GABRB2: evidence and source scope

GABRB2 encodes a beta subunit of the ionotropic GABA-A receptor. Human recombinant structures and functional comparisons identify its contribution to GABA-binding interfaces and the shared chloride pore; native human brain assemblies independently establish beta2 membership. The central mechanism is receptor-mediated chloride conductance and postsynaptic signaling. The review keeps one core function and adds no annotation.

The review contains all current judgments, the core and 40 individual reference assessments. The source archive preserves all 66 original assertions, literal source contexts and dates, four current product sequences, seven actual IBD placements and the urinary-fraction extension. It does not repeat the current decisions, core or reference assessments.

Receptor mechanism and natural products

Selected original PMID:29950725(https://pubmed.ncbi.nlm.nih.gov/29950725/) Results and Methods establish human alpha1/beta2/gamma2 receptor architecture with functional comparisons. The cryo-EM construct has engineered intracellular loops, so it is not assigned to a current natural splice accession. Selected native human-brain PMID:39843743(https://pubmed.ncbi.nlm.nih.gov/39843743/) Results/Methods establish beta2-containing and mixed beta2/beta3 assemblies in alpha1-selected neurosurgical samples. Mixed positions, sample selection and unresolved splice identities limit extrapolation; no direct beta2–neuroligin interaction or beta2/beta2 lamotrigine site is inferred.

Official sequence records identify displayed P47870-2 as 512 residues, P47870-1 as 474, P47870-3 as 313 and P47870-4 as 372. All four direct FASTAs and feature-based reconstructions agree. The original PMID:19763268(https://pubmed.ncbi.nlm.nih.gov/19763268/) instead reports short experimental forms of 314 and 373 residues. These historical lengths are preserved without silently equating them to the current sequences. Human-brain transcript observations, engineered minigenes, tagged receptor assays and T365A comparisons have distinct scopes. The short experimental forms lack TM4 but produced currents with alpha1; domain architecture alone does not establish functional loss.

Phylogeny and source transfers

The actual retained PTHR18945 tree, alignment, cluster sequence and literal IBD records contain the exact 512-residue target at PTN002498410. Six assertions descend from PTN008566841; plasma-membrane localization descends from PTN001054635. All seven placements are supported. The current plasma-membrane donor list differs from the later retained IBD list; both dated contexts remain in the archive. Target self-donors are valid evidence, not circularity.

Official mouse P63137 and rat P63138 records were traced to their actual source assertions. Selected original PMID:26179122(https://pubmed.ncbi.nlm.nih.gov/26179122/) Results/Methods establish mouse beta2-dependent postsynaptic currents/potentials and beta2-specific synaptic clusters. Selected original PMID:27129275(https://pubmed.ncbi.nlm.nih.gov/27129275/) uses mouse subunits and neurons, with extracellular-domain competition and a bicuculline contact-count control supporting a structural contribution to synapse assembly. This remains a contextual role, with the exact presynaptic ligand and in-vivo sufficiency unresolved.

The newly recovered original PMID:17021187(https://pubmed.ncbi.nlm.nih.gov/17021187/) Methods, Results and Discussion establish a genuine mouse beta2 cochlear phenotype and directly distinguish normal P10/P21 efferent development from terminal degeneration by six weeks. Later hair-cell, neuronal-response and cochlear changes support maintenance of the mature system. Four specific developmental transfers are therefore marked over-annotated on this source-specific evidence; no universal developmental absence, wrong-gene conclusion or new maintenance annotation is asserted. The extraction lacks complete figure images/captions, quantitative Table1 cells and supplements.

The actual CPX-280 record is rat alpha4/beta3/delta. It is retained as a homologous-complex source, while independent human beta2 structures establish the broad complex-membership claim. The official method permits such complex inference; CPX-280 is not rewritten as a directly observed beta2 assembly.

Contextual and unresolved observations

The accessed PMID:18281286(https://pubmed.ncbi.nlm.nih.gov/18281286/) abstract directly reports histamine currents in artificial beta2/beta3 homomers and histamine potentiation, rather than agonism, in alpha1/beta2(/gamma2) heteromers. Full Methods were not recovered and clone species is not inferred from the oocyte host or donor record. The reported histamine EC50 for artificial beta2 homomers is 212 micromolar; histamine response remains non-core.

Recombinant alpha1/beta2/delta pharmacology in PMID:18204487(https://pubmed.ncbi.nlm.nih.gov/18204487/) is distinguished from demonstrated human extrasynaptic deployment. Rat beta2/3-reactive immunogold localization in PMID:9464994(https://pubmed.ncbi.nlm.nih.gov/9464994/) supplies independent extrasynaptic context but cannot isolate beta2 or establish human ambient-GABA signaling. The actual selected PMID:35355020(https://pubmed.ncbi.nlm.nih.gov/35355020/) experiments use beta3-containing assemblies; its incoming beta2 NAS rows retain background scope and do not become beta2 histamine-site experiments.

The complete main text and captions/table of PMID:33234346(https://pubmed.ncbi.nlm.nih.gov/33234346/) resolve the negative-regulation attribution: CLPTM1 reduces receptor trafficking/transmission, while SHISA7 modulates receptor kinetics and targeting. Beta2-containing receptors are the regulated entities. The source-specific NAS attribution is removed; no universal absence of beta2 regulation is asserted. The dendritic-spine claim from 25025157 and two cytoplasmic-vesicle claims traced to 25172774 remain unresolved. Actual 25025157 surface assays use beta2/3-reactive labeling, and the inspected spine paragraph concerns a PSD95-GFP control. The 25172774 abstract identifies gamma2-containing transport vesicles without resolving beta2. These limits do not establish that the complete originals lack the curator’s evidence.

The authentic expanded urinary-proteomics table assigns GABRB2/NP_068711 at row 443 with one peptide and a historical isoform1 label. No peptide sequence was recovered, so modern product identity, topology and vesicle biogenesis are unestablished. The non-core PMID:19056867(https://pubmed.ncbi.nlm.nih.gov/19056867/) occurrence retains its literal urine extension.

Reactome and access accounting

Official R-HSA-975340 reaches P47870 through catalyst 975314, GABA-bound 975268, receptor-set 5340318, heteropentamer 5357502, beta-set 975288 and target 975381 (residues 26–512). R-HSA-977443 is the broader receptor pathway. The ERBB4 pathway includes an inferred GABRA1-mediated receptor association; no direct beta2–ERBB4 interaction or new beta2 signaling function follows from that membership.

All 27 PMID identities were checked against authentic PubMed records. Access differs by paper: selected full originals, actual cached full-text passages, original figure legends and abstract-only records are individually distinguished in the review. Failed responses are excluded from evidence. Official descriptions of all nine GO methods were read; method verification does not certify every uninspected individual assay or complete ARBA rule. Normal caches remain unmodified.

Genuine native acquisition produced the expected 66-row seed and 16-column export. The archive records actual raw-to-native joins, the verified urine restoration, all 33 source hashes/availability headers and the four initial cache quotation checks. Nine source files were reused from main, nine additional files from the published GABRA1 head and fifteen fetched through the native missing-only path. All reused bytes remain exact. The four initial excerpts remain exact. Seven additional excerpts make the four developmental over-annotation judgments, the CLPTM1 attribution correction and two abstract-scoped splice findings directly checkable. Across all eleven current occurrences, the per-paper word counts remain at or below 25, including repetitions; the archive records offsets and hashes without repeating their text. Native 27789573 Methods now confirm the human constructs and assay setup, while figure-image and splice-mapping limits remain explicit. Research notes use citations and paraphrases. Initial default validation and strict GOA reconciliation passed with zero advisories, and the initial status audit computed COMPLETE while preserving all three UNDECIDED judgments. Follow-up default validation, strict GOA reconciliation, native EDIT history, computed COMPLETE status audit, private rendering and scoped whitespace checks passed with zero advisories. All three UNDECIDED judgments and all source bytes remain unchanged.

Receptor activity scope

The original GOA relationships remain literal machine provenance. Receptor ACCEPTs and the three channel-term refinements describe beta2 within assembled receptors, consistent with the core contribution to the shared channel mechanism. They do not assert that an isolated beta2 chain independently reproduces the native channel. No WRONG_QUALIFIER source defect is inferred merely from differing source relationships.