EIF2B1 review notes

2026-10-20: evidence and scope

EIF2B1 is the alpha subunit of eIF2B. The integrated core describes its structural and regulatory contribution to the cytosolic nucleotide-exchange complex and cytoplasmic translation initiation. Purified human alpha homodimers and reconstitution with the other four subunits in PMID:29599213 provide participation evidence. Alpha-free complexes retain activity, and isolated alpha is not assigned autonomous exchange or hydrolase activity. PMID:27023709 includes a human translation comparator within a study whose detailed structural work concerns Schizosaccharomyces pombe; the translation endpoint is distinguished from a direct alpha-only GDP-exchange assay.

All 53 imported assertions are retained with their source identities, qualifiers and partner contexts: 22 ACCEPT, 14 MODIFY, 14 KEEP_AS_NON_CORE and 3 UNDECIDED. No new assertion, biological removal or source-lifecycle retirement is proposed. The generic binding decisions follow the specific instruction in CLINGEN_MENDELIAN: supported, biologically correct protein binding remains non-core when no evidence-backed subclass is established. Eight partner-class refinements use independent partner records and exact positive pairs; they do not transfer partner enzymatic or signaling activity to EIF2B1. The NTAQ1 human catalytic assignment is explicitly inferred by similarity to mouse, and the adrenergic-receptor pairs use mouse receptor tails with human EIF2B1.

The two official natural products remain Q14232-1 (305 aa) and Q14232-2 (222 aa). The shorter sequence retains residues 1–161, replaces the canonical 162–222 segment and lacks 223–305. Its assembly and regulatory equivalence has not been demonstrated. Historical M1/M14/M20 engineered starts in PMID:9235896 are not that natural splice product. The canonical 305-aa sequence matches the alpha chains in the structure associated with PMID:31048492; current RIKEN plasmid identity is not retrospective proof of every historical assay construct.

The normal publication-cache flags remain unchanged. Actual reading varied from complete abstracts to selected or complete operative original sections, as recorded in the source guide. PMID:15060152 has a partial normal cache despite its full-text flag; selected original cloning and complex-formation sections independently resolve human alpha membership. PMID:25858979 main text and captions were inspected, but supplementary Methods were unavailable. PMID:31048492 remains abstract-level article evidence supplemented by authentic structural and sequence resources, without a claimed Methods read.

Three source-specific assertions remain unresolved. PMID:12499492 does not provide accessible operative evidence for the imported human heat-response context. The inspected autopsy/genotype and oligodendrocyte sections of PMID:15217090 do not resolve alpha-specific participation; disease genotypes in other subunits are not by themselves a misattribution claim. PMID:8626696 reports activation of whole-complex exchange in stimulated human T cells, but does not resolve the alpha-specific receptor-signaling assertion in the inspected text. These uncertainties do not negate independently supported complex function.

The receptor-associated peripheral-membrane pool in PMID:9235896 is retained as contextual localization. The integrated core uses cytosol, supported by the target's own Reactome entity. Valid PAINT inheritance is retained, including the human target's own experimental premise at an ancestral node. Rat donor response annotations are kept with their whole-complex and organismal limits.

The portable analysis reproduces the source joins, sequence comparisons, PAINT paths, product reconstruction and Reactome chains from a frozen database-input archive. It distinguishes curated reference identity from experimental inserts. No publication quotations were added. The genuine Falcon request and its configured fallback failed with HTTP403/401, so no provider-generated report exists; the evidence assessment uses the cited sources and manual notes.

2026-10-21: relation review and unresolved source scope

The two UniProt IDA records for GO:0005085 from PMID:25858979 and PMID:27023709 retain their imported enables qualifier and ACCEPT action. A separate probable source-defect query now asks UniProt to check contributes_to: the primary evidence supports alpha participation in the exchange complex, while the inspected assays do not attribute nucleotide-exchange execution to alpha itself. GO relation guidance distinguishes these relations. The cause is unknown; the query has not been reported upstream. This updates the earlier interpretation of preserved qualifiers without changing the source records or the contribution-based core. The distinction is not a requirement that a catalytic protein function in isolation.

The three UNDECIDED assertions remain source-specific. The early rise of whole-eIF2B activity after T-cell stimulation in PMID:8626696 does not itself establish alpha participation in the receptor-initiated signaling pathway. The PMID:12499492 abstract does not resolve the imported human heat-response claim. The inspected PMID:15217090 autopsy/genotype sections identify EIF2B5 and EIF2B2 cases but do not independently resolve alpha-specific development. A sibling-subunit review does not add primary evidence to these assertions, and neither a different foregrounded subunit nor an unavailable section proves curator error. The separately evidenced rat heat-response context remains non-core.

Questions and a matched-product experiment now make the 222-aa product's unresolved assembly/regulatory equivalence explicit. Phosphorylated-eIF2 recognition is considered within the same regulatory mechanism. The unavailable PMID:31048492 operative text is an access limitation of this assessment, not a claim that the field has never resolved the interface. No separate binding term or duplicate core is inferred from the abstract or deposited sequence. The existing source guide retains public original URLs, exact access scopes and data hashes. No new publication quotations, annotations, cache edits or changes to the two official product records are introduced.