Mitochondrion targeting sequence binding: obsoletion

GO:0030943 → GO:0140436 mitochondrial signal sequence receptor activity, row by row

AI Gene Review · projects/MITOCHONDRION_TARGETING_SEQUENCE_BINDING_OBSOLETION · 2026

Bottom line

  • GO obsoleted GO:0030943; the receptor term the project waited for now exists as GO:0140436 (OLS, 2026-09-26).
  • Only some of the 18 curated rows are true presequence receptors (TOM20/22, likely TIM50); channels, a plant protein and the TIM23 complex need individual calls.
  • 10 reviews here touch the old term, 5 in core_functions. Remapping done in #3234: receptors → GO:0140436, channels TOMM40 and TIM22 → GO:0008320.

Old term → replacement, by class

Receptors versus channels

Why no blanket replaced_by

  • TOM20 / TOM22 read the amphipathic presequence on the cytosolic face: a receptor, a clean fit.
  • TIM50 hands the presequence to TIM23 in the intermembrane space: receptor-like.
  • TIM23 is the channel: receptor MF, or a transporter feeding the import process?
  • TIM22 imports carriers with internal signals, not presequences.
  • PAP2 (Arabidopsis, IPI) and the TIM23 complex records need case-by-case calls.
  • About 12,091 IEA/IBA rows sit on the term; pipelines will need reseeding.

The 10 reviews that touch GO:0030943: before and after #3234

Review Rows on GO:0030943 Before After #3234
human TOMM20 IDA, IBA; replacement target ACCEPT MODIFY → GO:0140436
human TOMM22 IDA ACCEPT MODIFY → GO:0140436
human TOMM70 IBA, ISS ACCEPT MODIFY → GO:0140436
human TIMM50 NAS NEW NEW on GO:0140436
worm tomm-22 ISS NEW NEW on GO:0140436
yeast TOM22 none (core MF) NEW on GO:0140436
human TOMM40 IBA ACCEPT MODIFY → GO:0008320
yeast TIM22 IDA, IBA ACCEPT MODIFY → GO:0008320
human TIMM22 IBA MARK_AS_OVER_ANNOTATED MODIFY → GO:0008320
yeast ACL4 IBA UNDECIDED UNDECIDED, no replacement

Core MFs of TOMM20, TOMM22, TIMM50, tomm-22 and TOM22 now use GO:0140436.

Status and next steps

  • 2026-05-28: project created; the replacement term was not yet in OLS.
  • 2026-09-26: GO:0030943 obsolete, GO:0140436 live. Local cache/ontologies/go.tsv still lists the old term as live, so validation is quiet.
  • #3234: MODIFY pass across all ten reviews: receptors → GO:0140436, channels → GO:0008320, ACL4 left UNDECIDED.
  • Next: upstream PAP2 and TIM23-complex rows are for GO curators.
  • Coordinate with the MITOCHONDRIAL_IMPORT_PATHWAYS project.

Upstream: go-annotation#6437 · go-ontology#32142 · #31711
Read more: projects/MITOCHONDRION_TARGETING_SEQUENCE_BINDING_OBSOLETION.md