PELO (Pelota homolog / Dom34) — research notes

UniProt: Q9BRX2. Member of the eukaryotic release factor 1 (eRF1) family, Pelota subfamily. 385 aa, cytoplasmic.

Core function

PELO is the eRF1-like component of the Pelota-HBS1L (Dom34-Hbs1) complex, a ribosome-rescue
machine. Unlike eRF1, it has no peptidyl-tRNA hydrolase (peptide release) activity; it instead
recognizes ribosomes stalled at the 3' end of an mRNA (truncated/non-stop, no-go) and, together
with the GTPase HBS1L and the recycling ATPase ABCE1, drives subunit dissociation (ribosome
disassembly), initiating No-Go Decay (NGD) and Non-Stop Decay (NSD).

• [file:human/PELO/PELO-uniprot.txt "Component of the Pelota-HBS1L complex, a complex that recognizes stalled ribosomes and triggers the No-Go Decay (NGD) pathway"]
• [file:human/PELO/PELO-uniprot.txt "In the Pelota-HBS1L complex, PELO recognizes ribosomes stalled at the 3' end of an mRNA and engages stalled ribosomes by destabilizing mRNA in the mRNA channel"]
• [file:human/PELO/PELO-uniprot.txt "Belongs to the eukaryotic release factor 1 family. Pelota subfamily."]
• PMID:21448132 — biochemical reconstitution of subunit dissociation (ribosome disassembly).
• PMID:27863242 — cryo-EM of the PELO-HBS1L complex on stalled ribosomes; defines stalled-ribosome sensor activity, ribosome binding, Dom34-Hbs1 complex.
• PMID:23667253 — NSD/no-go decay role.
• PMID:27543824 — K2A/R45A mutants abolish rescue of stalled ribosomes (UniProt MUTAGEN).

Other / non-core

• PINK1-regulated mitophagy: upon mitochondrial damage PELO is recruited to mito-OM-associated ribosome/mRNP, enabling autophagy receptor recruitment PMID:29861391. Peripheral, context-specific.
• Many IntAct protein binding IPI rows are high-throughput interactors (HSPB1, HTT, FLNA, etc.); HBS1L (Q9Y450) and EIF3G/ABCE1 are the biologically meaningful ones. Bare GO:0005515 is uninformative.
• Ensembl IEA developmental terms (endoderm development, inner cell mass proliferation, BMP signaling, stem cell maintenance) reflect mouse Pelo knockout phenotypes (embryonic lethality) — downstream/pleiotropic, not in GOA TSV here.

Action plan

• Core MF: GO:0170011 stalled ribosome sensor activity; GO:0043022 ribosome binding. Core BP: GO:0072344 rescue of stalled cytosolic ribosome; GO:0032790 ribosome disassembly. Core CC: GO:1990533 Dom34-Hbs1 complex.
• NGD/NSD BP (GO:0070966, GO:0070481) accept/keep.
• Bare protein binding IPI → KEEP_AS_NON_CORE (HBS1L) or MARK_AS_OVER_ANNOTATED (random HT hits).