## SPCS3
- **UniProt:** P61009 · **batch:** proteostasis-batch-2026-06-11 · **review status:** COMPLETE
- **PN placement:** `ER proteostasis|Protein transport|ER signal peptidase` ; **PN-node mapping:** group=mapped/ok_for_propagation_to_go GO:0005787 signal peptidase complex; parent class "Protein transport"=mapped/ok GO:0015031 protein transport; branch=no_mapping.
- **Consistency:** Deep research (notes + falcon) ↔ review YAML ↔ PN annotation are consistent. All four describe SPCS3 as a non-catalytic accessory subunit of the ER signal peptidase complex (SPC-A/SPC-C), essential for SEC11 catalytic activity, single-pass type II ER membrane protein, plus a secondary flavivirus host-factor role. No contradictions. The PN "ER signal peptidase" group→GO:0005787 matches the review's CORE annotation exactly.
- **PN story / NEW pressure:** The PN group mapping (signal peptidase complex, GO:0005787) is already a CORE GOA/review annotation — already captured, no NEW pressure. The review's preferred process term GO:0006465 signal peptide processing (proposed replacement for the IBA GO:0045047) is already a standard term, also no NEW term needed.
- **Mapping strategy:** Concern — the parent **class** node "ER proteostasis|Protein transport" projects **GO:0015031 protein transport** as `new_to_goa` to SPCS3. SPCS3 does NOT mediate protein transport; it is a signal peptidase accessory subunit acting downstream of translocation (the review explicitly MODIFIES the IBA "protein targeting to ER" to "signal peptide processing"). GO:0015031 over-reaches here, analogous to the TOMM20/HSPA8/RAB7A "broader" rejections. The group-level GO:0005787 mapping is correct; the class-level GO:0015031 projection should not be propagated to SPCS3.
- **Evidence alignment:** Strong overlap. PN reference titles (cryo-EM SPC structure; flavivirus CRISPR screen) match review PMID:34388369 and PMID:27383988. Review adds breadth (CHIKV PMID:39261662, HCV PMID:38230952, ComplexPortal/Reactome) beyond the PN row.
- **Verdict:** Internally consistent and well-curated. Recommend NOT propagating the class-level GO:0015031 protein transport to SPCS3 (over-reach); GO:0005787 is correctly captured.