pen-2 (Drosophila melanogaster, Q86BE9) notes

Identity

• Small two-TM hairpin subunit of gamma-secretase; required for presenilin endoproteolysis and activation of the complex.

Literature

• PMID:12110170
• PMID:12660785; PMID:12660785.
• PMID:20421416.

Curation thoughts

• Activator role: positive regulation of endopeptidase activity (IMP) accepted; endopeptidase activator activity (GO:0061133, as for human PSENEN) used as core MF.
• Shared gamma-secretase terms treated as for Nct and aph-1.

2026-10-12: why core_functions asserts no location

• The core location is given by in_complex: GO:0070765 gamma-secretase complex, which is part_of membrane. The two generic membrane rows are MODIFY'd to that complex.
• pen-2 has no plasma membrane annotation. Its compartment annotations are late endosome and recycling endosome (IDA, PMID:20421416). They are kept as non-core because gamma-secretase is spread across the plasma membrane and endolysosomal compartments, and no single compartment defines it. So no location is asserted, consistent with aph-1.