestry reaches GO:0043269. The single core also names the already accepted sodium-export and potassium-import processes explicitly as regulation within the pump complex, not independent gamma translocation. The four unresolved rows concern ATPase activation, molecular-adaptor activity, proton transport and conditional positive sodium export. The ATPase-activator uncertainty concerns the unread specific pig PMID:18075585 experiment; accessible human and mouse regulation papers have been read. Their donor/source evidence remains intact. Four broad annotations are TOO_GENERAL only because retained sodium export/potassium import or plasma-membrane terms entail them through checked is_a-only paths. No NEW annotation or extra catalytic assertion is introduced. Five short, verified native-cache excerpts now support the core and selected annotation reviews. The original PMID:33231612 Results excerpt concerns apparent intracellular Na affinity with intracellular K; added excerpts anchor rat pump regulation, knockout mouse Na affinity/thermal stability and rat basolateral location. Exact byte offsets, source hashes and claim-specific limits are retained in the archive. External Table 1/Figure 2 details remain linked selected-original observations, not invented cached quotations.

The archive carries the reviewed evidence and the notes retain the dated private proposal and subsequent acquisition record. Validation and final status are reported only after their actual execution.

Genuine source availability

The repository tools produced the UniProt text, 25-row GOA export and untouched 25-row seed. Two natural product declarations match the reviewed official records. PTHR14132 metadata and 37 reviewed members were fetched natively; its two PAINT rows match the original IBD nodes and donor sets. The existing global PAINT cache was reused unchanged. Two bibliography papers and one Reactome dependency were acquired explicitly after the initial fetch omitted them. Cache availability below is distinct from the selected-reading scope above.