ATP1A1

Summary: InterPro IPR023299 supports nucleotide binding by the ATP1A1 catalytic machinery.

Reason: InterPro IPR023299 supports nucleotide binding by the ATP1A1 catalytic machinery. ATP is the established nucleotide substrate, independently resolved in the human pump structure. Retain this existing parent-level annotation alongside the separately supplied ATP-binding rows; the core states the specific ATP-driven exchange activity and no new broad assertion is proposed.

Summary: Retain regulation of sodium ion transport as non-core context.

Reason: Retain the curator-transferred rat sodium-transport regulatory context. The principal activity is direct Na/K exchange; the donor-specific regulatory mechanism was not reconstructed and is not made a separate core.

Summary: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump.

Reason: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump. Independent direct human alpha/beta oocyte currents, purified functional complexes and human structures support this existing pump activity. Preserve the original evidence code and species boundary rather than relabeling every source as human IDA.

Summary: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump.

Reason: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump. Independent direct human alpha/beta oocyte currents, purified functional complexes and human structures support this existing pump activity. Preserve the original evidence code and species boundary rather than relabeling every source as human IDA.

Summary: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump.

Reason: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump. Independent direct human alpha/beta oocyte currents, purified functional complexes and human structures support this existing pump activity. Preserve the original evidence code and species boundary rather than relabeling every source as human IDA.

Summary: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump.

Reason: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump. Independent direct human alpha/beta oocyte currents, purified functional complexes and human structures support this existing pump activity. Preserve the original evidence code and species boundary rather than relabeling every source as human IDA.

Summary: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump.

Reason: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump. Independent direct human alpha/beta oocyte currents, purified functional complexes and human structures support this existing pump activity. Preserve the original evidence code and species boundary rather than relabeling every source as human IDA.

Summary: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump.

Reason: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump. Independent direct human alpha/beta oocyte currents, purified functional complexes and human structures support this existing pump activity. Preserve the original evidence code and species boundary rather than relabeling every source as human IDA.

Summary: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump.

Reason: ATP1A1 is the catalytic alpha1 subunit of the Na/K pump. Independent direct human alpha/beta oocyte currents, purified functional complexes and human structures support this existing pump activity. Preserve the original evidence code and species boundary rather than relabeling every source as human IDA.

Summary: Refine the established alpha1/beta2 assembly interaction to protein heterodimerization activity.

Reason: The complete PMID:11027149 abstract explicitly tests human alpha1 with beta-subunit combinations in Xenopus oocytes, including beta2; independent PMID:10636900 also supports functional human alpha1/beta2 assembly. The original P14415 partner and source are preserved. The source is not rejected because its title also foregrounds nongastric H/K-ATPase. GO:0046982 specifies association with a nonidentical protein into a heterodimer and is a more informative molecular function than generic protein binding. The existing complex annotation remains a separate cellular-component statement. This refines an existing assertion; no NEW row or activity of the partner is assigned to ATP1A1.

Proposed replacements: protein heterodimerization activity

Summary: Keep protein binding unresolved pending the source-specific evidence.

Reason: The selected original study uses porcine lens membranes and added commercial Lck. Alpha1 IP followed by phosphotyrosine Western is a phosphorylation assay, not a LCK-alpha1 binding assay; the human Jurkat control does not resolve this target pair. Preserve the IPI assertion while the human pair/construct evidence remains unverified; do not remove it merely for species or title differences.

Summary: Retain protein binding as non-core context.

Reason: Retain TPT1/TCTP association as a non-core regulatory interaction. The cited abstracts describe pump-domain association and TCTP-dependent effects, corroborated by the immutable UniProt interaction record. Do not transfer SNX6 binding, Src kinase activity, or downstream cancer pathways to ATP1A1.

Summary: Retain protein binding as non-core context.

Reason: Retain NDRG1 association, corroborated by the immutable ATP1A1 UniProt interaction record. The exact source-specific proteomic pair cell was not inspected, so the original curated pair is deferred to without claiming a purified binary interaction or a distinct core.

Summary: Retain protein binding as non-core context.

Reason: The original target Results report reciprocal alpha1-Naked2 co-IP in transfected HEK293 cells with a CD147 negative control, following MDCK vesicle-cargo discovery. Retain association context; cargo presence does not make ATP1A1 an exocytic-machinery activity, and the interaction is not assigned a new adapter function.

Summary: Refine the established alpha1/beta1 assembly interaction to protein heterodimerization activity.

Reason: The cited study includes purified recombinant human alpha1/beta1 preparations and FXYD-dependent stabilization. Its separate rat construct experiment in HeLa is not relabeled as a human-protein assay. Independent human alpha1/beta1 structure in PMID:35803952 corroborates assembly; this does not assign alpha1 protein-folding chaperone activity. GO:0046982 specifies association with a nonidentical protein into a heterodimer and is a more informative molecular function than generic protein binding. The existing complex annotation remains a separate cellular-component statement. This refines an existing assertion; no NEW row or activity of the partner is assigned to ATP1A1.

Proposed replacements: protein heterodimerization activity

Summary: Retain protein binding as non-core context.

Reason: Retain TPT1/TCTP association as a non-core regulatory interaction. The cited abstracts describe pump-domain association and TCTP-dependent effects, corroborated by the immutable UniProt interaction record. Do not transfer SNX6 binding, Src kinase activity, or downstream cancer pathways to ATP1A1.

Summary: Retain protein binding as non-core context.

Reason: Human POST purification identifies ATP1A1, and endogenous co-IP supports association in HEK293/Jurkat cells. Retain this non-core regulatory complex context. PMCA calcium-pump inhibition in the same paper does not establish calcium transport by ATP1A1.

Summary: Refine the established alpha1/beta1 assembly interaction to protein heterodimerization activity.

Reason: Human-kidney coimmunoprecipitation in the cited paper places alpha1 in a beta1/AE1-containing complex. The direct purified AE1-beta1 affinity is not assigned to alpha1. The established alpha1/beta1 association is independently resolved by the human complex in PMID:35803952. GO:0046982 specifies association with a nonidentical protein into a heterodimer and is a more informative molecular function than generic protein binding. The existing complex annotation remains a separate cellular-component statement. This refines an existing assertion; no NEW row or activity of the partner is assigned to ATP1A1.

Proposed replacements: protein heterodimerization activity

Summary: Refine the established alpha1/beta1 assembly interaction to protein heterodimerization activity.

Reason: The exact ATP1A1-beta1 crosslink record in the original nuclear-proteomics source remains uninspected. Preserve that curated source assertion without a claim to reanalyzing the target pair; independently purified human alpha1/beta1 structural evidence in PMID:35803952 supports the more specific assembly function. GO:0046982 specifies association with a nonidentical protein into a heterodimer and is a more informative molecular function than generic protein binding. The existing complex annotation remains a separate cellular-component statement. This refines an existing assertion; no NEW row or activity of the partner is assigned to ATP1A1.

Proposed replacements: protein heterodimerization activity

Summary: Retain protein binding as non-core context.

Reason: The complete abstract explicitly reports RNF183 interaction with alpha1 as well as beta1. Retain non-core association with original partner accession preserved; construct species and direct binary binding were not independently resolved. Ubiquitination was demonstrated for beta1, not an intrinsic ATP1A1 ligase activity.

Summary: Refine the established alpha1/beta1 assembly interaction to protein heterodimerization activity.

Reason: The exact ATP1A1-beta1 record in the original human BioPlex table remains uninspected. Preserve the curated source assertion and its provenance; the independent human alpha1/beta1 complex structure in PMID:35803952 supports this assembly-function refinement without claiming new primary-table verification. GO:0046982 specifies association with a nonidentical protein into a heterodimer and is a more informative molecular function than generic protein binding. The existing complex annotation remains a separate cellular-component statement. This refines an existing assertion; no NEW row or activity of the partner is assigned to ATP1A1.

Proposed replacements: protein heterodimerization activity

Summary: Refine the established alpha1/beta1 assembly interaction to protein heterodimerization activity.

Reason: The exact beta1 pair record in the original human OpenCell matrix remains uninspected. Preserve its original provenance, while independent human alpha1/beta1 structural evidence in PMID:35803952 supports the specific assembly interaction. This is not a claim that the original matrix was reanalyzed. GO:0046982 specifies association with a nonidentical protein into a heterodimer and is a more informative molecular function than generic protein binding. The existing complex annotation remains a separate cellular-component statement. This refines an existing assertion; no NEW row or activity of the partner is assigned to ATP1A1.

Proposed replacements: protein heterodimerization activity

Summary: Retain protein binding as non-core context.

Reason: Retain NDRG1 association, corroborated by the immutable ATP1A1 UniProt interaction record. The exact source-specific proteomic pair cell was not inspected, so the original curated pair is deferred to without claiming a purified binary interaction or a distinct core.

Summary: Refine the established alpha1/beta1 assembly interaction to protein heterodimerization activity.

Reason: PMID:35803952 coexpresses human alpha1, beta1 and FXYD2 in HEK293F cells and purifies the complex for cryo-EM. The alpha1/beta1 association is directly present in the structural complex. Heterodimerization describes the alpha/beta pair within that larger assembly; it does not assert that the complete pump lacks the FXYD accessory subunit. GO:0046982 specifies association with a nonidentical protein into a heterodimer and is a more informative molecular function than generic protein binding. The existing complex annotation remains a separate cellular-component statement. This refines an existing assertion; no NEW row or activity of the partner is assigned to ATP1A1.

Proposed replacements: protein heterodimerization activity

Summary: Nucleotide/ATP binding is intrinsic to the catalytic alpha subunit and is supported by the independently characterized human pump.

Reason: Nucleotide/ATP binding is intrinsic to the catalytic alpha subunit and is supported by the independently characterized human pump. Retain this existing biochemical aspect of the single ion-exchange core; it does not define a second core.

Summary: Nucleotide/ATP binding is intrinsic to the catalytic alpha subunit and is supported by the independently characterized human pump.

Reason: Nucleotide/ATP binding is intrinsic to the catalytic alpha subunit and is supported by the independently characterized human pump. Retain this existing biochemical aspect of the single ion-exchange core; it does not define a second core.

Summary: Nucleotide/ATP binding is intrinsic to the catalytic alpha subunit and is supported by the independently characterized human pump.

Reason: Nucleotide/ATP binding is intrinsic to the catalytic alpha subunit and is supported by the independently characterized human pump. Retain this existing biochemical aspect of the single ion-exchange core; it does not define a second core.

Summary: Retain lysosomal membrane as non-core context.

Reason: The source explicitly reports alpha1 delivery from plasma membrane to lysosomes during RNF183-dependent turnover. Retain the existing localization in degradation context; it does not establish the lysosome as the principal site of ATP1A1 ion pumping.

Summary: ER location transferred from rat alpha1, whose own ER annotation rests on biosynthetic transit and on ER accumulation when ER-to-Golgi export is experimentally blocked; the pump is a plasma-membrane resident, so this is an over-annotation.

Reason: ORGANELLES check (2026-11-04), changed from KEEP_AS_NON_CORE. The ISS source is rat P06685, whose GO:0005783 row is an IDA from PMID:18768923 (BHF-UCL). That paper studies ankyrin-dependent ER-to-Golgi export of alpha1 in MDCK cells: alpha and beta subunits assemble in the ER and leave as a complex, and alpha1 accumulates in an apparent ER compartment only when export is blocked by an overexpressed eGFP-MAB peptide or when the ankyrin-binding sequence is deleted (with BiP retention, i.e. misfolding). That is the biosynthetic transit pool of a plasma-membrane pump plus perturbation-induced retention, not ER residence or ER activity; UniProt lists no ER location for human alpha1 (cell membrane, sarcolemma, axon, melanosome). Per the ER transit rule the row is an over-annotation rather than a minor resident pool. No sub-compartment row is added. Neighbouring Golgi row not re-reviewed here.

Summary: Retain Golgi apparatus as non-core context.

Reason: Retain the rat-ortholog curator-transferred secretory-pathway localization as biosynthetic/trafficking context. The functional pump core is at the plasma membrane; no new ER or Golgi ion-pumping role is inferred.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies.

Reason: Plasma-membrane localization is central to ATP1A1 ion exchange and independently established in human surface-localization, muscle and pump studies. Retain the original source assertion, explicitly deferring to the curator for the unread exact screen image or source-specific panel.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex.

Reason: Alpha1 is a catalytic component of the sodium:potassium-exchanging ATPase complex. Human alpha/beta functional assembly and alpha1/beta1/FXYD2 structure independently corroborate this existing complex membership. Preserve inherited PAINT/ortholog/complex-transfer provenance; the target in a PAINT donor list is legitimate, not circular evidence.

Summary: The InterPro IPR005775 mapping assigns potassium transport to a P-type cation pump.

Reason: The InterPro IPR005775 mapping assigns potassium transport to a P-type cation pump. ATP1A1 directly carries potassium across the membrane during Na/K exchange, corroborated by human pump-current measurements in PMID10636900. This existing broad process is compatible with the separately retained inward plasma-membrane transport annotation; duplicating that child as a replacement would add no coverage.

Summary: Potassium-coupled sodium extrusion maintains low intracellular sodium, making sodium homeostasis part of ATP1A1 pump activity.

Reason: Potassium-coupled sodium extrusion maintains low intracellular sodium, making sodium homeostasis part of ATP1A1 pump activity. This PAINT assertion inherits PTN000643123; human pump-current evidence independently supports the target function. The target appearing in the descendant evidence list is legitimate grounding, and no new judgment about the unread ancestral node placement is claimed.

Summary: Human alpha/beta isozymes expressed in Xenopus oocytes showed K-activated pump currents and differing apparent intracellular sodium affinities in PMID10636900.

Reason: Human alpha/beta isozymes expressed in Xenopus oocytes showed K-activated pump currents and differing apparent intracellular sodium affinities in PMID10636900. These measurements support the alpha1 transport mechanism maintaining intracellular sodium. Retain the curated homeostasis assertion without claiming that the paper measured every downstream sodium-dependent phenotype.

Summary: PMID19542013 measures regulation of alpha1/beta1 pump current and turnover, linking inhibition of sodium extrusion to intracellular sodium control.

Reason: PMID19542013 measures regulation of alpha1/beta1 pump current and turnover, linking inhibition of sodium extrusion to intracellular sodium control. The accessible abstract separates rabbit myocytes, oocyte constructs of unresolved donor species and pig-kidney enzyme. Retain the curated homeostasis claim with independent human pump support; beta1 glutathionylation is not alpha1 modification.

Summary: ARBA00086918 predicts intracellular sodium homeostasis.

Reason: ARBA00086918 predicts intracellular sodium homeostasis. ATP1A1 actively exports cytoplasmic sodium, and independent human alpha1 functional and structural studies support that mechanism. The electronic assertion is retained as the homeostatic consequence of this direct transport step, without inventing the ARBA rule training evidence.

Summary: The CPX-57 homologous-complex transfer assigns intracellular sodium homeostasis to the sodium pump.

Reason: The CPX-57 homologous-complex transfer assigns intracellular sodium homeostasis to the sodium pump. Its catalytic alpha1 subunit performs the sodium-export step; direct human pump evidence corroborates this function. Preserve complex-level ISS provenance rather than recasting this transferred assertion as a new human assay.

Summary: Retain osmosensory signaling pathway as non-core context.

Reason: Retain a possible osmosensory context explicitly described by similarity in the immutable UniProt record, involving SCN7A-dependent stimulation of the pump. This is an ortholog-supported signaling context, not evidence that ATP1A1 is itself a sodium sensory receptor or a separate signaling core.

Summary: Potassium translocation is one half of the ATP1A1 P-type sodium/potassium exchange cycle.

Reason: Potassium translocation is one half of the ATP1A1 P-type sodium/potassium exchange cycle. The combined mouse/Ensembl and InterPro IPR005775 inference is consistent with human pump-current and ion-bound structural evidence. Retain the existing potassium-transporter activity alongside the specific exchange activity, without proposing an independent potassium-only pump.

Summary: The NAS source PMID24688018 describes how unequal sodium export and potassium import generate outward current and an electrochemical gradient.

Reason: The NAS source PMID24688018 describes how unequal sodium export and potassium import generate outward current and an electrochemical gradient. Its experimental pumps are Xenopus alpha1/beta3; independent human alpha1 work supports the same main Na/K-exchange mechanism. The optional proton back-step is not required for this gradient-generating core.

Summary: Keep postsynaptic density unresolved pending the source-specific evidence.

Reason: The mouse-to-human electronic transfer names postsynaptic density, but the target-specific donor experiment and conserved compartment assignment were not inspected. Generic neuronal membrane expression does not by itself verify this specialized compartment. Preserve the assertion pending source-level resolution.

Summary: Combined mouse/Ensembl and InterPro mappings correctly place the multipass alpha1 protein in a membrane.

Reason: Combined mouse/Ensembl and InterPro mappings correctly place the multipass alpha1 protein in a membrane. The human pump has an established plasma-membrane location, already captured separately. Retain this broad source assertion as non-core localization context rather than replacing it with a duplicate plasma-membrane row.

Summary: The Q92123 ortholog transfer supports membrane localization of a conserved multipass sodium-pump subunit.

Reason: The Q92123 ortholog transfer supports membrane localization of a conserved multipass sodium-pump subunit. Its general compartment is correct and compatible with the specific human plasma-membrane annotations. Retain the existing source scope as non-core context; no donor experiment or new intracellular pump location is inferred.

Summary: PMID1975705 is rat-alpha1 rubidium-influx work supporting a membrane-associated pump.

Reason: PMID1975705 is rat-alpha1 rubidium-influx work supporting a membrane-associated pump. Retain this general location as non-core ortholog context, independently consistent with human alpha1 localization. The linked historical erratum remains unresolved, and this retention does not endorse its precise allele mechanism.

Summary: Retain polarized plasma-membrane localization of the functioning pump.

Reason: Retain polarized plasma-membrane localization of the functioning pump. Human prostate data support apical/lateral alpha1, while renal basolateral localization is independently established; there is no universal basolateral-only restriction. Original donor/evidence distinctions remain intact.

Summary: Retain polarized plasma-membrane localization of the functioning pump.

Reason: Retain polarized plasma-membrane localization of the functioning pump. Human prostate data support apical/lateral alpha1, while renal basolateral localization is independently established; there is no universal basolateral-only restriction. Original donor/evidence distinctions remain intact.

Summary: Retain polarized plasma-membrane localization of the functioning pump.

Reason: Retain polarized plasma-membrane localization of the functioning pump. Human prostate data support apical/lateral alpha1, while renal basolateral localization is independently established; there is no universal basolateral-only restriction. Original donor/evidence distinctions remain intact.

Summary: Retain polarized plasma-membrane localization of the functioning pump.

Reason: Retain polarized plasma-membrane localization of the functioning pump. Human prostate data support apical/lateral alpha1, while renal basolateral localization is independently established; there is no universal basolateral-only restriction. Original donor/evidence distinctions remain intact.

Summary: Retain polarized plasma-membrane localization of the functioning pump.

Reason: Retain polarized plasma-membrane localization of the functioning pump. Human prostate data support apical/lateral alpha1, while renal basolateral localization is independently established; there is no universal basolateral-only restriction. Original donor/evidence distinctions remain intact.

Summary: Retain phosphatase activity as non-core context.

Reason: Retain the mouse-to-human phosphatase annotation conservatively as a non-core biochemical property. The independently read original mouse-alpha1 H4-H5 loop study directly measures p-nitrophenylphosphate hydrolysis outside the ATP-binding site. This is not inferred merely from ATP hydrolysis, pump autodephosphorylation or PP2A acting on ATP1A1. The exact Ensembl donor lineage and physiological human substrate remain unresolved; no new phosphatase core is proposed.

Summary: The IDA assertion attributes ATP hydrolysis to the functional human Na/K isozymes characterized in PMID10636900.

Reason: The IDA assertion attributes ATP hydrolysis to the functional human Na/K isozymes characterized in PMID10636900. ATP cleavage drives the alpha-subunit phosphorylation cycle. The inspected source abstract describes pump currents and turnover rather than an independently reread phosphate-release assay; retain curator attribution with corroborating human ATP-bound structural evidence, without inventing that assay.

Summary: InterPro IPR001757 maps the catalytic P-type ATPase machinery to ATP hydrolysis.

Reason: InterPro IPR001757 maps the catalytic P-type ATPase machinery to ATP hydrolysis. Human ATP1A1 structures and functional pumps corroborate the ATP-coupled cycle. This describes chemical work performed by alpha1, not a separate ATPase core or a role assigned merely because ATP1A1 is necessary for transport.

Summary: ATP1A1-mediated potassium uptake maintains intracellular potassium.

Reason: ATP1A1-mediated potassium uptake maintains intracellular potassium. The PTN000643123 PAINT assertion agrees with direct human pump evidence; the retained target-self source is valid descendant grounding. The inherited node and individual donor experiments were not independently reconstructed in this follow-up.

Summary: PMID10636900 characterizes human alpha/beta pump currents activated by extracellular potassium in oocytes.

Reason: PMID10636900 characterizes human alpha/beta pump currents activated by extracellular potassium in oocytes. Potassium uptake by this pump provides the mechanistic basis for intracellular potassium homeostasis. Preserve the original IDA interpretation without extending it to every cellular potassium-regulatory pathway.

Summary: PMID19542013 measures alpha1/beta1 pump turnover and current under oxidative regulation, which affects pump-mediated potassium uptake.

Reason: PMID19542013 measures alpha1/beta1 pump turnover and current under oxidative regulation, which affects pump-mediated potassium uptake. Rabbit myocytes and the oocyte/pig preparations remain distinct from independently corroborating human alpha1 evidence. Retain the curated potassium-homeostasis consequence without assigning beta1 redox chemistry to alpha1.

Summary: ARBA00086105 predicts intracellular potassium homeostasis.

Reason: ARBA00086105 predicts intracellular potassium homeostasis. ATP1A1 directly imports potassium in its coupled transport cycle, consistent with human functional and structural studies. This biological consequence supports the electronic assertion; it does not identify a new signaling or potassium-sensing mechanism.

Summary: The CPX-57 complex transfer links Na/K-pump activity to intracellular potassium maintenance.

Reason: The CPX-57 complex transfer links Na/K-pump activity to intracellular potassium maintenance. Human alpha1 supplies the catalytic potassium-uptake step. Retain the existing homologous-complex ISS assertion with independent target corroboration and without implying a newly inspected CPX-57 experiment.

Summary: Retain T-tubule as non-core context.

Reason: Human atrial immunohistochemistry explicitly localizes alpha1/beta1 to T tubules in PMID19751721, corroborating the mouse transfer. Retain this specialized membrane compartment without making cardiac tissue a separate core function.

Summary: Retain T-tubule as non-core context.

Reason: Human atrial immunohistochemistry explicitly localizes alpha1/beta1 to T tubules in PMID19751721, corroborating the mouse transfer. Retain this specialized membrane compartment without making cardiac tissue a separate core function.

Summary: Retain axon as non-core context.

Reason: Retain axonal localization as curator-transferred neural context, explicitly by similarity in the immutable UniProt entry. It does not establish a distinct axon-specific transport activity.

Summary: This P05024 ortholog transfer assigns potassium binding to ATP1A1.

Reason: This P05024 ortholog transfer assigns potassium binding to ATP1A1. Potassium occupies transport sites during the pump cycle, and the human potassium-occluded structure in PMID35803952 independently corroborates binding on the target. Preserve the donor-based ISS code rather than replacing it with a structural IDA claim.

Summary: The P06685 rat-ortholog assertion concerns binding of potassium at the pump transport sites.

Reason: The P06685 rat-ortholog assertion concerns binding of potassium at the pump transport sites. Human ATP1A1 potassium-occluded structural evidence supports the same molecular interaction. The exact rat donor assay was not reread; this is corroboration of an existing transfer, not a claim that human and rat experimental records are identical.

Summary: The P06685 transfer assigns sodium binding to the catalytic subunit.

Reason: The P06685 transfer assigns sodium binding to the catalytic subunit. Human ATP1A1 structures in PMID35803952 resolve sodium-loaded states, independently supporting substrate occupancy. Binding is distinguished from the sodium-export process and does not create a second core.

Summary: PMID22797923 supports association of human ATP1A1 with ZNRF1/2 in a regulatory complex.

Reason: PMID22797923 supports association of human ATP1A1 with ZNRF1/2 in a regulatory complex. ATP1A1 is a ubiquitination substrate, not the E3 ligase. Retain the broad complex annotation as non-core context; the inspected evidence does not establish a more specific named GO complex. The publisher correction concerning control blots remains disclosed.

Summary: PMID18052210 purifies active human alpha1 paired with porcine His-tagged beta1 from Pichia and measures Na/K-ATPase activity and sodium dependence.

Reason: PMID18052210 purifies active human alpha1 paired with porcine His-tagged beta1 from Pichia and measures Na/K-ATPase activity and sodium dependence. This supports the catalytic mechanism underlying sodium transmembrane transport. Preserve the IGI partner and mixed-species complex; the abstract is not a direct reconstituted sodium-flux measurement.

Summary: Keep sperm flagellum unresolved pending the source-specific evidence.

Reason: The cited paper includes human alpha1 as well as alpha4, so its title is not grounds for removal. The exact alpha1 flagellar localization was not verified in the original target data; alpha4-specific localization or motility must not substitute for it. Preserve the IDA assertion pending that finite check.

Summary: Sodium export across the plasma membrane is the outward limb of ATP1A1 exchange.

Reason: Sodium export across the plasma membrane is the outward limb of ATP1A1 exchange. The PTN000643123 PAINT assertion agrees with human alpha1 currents and sodium-loaded structures. Target-self evidence is valid; no donor-count argument or uninspected tree-placement claim is introduced.

Summary: Human alpha1/beta complexes in PMID10636900 produce electrogenic pump currents with intracellular sodium dependence in Xenopus oocytes.

Reason: Human alpha1/beta complexes in PMID10636900 produce electrogenic pump currents with intracellular sodium dependence in Xenopus oocytes. These functional measurements support plasma-membrane sodium export by the human protein. The host species is not the protein species, and the existing IDA attribution is preserved.

Summary: PMID19542013 measures alpha1/beta1 pump current and turnover under redox regulation.

Reason: PMID19542013 measures alpha1/beta1 pump current and turnover under redox regulation. Sodium export is the relevant limb of the pump cycle, independently corroborated for human alpha1. Rabbit myocytes, pig enzyme and donor-unresolved oocyte constructs are not relabeled as direct human sodium-flux assays.

Summary: ARBA00089462 predicts plasma-membrane sodium export.

Reason: ARBA00089462 predicts plasma-membrane sodium export. This agrees with human ATP1A1 functional measurements and the direction of its coupled ion-exchange cycle. Retain the electronic assertion without claiming to have reconstructed the ARBA inference procedure.

Summary: The P05024 ortholog ISS assertion identifies sodium export across the plasma membrane.

Reason: The P05024 ortholog ISS assertion identifies sodium export across the plasma membrane. Independent human alpha1 pump currents corroborate the conserved outward sodium-transport step. The original donor-specific provenance remains distinct from the additional human evidence.

Summary: The CPX-57 homologous-complex transfer describes sodium export by the Na/K pump.

Reason: The CPX-57 homologous-complex transfer describes sodium export by the Na/K pump. ATP1A1 performs the catalytic outward sodium step in the human complex, corroborated by human functional studies. Retain ISS provenance; complex transfer is not an additional human experiment.

Summary: Sarcolemmal localization is a plasma-membrane site of the established pump and is directly supported by human skeletal-muscle alpha1 fractionation/immunocytochemistry in PMID7711835.

Reason: Sarcolemmal localization is a plasma-membrane site of the established pump and is directly supported by human skeletal-muscle alpha1 fractionation/immunocytochemistry in PMID7711835. Retain the inherited and ortholog annotations as corroborated localization of the same core.

Summary: Sarcolemmal localization is a plasma-membrane site of the established pump and is directly supported by human skeletal-muscle alpha1 fractionation/immunocytochemistry in PMID7711835.

Reason: Sarcolemmal localization is a plasma-membrane site of the established pump and is directly supported by human skeletal-muscle alpha1 fractionation/immunocytochemistry in PMID7711835. Retain the inherited and ortholog annotations as corroborated localization of the same core.

Summary: Sarcolemmal localization is a plasma-membrane site of the established pump and is directly supported by human skeletal-muscle alpha1 fractionation/immunocytochemistry in PMID7711835.

Reason: Sarcolemmal localization is a plasma-membrane site of the established pump and is directly supported by human skeletal-muscle alpha1 fractionation/immunocytochemistry in PMID7711835. Retain the inherited and ortholog annotations as corroborated localization of the same core.

Summary: Retain melanosome as non-core context.

Reason: Retain melanosome localization as a proteomic compartment context. The immutable UniProt record explicitly attributes alpha1 detection in stage I-IV melanosome fractions to PMID17081065; the original target peptide table was not independently reread. This does not imply that melanosomal pumping defines the major function.

Summary: Retain melanosome as non-core context.

Reason: Retain melanosome localization as a proteomic compartment context. The immutable UniProt record explicitly attributes alpha1 detection in stage I-IV melanosome fractions to PMID17081065; the original target peptide table was not independently reread. This does not imply that melanosomal pumping defines the major function.

Summary: Retain transmembrane transporter binding as non-core context.

Reason: Retain the ortholog-transferred transporter-association context. ATP1A1 participates in complexes with other transport proteins, including the SCN7A-associated context in UniProt and the human AE1/beta1-containing complex. Do not infer that every complex association establishes direct binary binding or replace the existing donor-specific assertion with an invented partner.

Summary: Keep membrane raft unresolved pending the source-specific evidence.

Reason: The lipid-raft transfer names an ortholog, but the target-specific source fractionation and conservation were not inspected. General plasma-membrane residence is insufficient to verify raft partitioning. Preserve the ISS assertion without declaring the location false.

Summary: Retain protein-folding chaperone binding as non-core context.

Reason: Retain binding to beta subunits in their pump-maturation context. GO:0051087 includes chaperones that promote nascent-protein folding or transport; the human beta combinations support alpha maturation, association and cell-surface functional expression. This does not make ATP1A1 a chaperone, and the exact source folding panels were not all reread. No separate protein-folding core is proposed.

Summary: Retain protein-folding chaperone binding as non-core context.

Reason: Retain binding to beta subunits in their pump-maturation context. GO:0051087 includes chaperones that promote nascent-protein folding or transport; the human beta combinations support alpha maturation, association and cell-surface functional expression. This does not make ATP1A1 a chaperone, and the exact source folding panels were not all reread. No separate protein-folding core is proposed.

Summary: Retain protein-folding chaperone binding as non-core context.

Reason: Retain binding to beta subunits in their pump-maturation context. GO:0051087 includes chaperones that promote nascent-protein folding or transport; the human beta combinations support alpha maturation, association and cell-surface functional expression. This does not make ATP1A1 a chaperone, and the exact source folding panels were not all reread. No separate protein-folding core is proposed.

Summary: Retain protein-folding chaperone binding as non-core context.

Reason: Retain binding to beta subunits in their pump-maturation context. GO:0051087 includes chaperones that promote nascent-protein folding or transport; the human beta combinations support alpha maturation, association and cell-surface functional expression. This does not make ATP1A1 a chaperone, and the exact source folding panels were not all reread. No separate protein-folding core is proposed.

Summary: The mouse Q8VDN2/Ensembl inference assigns sodium homeostasis to alpha1.

Reason: The mouse Q8VDN2/Ensembl inference assigns sodium homeostasis to alpha1. Direct sodium extrusion by the human pump supports the general claim; the separately retained intracellular-homeostasis and export annotations provide finer detail. An existing broad source assertion is not a new redundancy requiring manufacture of another child annotation.

Summary: Retain relaxation of cardiac muscle as non-core context.

Reason: Retain cardiac contraction/relaxation context of pump-generated sodium gradients and coupled NCX calcium handling. The cited FXYD1 article is a review, and ATP1A1 does not directly perform calcium exchange. These specialized physiological consequences do not create a second core or a new process annotation.

Summary: Retain photoreceptor inner segment membrane as non-core context.

Reason: The original target Results use Xenopus alpha1 sequence in transgenic Xenopus photoreceptors and directly locate it at the inner-segment plasma membrane. Retain the human ISS assertion as ortholog-supported specialized localization; only alpha4 in that comparison is human. No direct human alpha1 experiment is claimed.

Summary: Detected in an extracellular-vesicle proteome. The protein is plausible EV content, but this is not where it functions.

Reason: Plasma-membrane Na+/K+-ATPase. Transmembrane/lipid-anchored protein of the plasma membrane or endosomal system (UniProt); such proteins are expected EV contents (MISEV2018 (PMID:30637094) category 1). True, but not its core location. (Manual re-review for OMICS_EVIDENCE, 2026-10-10; previous action: UNDECIDED.)

Summary: Detected in an extracellular-vesicle proteome. The protein is plausible EV content, but this is not where it functions.

Reason: Plasma-membrane Na+/K+-ATPase. Transmembrane/lipid-anchored protein of the plasma membrane or endosomal system (UniProt); such proteins are expected EV contents (MISEV2018 (PMID:30637094) category 1). True, but not its core location. (Manual re-review for OMICS_EVIDENCE, 2026-10-10; previous action: UNDECIDED.)

Summary: Detected in an extracellular-vesicle proteome. The protein is plausible EV content, but this is not where it functions.

Reason: Plasma-membrane Na+/K+-ATPase. Transmembrane/lipid-anchored protein of the plasma membrane or endosomal system (UniProt); such proteins are expected EV contents (MISEV2018 (PMID:30637094) category 1). True, but not its core location. (Manual re-review for OMICS_EVIDENCE, 2026-10-10; previous action: UNDECIDED.)

Summary: Independent intact-oocyte pump-current evidence supports this steroid-stimulus response as non-core.

Reason: PMID11546672 measures ouabain binding in isolated human membrane preparations; those inspected assays alone do not establish a cellular response. Independent PMID10636900 Methods, voltage-dependence Results and Figure 6 compare currents before and after 100 micromolar ouabain in intact Xenopus oocytes expressing human alpha1/beta1, with endogenous currents subtracted. This functional inhibition is a change in cellular activity consistent with GO:0071383, and ouabain is classified as a steroid hormone. Retain the existing assertion as non-core using this additional evidence, without attributing the current assay to PMID11546672 or inferring a general endocrine-signaling function. The official ChEBI record explicitly asserts CHEBI:472805 (ouabain) is_a CHEBI:26764 (steroid hormone), independently of its is_a CHEBI:38092 (cardenolide glycoside) relation. This retention is bounded to the pharmacological effect on cellular pump current in the stated Xenopus host, not a rule that any ligand binding by any enzyme establishes a physiological response process.

Summary: Active human alpha1/porcine beta1 complexes purified in PMID18052210 show potassium-dependent Na/K-ATPase activity.

Reason: Active human alpha1/porcine beta1 complexes purified in PMID18052210 show potassium-dependent Na/K-ATPase activity. This is consistent with the potassium-translocation limb of the pump. Keep the IGI partner and source scope; the inspected abstract does not establish a separate purified potassium-flux experiment.

Summary: Retain cardiac muscle cell action potential involved in contraction as non-core context.

Reason: Retain cardiac contraction/relaxation context of pump-generated sodium gradients and coupled NCX calcium handling. The cited FXYD1 article is a review, and ATP1A1 does not directly perform calcium exchange. These specialized physiological consequences do not create a second core or a new process annotation.

Summary: Retain membrane repolarization as non-core context.

Reason: Retain the electrogenic pump contribution to repolarization as specialized physiological context with curator deference. The cited abstract includes rabbit cardiac myocytes and heterologous constructs whose species is not identified there; no direct human repolarization assay is claimed. General pump-current evidence supports the biology without making this a separate core.

Summary: Retain membrane repolarization during cardiac muscle cell action potential as non-core context.

Reason: Retain the electrogenic pump contribution to repolarization as specialized physiological context with curator deference. The cited abstract includes rabbit cardiac myocytes and heterologous constructs whose species is not identified there; no direct human repolarization assay is claimed. General pump-current evidence supports the biology without making this a separate core.

Summary: The cardiac intercellular electrical-coupling term exceeds the demonstrated pump/contractility mechanism.

Reason: The annotation is too specific for the established pump/contractility evidence. GO:0086064 concerns current passing between adjacent cytoplasms through intercellular protein channels. The cited mouse beta1-knockout paper measures secondary alpha1 reduction, pump activity and cardiac calcium/contractile physiology, not that intercellular step. This is a process-scope overannotation, not a title-based beta1 misattribution or a denial of ATP1A1 cardiac relevance. Preserve the original TAS/ARBA assertions and do not manufacture a new process.

Summary: The cardiac intercellular electrical-coupling term exceeds the demonstrated pump/contractility mechanism.

Reason: The annotation is too specific for the established pump/contractility evidence. GO:0086064 concerns current passing between adjacent cytoplasms through intercellular protein channels. The cited mouse beta1-knockout paper measures secondary alpha1 reduction, pump activity and cardiac calcium/contractile physiology, not that intercellular step. This is a process-scope overannotation, not a title-based beta1 misattribution or a denial of ATP1A1 cardiac relevance. Preserve the original TAS/ARBA assertions and do not manufacture a new process.

Summary: Retain proton transmembrane transport as non-core context.

Reason: Retain the existing NAS proton-transport claim in its measured ortholog context. Xenopus alpha1/beta3 pumps can admit protons through a reversible back-step, including at physiological external Na/K; the step is not obligatory for the Na/K cycle. Human physiological relevance remains uncertain, so no additional proton-pump core or new term is proposed.

Summary: Independent intact-oocyte pump-current evidence supports the glycoside response as non-core.

Reason: PMID11546672 supports glycoside binding in isolated membranes, while independent PMID10636900 measures ouabain-sensitive currents in intact Xenopus oocytes expressing human alpha1/beta1. The before/after ouabain comparison, with endogenous current subtracted, supplies a functional response endpoint beyond ligand affinity alone. Retain the existing response to glycoside as non-core, preserving the original IDA/reference tuple and recording PMID10636900 as separate corroboration. This does not imply glycoside metabolism, a new signaling core, or a native human-cell experiment.

Summary: Detected in an extracellular-vesicle proteome. The protein is plausible EV content, but this is not where it functions.

Reason: Plasma-membrane Na+/K+-ATPase. Transmembrane/lipid-anchored protein of the plasma membrane or endosomal system (UniProt); such proteins are expected EV contents (MISEV2018 (PMID:30637094) category 1). True, but not its core location. (Manual re-review for OMICS_EVIDENCE, 2026-10-10; previous action: UNDECIDED.)

Summary: Human alpha1/alpha2 and chimeric constructs in Xenopus oocytes were tested for ouabain-binding kinetics in PMID14742675.

Reason: Human alpha1/alpha2 and chimeric constructs in Xenopus oocytes were tested for ouabain-binding kinetics in PMID14742675. The official ChEBI record explicitly states CHEBI:472805 is_a CHEBI:26764 (steroid hormone), alongside its cardenolide-glycoside classification. The binding MF is therefore supported and remains non-core; this does not establish an endocrine signaling process.

Summary: Potassium import is the inward limb of plasma-membrane Na/K exchange.

Reason: Potassium import is the inward limb of plasma-membrane Na/K exchange. The PTN000643123 PAINT assertion is independently supported by human alpha1 pump-current evidence. The target among descendant sources is not circular, and this follow-up does not reassign an unread ancestral node.

Summary: PMID10636900 directly characterizes K-activated currents of human alpha/beta pumps in Xenopus oocytes.

Reason: PMID10636900 directly characterizes K-activated currents of human alpha/beta pumps in Xenopus oocytes. This supports the inward potassium limb of electrogenic exchange across the cell surface. Retain the source IDA assertion without treating the frog expression host as evidence against a human protein assay.

Summary: Alpha1/beta1 current and turnover measurements in PMID19542013 support functioning Na/K exchange, whose inward limb imports potassium.

Reason: Alpha1/beta1 current and turnover measurements in PMID19542013 support functioning Na/K exchange, whose inward limb imports potassium. Independent human alpha1 evidence corroborates the transport direction. The rabbit, pig and donor-unresolved oocyte preparations remain explicitly separate, and beta1 glutathionylation is not assigned to alpha1.

Summary: ARBA00090368 predicts potassium import across the plasma membrane.

Reason: ARBA00090368 predicts potassium import across the plasma membrane. Human alpha1 pump currents and potassium-occluded structures corroborate this inward transport step. The electronic source is retained without inferring an additional potassium-channel activity.

Summary: This P05024 ortholog transfer concerns inward potassium transport by the plasma-membrane pump.

Reason: This P05024 ortholog transfer concerns inward potassium transport by the plasma-membrane pump. Human alpha1 K-activated currents independently corroborate that direction. Keep the original ISS provenance rather than converting the donor transfer into human IDA.

Summary: The P06685 rat-ortholog source supports potassium uptake by the Na/K-pump cycle.

Reason: The P06685 rat-ortholog source supports potassium uptake by the Na/K-pump cycle. Independent human pump function supports the same activity, while the exact rat experiment remains outside this bounded follow-up. Retain this existing transfer as part of the single exchange core.

Summary: The CPX-57 homologous-complex assertion assigns plasma-membrane potassium import to the pump.

Reason: The CPX-57 homologous-complex assertion assigns plasma-membrane potassium import to the pump. Human ATP1A1 provides its catalytic inward potassium step. Retain the complex-transfer source and the independently corroborated function without inventing a target-specific assay for CPX-57.