# PN dossier: LTN1

- review_batch: proteostasis-batch-2026-06-07c
- review_yaml: genes/human/LTN1/LTN1-ai-review.yaml
- PN workbook rows: 3

## PN row 1: Translation | Cytosolic translation | Ribosome-associated QC | Ubiquitination
- UniProt: O94822
- In branches: TR, UPS
- PN-node mapping records (path + ancestors):
    - [type] Translation|Cytosolic translation|Ribosome-associated QC|Ubiquitination
        status=mapped scope=ok_for_propagation_to_go GO=[GO:0016567 protein ubiquitination]
        rationale: This PN RQC type denotes ubiquitination events on stalled translation complexes. Protein ubiquitination is the shared process target.
    - [group] Translation|Cytosolic translation|Ribosome-associated QC
        status=mapped scope=ok_for_propagation_to_go GO=[GO:0006515 protein quality control for misfolded or incompletely synthesized proteins]
        rationale: The PN ribosome-associated quality-control group covers surveillance and disposal of stalled or defective nascent-chain translation products. GO lacks a dedicated ribosome-associated QC term in the local cache, so the broader protein-quality-control process is the best supported target.
    - [class] Translation|Cytosolic translation
        status=context_only scope=too_broad_to_propagate GO=[GO:0002181 cytoplasmic translation]
        rationale: The PN class Cytosolic translation is centered on the cytoplasmic translation apparatus and process, but it also houses supporting machinery such as ribosome biogenesis factors. The GO process term is a useful high-level label for the class, but propagating it to all members would over-annotate genes whose PN placement is through assembly or maturation context rather than core cytoplasmic translation.
    - [branch] Translation
        status=context_only scope=too_broad_to_propagate GO=[GO:0006412 translation]
        rationale: The PN Translation branch is organized around the translation apparatus and immediately associated cotranslational quality-control systems. GO translation is the closest high-level process label, but the PN branch also contains adjacent machinery such as ribosome biogenesis and nascent-chain handling. Keeping this relationship is useful for interpretation, but it is too broad to project safely onto every member.

## PN row 2: Ubiquitin Proteasome System | E3 ubiquitin and UBL ligases | RING | ubiquitin binding domain | Armadillo-like
- UniProt: O94822
- In branches: TR, UPS
- Signature domains: IPR001841
- Auxiliary domains: IPR011989
- PN references (titles):
    - 19489725 / rev
- PN-node mapping records (path + ancestors):
    - [subtype] Ubiquitin Proteasome System|E3 ubiquitin and UBL ligases|RING|ubiquitin binding domain|Armadillo-like
        status=no_mapping scope= GO=[]
        rationale: Reviewed as a narrower E3-ligase architecture, component, or domain subdivision already covered by the curated parent E3 mapping. No additional direct GO mapping is needed at this node.
    - [type] Ubiquitin Proteasome System|E3 ubiquitin and UBL ligases|RING|ubiquitin binding domain
        status=no_mapping scope= GO=[]
        rationale: Reviewed as a narrower E3-ligase architecture, component, or domain subdivision already covered by the curated parent E3 mapping. No additional direct GO mapping is needed at this node.
    - [group] Ubiquitin Proteasome System|E3 ubiquitin and UBL ligases|RING
        status=mapped scope=ok_for_propagation_to_go GO=[GO:0061630 ubiquitin protein ligase activity]
        rationale: This PN group is a catalytic ubiquitin E3 ligase bucket. The shared GO molecular-function target is ubiquitin protein ligase activity.
    - [class] Ubiquitin Proteasome System|E3 ubiquitin and UBL ligases
        status=context_only scope=too_broad_to_propagate GO=[GO:0061630 ubiquitin protein ligase activity]
        rationale: This class is a genuine E3-ligase context, but its descendants include catalytic ligases, cullin scaffolds, substrate receptors, adaptors, cofactors, regulators, and UBL modifier systems. A class-level propagation would over-annotate.
    - [branch] Ubiquitin Proteasome System
        status=no_mapping scope= GO=[]
        rationale: Reviewed as the top-level UPS branch. It is a project taxonomy umbrella rather than a direct GO assertion; UPS propagation must come from manually curated child nodes.

## PN row 3: Ubiquitin Proteasome System | Ubiquitin and UBL binding | E3 ligase | RING / with UBD | RWD (LTN1)
- UniProt: O94822
- In branches: TR, UPS
- Signature domains: IPR054478
- Auxiliary domains: IPR001841
- PN-node mapping records (path + ancestors):
    - [subtype] Ubiquitin Proteasome System|Ubiquitin and UBL binding|E3 ligase|RING / with UBD|RWD (LTN1)
        status=no_mapping scope= GO=[]
        rationale: Reviewed as a narrower enzyme-family, domain, or architecture subdivision already covered by a curated parent enzyme mapping. No additional direct GO mapping is needed at this node.
    - [type] Ubiquitin Proteasome System|Ubiquitin and UBL binding|E3 ligase|RING / with UBD
        status=no_mapping scope= GO=[]
        rationale: Reviewed as a narrower enzyme-family, domain, or architecture subdivision already covered by a curated parent enzyme mapping. No additional direct GO mapping is needed at this node.
    - [group] Ubiquitin Proteasome System|Ubiquitin and UBL binding|E3 ligase
        status=mapped scope=ok_for_propagation_to_go GO=[GO:0061630 ubiquitin protein ligase activity]
        rationale: This PN group captures ubiquitin/UBL-binding factors that are E3 ligases. The shared molecular-function target is ubiquitin protein ligase activity.
    - [class] Ubiquitin Proteasome System|Ubiquitin and UBL binding
        status=context_only scope=too_broad_to_propagate GO=[GO:0140036 ubiquitin-modified protein reader activity]
        rationale: This class records ubiquitin/UBL-reader context, but the subtree mixes ubiquitin, SUMO, UBL-domain, domain-architecture, catalytic, signaling, trafficking, and nucleic-acid process buckets. It is useful context, not a safe direct propagation.
    - [branch] Ubiquitin Proteasome System
        status=no_mapping scope= GO=[]
        rationale: Reviewed as the top-level UPS branch. It is a project taxonomy umbrella rather than a direct GO assertion; UPS propagation must come from manually curated child nodes.

## Projected GO annotations (4)
- GO:0006515 protein quality control for misfolded or incompletely synthesized proteins | scope=ok_for_propagation_to_go | goa_status=new_to_goa | from=Translation|Cytosolic translation|Ribosome-associated QC
- GO:0016567 protein ubiquitination | scope=ok_for_propagation_to_go | goa_status=already_in_goa_exact | from=Translation|Cytosolic translation|Ribosome-associated QC|Ubiquitination
- GO:0061630 ubiquitin protein ligase activity | scope=ok_for_propagation_to_go | goa_status=already_in_goa_exact | from=Ubiquitin Proteasome System|E3 ubiquitin and UBL ligases|RING
- GO:0061630 ubiquitin protein ligase activity | scope=ok_for_propagation_to_go | goa_status=already_in_goa_exact | from=Ubiquitin Proteasome System|Ubiquitin and UBL binding|E3 ligase