EFL1 evidence notes

2026-10-18: cytosolic ribosome maturation

EFL1 is a GTPase that acts with SBDS during late 60S maturation. Human-protein biochemistry measures GTP hydrolysis and SBDS-dependent eIF6 release; removing this anti-association factor permits subunit joining. Ribosome binding, nucleotide binding and hydrolysis belong to this integrated mechanism. They do not establish routine translation elongation or a separate general role in cellular GTP homeostasis. PMID:21536732 and PMID:26479198 support the core mechanism.

PMID:21536732 uses human EFL1 produced in yeast and human SBDS with mouse pre-60S particles or rabbit reticulocyte 60S particles. The mouse genetic perturbation is Sbds loss. Catalytic and omission controls support EFL1-dependent hydrolysis/release, while SBDS K151N can uncouple hydrolysis from eIF6 displacement. PMID:26479198 uses human factors on Dictyostelium particles; the local EFL1 map supports domain-level fitting, not atomic contacts. Static GMPPCP structures do not establish the exact timing of hydrolysis.

SBDS association and experimental scope

PMID:25991726 directly tests the human EFL1–SBDS pair by fluorescence anisotropy, with SBDS S143L and folding controls; most detailed exchange kinetics use yeast EFL1. PMID:30545121 likewise distinguishes human anisotropy from yeast SAXS/two-hybrid/modeling experiments. The current stable interaction record is EBI-21463457. PMID:39251607 contributes a different observation: SBDS-bait/EFL1-prey BioID proximity in K562 cells, represented by EBI-56912423. The screen includes matched controls but its target-specific quantitative supplement was not recovered. Proximity is not a direct contact measurement.

All three positive source assertions are retained as non-core generic binding. The project-specific instruction retains supported generic associations when no evidence-backed specific replacement is established. SBDS exchange-factor activity does not itself establish enzyme class, and the direct pair assays do not establish GTP-state-dependent binding. There is no basis to remove the positive interactions or invent an independent adaptor activity.

Propagation and products

The portable analysis reconstructs the exact target tree path, five ancestral IBD assertions, thirteen donor joins and two sufficient ARBA rule alternatives. Self-donation is valid. Distinct elongation-function loss assertions do not negate EFL1 GTPase or assembly activity. Current donor matches are separated from experimental records, and the combined yeast EFT1/EFT2 UniProt entry is kept explicit.

Both official natural sequences are reconstructed: Q7Z2Z2-1 is 1,120 residues and Q7Z2Z2-2 is 1,069 residues, lacking positions 32–82. The historical unversioned NP_078856 construct reference is insufficient to prove which exact current natural product was tested. No functional equivalence is inferred. The central unresolved questions are hydrolysis timing and the shorter product's activity.

Source access and provenance

All fifteen imported source assertions are preserved: eight ACCEPT, two MODIFY to ribosomal large subunit binding, and five KEEP_AS_NON_CORE. No NEW assertion or new publication quotation is added. The normal PMID:21536732 and PMID:25991726 files remain abstract-only, but genuine full originals were separately read in the operative sections recorded in the source guide. The optional access keys are omitted for those two references; their reference notes and source guide distinguish the abstract-only normal caches from the separately inspected full originals. The machine caches are unchanged. The other three used originals are available as normal full-text caches. No figure-pixel or supplementary-data inspection is claimed.

The normal fetch completed in an isolated workspace. The genuine Falcon attempt failed with HTTP 403, and the Perplexity-lite fallback failed with HTTP 401 insufficient quota. No provider report was fabricated. Literature assessment therefore uses the actual primary sources and explicit database evidence described above. The source guide records exact methods, stable interaction identifiers and public original locators.

Follow-up: project policy and evidence navigation

The three supported generic-binding rows remain KEEP_AS_NON_CORE under the explicit ClinGen curation instruction at projects/CLINGEN_MENDELIAN.md, lines 2976–2978 of the submitted head. That instruction deliberately differs from the annotation-reviewer skill's generic informational-exclusion policy and applies to this project; it is not a legacy-only exemption. The human anisotropy experiments remain direct pair evidence, while the BioID source remains a controlled proximity observation with spoke expansion, not a binary contact assay. No informative supported binding replacement was established, and no new activity is inferred from association.

GO:0046039 is a current, nonobsolete GTP metabolic-process term. The source measures GTP hydrolysis as part of EFL1-dependent ribosome maturation. Its non-core disposition is retained; the summary now states that relationship without suggesting a missing specific replacement. The displayed and shorter product descriptions are limited to their established sequence lengths and deletion. Existing construct-provenance and functional-equivalence limits above remain applicable.

The source guide now supplies exact published-cache paths, line ranges, checksums and pinned links, together with section anchors and saved-original hashes for the two separately inspected full papers. Those original details are not claimed to occur in the abstract-only caches. Reference-only support remains intentional; no new publication quotation is added. The single integrated GTPase/ribosome-maturation core, all fifteen source assertions and actions, natural-product identifiers and sequence note, existing raw-input archive and replay are unchanged. Large-subunit engagement remains part of the same mechanism, without a new independent core or reclassifying the directly measured EFL1 activity as a complex-only contribution.