ARL16 notes

• RIG-I inhibitor PMID:21233210, human cells:
• GTP-bound ARL16 binds the RIG-I CTD and blocks RNA binding.
• Knockdown potentiates virus-induced IFN-beta.
• Cilia PMID:35196065:
• Endogenous ARL16 sits along the ciliary axoneme in human RPE1 cells, plus cytosol and mitochondria (HSP60).
• In human retina it is in the photoreceptor ciliary region and inner segment.
• Arl16 knockout MEFs: fewer but longer cilia; IFT140 and INPP5E stuck at the Golgi.
• Atypical G-3 motif PMID:38606629.

GOA calls

• Protein binding (30 rows) → REMOVE. These are Y2H screens (neurodegeneration map, HuRI, HI-II-14) plus RIG-I. The RIG-I biology moves to a NEW BP row.
• ACCEPT: GTP binding, axoneme, cytoplasm.
• UNDECIDED: GTPase activity (atypical G-3; no hydrolysis measured).
• Non-core: mitochondrion, photoreceptor inner segment.
• NEW:
• Negative regulation of RIG-I signaling pathway (IMP, human).
• Protein localization to cilium (ISO from mouse Arl16, MGI:1917567).

Review round 1 (PR #4178)

• NEW ciliary basal body (IDA, PMID:35196065), from the photoreceptor centrin 3 co-staining; UniProt records this location but GOA lacks it. Added as a core-function location.
• GTP binding now quotes the radiolabelled-GTP binding assay and the T37N / delta45-54 GTP-free mutants (PMID:21233210).
• Cytoplasm rows now quote only the diffuse cytosolic staining.
• Mitochondrion row notes the authors' attribution to a longer ARL16 variant.
• ISO donor MGI:1917567 verified as mouse Arl16 (UniProt B1ATY8).

2026-10-24 ORGANELLES batch 2 (mitochondrion rows)

• Rows: GO:0005739 EXP (PMID:35196065) and IEA (GO_REF:0000044, SL-0173). Both stay KEEP_AS_NON_CORE; reasons now record the check.
• EXP is direct (rule 2). Endogenous ARL16 co-stains with HSP60 PMID:35196065. The expressed long variant is mitochondrial PMID:35196065. The assay resolves the organelle only.
• IEA: SL-0173 carries ECO:0000269 from PMID:35196065 in UniProt, so the mapping is sound.
• Rule 4: stays at the root because there is only one weak line. The canonical 173-residue chain has no presequence or TM. The mitochondrial signal is attributed to an N-terminally extended variant that UniProt lists only under a sequence caution ("Erroneous initiation; Note=Extended N-terminus"). Whether that extension is a presequence is untested, and there is no fractionation.
• Outcome: root.