RPL36AL curation notes

Date: 2026-07-18

Research provenance

The required automated deep-research run was attempted with Falcon and the
configured Perplexity-lite fallback. Falcon returned HTTP 402 and
Perplexity-lite returned HTTP 401 because its quota was unavailable. Neither
provider produced a usable output, and no provider-labelled file was authored
manually. This review therefore uses the fetched reviewed UniProt record, the
complete GOA set, cached primary publications, manually inspected open article
text, and the current QuickGO term record. The detailed synthesis is in
RPL36AL-deep-research-manual.md.

Identity and paralog boundary

RPL36AL is an autosomal, expressed retrocopy of the X-linked RPL36A gene. The
gene-discovery study found that RPL36AL is ubiquitously expressed
PMID:12490704. The fetched reviewed
UniProt sequences are each 106 residues long and differ only at residue 38:
RPL36A has lysine and RPL36AL has arginine. The proteins are therefore much
harder to distinguish than the genes, especially in untargeted proteomics.

This review transfers no RPL36A-specific muscle, cancer, localization, or
interaction annotations to RPL36AL. Evidence is treated as RPL36AL-specific only
when the paper explicitly identifies the gene product or uses a recombinant
RPL36AL construct. Family-level human eL42 results that do not state an accession
are used only as context.

Direct ribosomal and tRNA evidence

The 2012 crosslinking study explicitly identified RPL36AL as the mammalian
large-subunit protein contacting P/E-state tRNA. It mapped the contact to the
CCA-end and RPL36AL Lys53 PMID:22865768.

The 2014 follow-up used purified recombinant human RPL36AL and human 80S
ribosomes. Surface-plasmon-resonance measurements gave nanomolar affinities for
full-length and truncated tRNAs, while poly(A) and poly(U) controls did not bind
PMID:25191528. The same paper
recovered RPL36AL-tRNA contacts in assembled ribosomes. This directly supports a
NEW tRNA binding annotation (GO:0000049) in addition to the established
structural constituent of ribosome function.

The paper also explored possible peptidyl-tRNA hydrolase activity and translation
termination geometry. Those observations were not converted into independent GO
annotations because they do not establish a physiological catalytic activity of
free RPL36AL. Similarly, the 2024 conserved-motif paper supports a role for human
eL42 in E-site tRNA release, but its abstract does not identify which of the
single-residue RPL36A/RPL36AL paralogs supplied the FLAG-tagged construct.

Existing annotation decisions

GO annotation Decision Rationale
cytoplasmic translation, IBA ACCEPT Core process of a cytosolic 60S protein, reinforced by direct human-ribosome evidence.
structural constituent of ribosome, IBA ACCEPT Core molecular function supported by family, complex, and biochemical evidence.
cytosolic large ribosomal subunit, IBA ACCEPT Most specific established complex membership.
structural constituent of ribosome, IEA ACCEPT Correct InterPro mapping and action-consistent with the IBA record.
cytoplasm, IEA ACCEPT Correct broad functional localization.
ribosome, IEA ACCEPT Correct broad complex term.
translation, IEA ACCEPT Correct broad process term.
protein binding, IPI MARK_AS_OVER_ANNOTATED The KRTAP10-7 screen hit is retained as interaction data, but generic protein binding is not an informative function.
nucleus, IDA UNDECIDED The candidate-level localization is confined to an inaccessible supplementary table; the accessible narrative does not name RPL36AL.

The defensible core is a cytosolic 60S-subunit structural role coupled to direct
tRNA binding.

New annotation

Open questions