Pen2 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
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| Attribute |
Value |
| Gene Symbol |
PSENEN |
| Gene Name |
Presenilin Enhancer 2 |
| Official Full Name |
Presenilin Enhancer, Gamma-Secretase Subunit |
| Chromosomal Location |
19q13.12 |
| GRCh38 Coordinates |
chr19:36,462,519-36,464,099 |
| NCBI Gene ID |
55127 |
| OMIM ID |
607632 |
| Ensembl ID |
ENSG00000129121 |
| UniProt ID |
Q9BYH1 |
| Gene Family |
Gamma-secretase complex |
-}}
The PSENEN gene (also called PEN2) encodes a critical component of the gamma-secretase complex, an intramembrane protease responsible for cleaving a wide range of substrates including the Amyloid Precursor Protein (APP).[1] Gamma-secretase generates amyloid-beta (Aβ) peptides from APP, and alterations in its activity are central to Alzheimer's disease pathogenesis.
PEN2 is an essential accessory subunit of the gamma-secretase complex, which consists of four core components:
| Subunit |
Gene |
Function |
| Presenilin |
PSEN1/PSEN2 |
Catalytic aspartyl protease |
| Nicastrin |
NCSTN |
Substrate recognition |
| APH-1 |
APH1A/APH1B |
Stabilizes complex |
| PEN2 |
PSENEN |
Required for endoproteolysis of presenilin |
- Gamma-secretase performs regulated intramembrane proteolysis (RIP)
- Cleaves within the transmembrane domain of substrates
- Generates Aβ peptides of varying lengths (Aβ40, Aβ42, Aβ43)
- Processes Notch, providing critical developmental signals
- APP processing: Generates amyloid-beta peptides
- Notch signaling: Essential for development and cell fate
- Cell adhesion: Processescadherins and other adhesion molecules
- Signal transduction: Processes various receptor tyrosine kinases
PEN2 is directly implicated in AD pathogenesis through its role in Aβ production:
- Gain of function: Increased gamma-secretase activity leads to elevated Aβ42 production
- Aβ42/Aβ40 ratio: Shift toward more aggregation-prone Aβ42
- Familial AD: Mutations in other gamma-secretase components (PSEN1, PSEN2) cause early-onset FAD
- Gamma-secretase processes Notch, affecting cell proliferation
- PEN2 expression altered in various cancers
- Potential therapeutic target
- Notch signaling disorders: Developmental abnormalities
- Cardiovascular disease: Gamma-secretase in vascular biology
| Variant |
Effect |
Clinical Significance |
| c.80G>A (p.R27Q) |
Missense |
Possibly alters gamma-secretase activity |
| c.92C>T (p.S31L) |
Missense |
Rare variant of uncertain significance |
| Promoter variants |
Altered expression |
May affect AD risk |
- Tissue Distribution: Ubiquitously expressed; highest in brain, heart, kidney
- Brain Expression: Neurons, astrocytes, microglia
- Cellular Localization: Endoplasmic reticulum, Golgi, plasma membrane
- Subcellular: Integral membrane protein, localizes to membrane fractions
PEN2 interacts with:
- PSEN1 - Catalytic subunit of gamma-secretase
- PSEN2 - Alternative catalytic subunit
- NCSTN - Nicastrin
- APH1A/APH1B - Aph-1 subunits
- APP - Substrate
- Notch - Substrate
- CADHERIN - Substrate
Gamma-secretase is a major AD drug target:
- Inhibitors: Broad-spectrum inhibitors (semaglintat, avagacestat) - discontinued due to side effects
- Modulators: Shift Aβ production toward shorter, less toxic peptides
- Notch-sparing inhibitors: Target APP processing while sparing Notch
- Indirect modulators: Target upstream APP trafficking
- Structure determination: Cryo-EM structures of gamma-secretase
- Selectivity: Developing substrate-selective inhibitors
- Biomarkers: Gamma-secretase activity as biomarker
- Gene therapy: Modulating gamma-secretase expression
- De Strooper B. "Loss-of-function presenilin mutations in Alzheimer disease." Proc Natl Acad Sci USA. 2003;100(20):11142-11144.
- Takasugi N, et al. "The role of PEN2 in gamma-secretase activity." J Biol Chem. 2003;278(20):18664-18670.
- Wolfe MS. "Gamma-secretase as a therapeutic target for Alzheimer's disease." Mol Neurodegener. 2010;5:25.
- Bai XC, et al. "An atomic structure of human gamma-secretase." Nature. 2015;525(7568):212-217.
- Zhang S, et al. "Targeting gamma-secretase in Alzheimer's disease." Nat Rev Drug Discov. 2020;19(10):651-652.
The study of Pen2 Gene has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- De Strooper B. "Loss-of-function presenilin mutations in Alzheimer disease." Proc Natl Acad Sci USA. 2003;100(20):11142-11144. PMID:14514886
- Takasugi N, et al. "The role of PEN2 in gamma-secretase activity." J Biol Chem. 2003;278(20):18664-18670. PMID:12672818
- Wolfe MS. "Gamma-secretase as a therapeutic target for Alzheimer's disease." Mol Neurodegener. 2010;5:25. PMID:20561331
- Bai XC, et al. "An atomic structure of human gamma-secretase." Nature. 2015;525(7568):212-217. PMID:26255339
- Zhang S, et al. "Targeting gamma-secretase in Alzheimer's disease." Nat Rev Drug Discov. 2020;19(10):651-652. PMID:32661447
Last updated: March 2026