### CAPN2 Gene Overview

**Gene Symbol**: CAPN2  
**Function**: The CAPN2 gene encodes for the large subunit of calpain 2, a calcium-activated neutral protease involved in various cellular processes such as cytoskeletal remodeling, signal transduction, and protein degradation. 

#### 1. Associated Genes
CAPN2 is known to interact with various genes and proteins involved in cellular signaling pathways and cytoskeletal dynamics. Some notable associates include:

- **MYOC (myocilin)**: CALP2 cleaves MYOC, which is involved in the regulation of intraocular pressure and ocular development.
- **CPEB3 (cytoplasmic polyadenylation element-binding protein 3)**: CAPN2 modulates CPEB3 activity following neuronal stimulation, implicating it in synaptic plasticity and memory.
- Other calpain family members: CAPN1 and CAPN3 are other calpain isoforms that may interact with pathways regulated by CAPN2.
- **GSK3B (Glycogen synthase kinase 3 beta)**: Interplays with signaling adaptations as part of the Wnt pathway, which is also influenced by calpain activity.

#### 2. Aging and Age-Related Diseases
Research indicates that dysregulation of CAPN2 may be linked to various age-related conditions:

- **Neurodegenerative Diseases**: Calpains, including CAPN2, have been implicated in the pathology of Alzheimer’s disease, where abnormal proteolysis contributes to tau hyperphosphorylation and amyloid-beta accumulation.
- **Sarcopenia**: The role of CAPN2 in muscle proteolysis links it to sarcopenia and muscle decline associated with aging.
- **Cardiovascular Diseases**: Altered calpain activity may contribute to cardiac remodeling and dysfunction in the elderly, particularly following myocardial infarction.

#### 3. Drug Interactions
While specific drugs that target CAPN2 directly may not be extensively documented, calpain inhibitors are noteworthy: 

- **Calpain Inhibitors**: Such as calpeptin and ALLM (N-acetyl-leu-leu-methioninal), are used in research settings to inhibit calpain activity and study its role in pathological conditions.
- **Drug Classes**: Calcium channel blockers may indirectly affect CAPN2 by altering calcium availability, which is essential for calpain activation.

#### 4. Pathways and Biological Processes
CAPN2 is involved in various biological pathways and processes, including:

- **Calcium signaling**: As a calcium-dependent protease, CAPN2 functions in pathways that are influenced by intracellular calcium levels.
- **Cellular stress responses**: Involved in apoptosis and necrosis processes, CAPN2 mediates cellular responses to stress, such as oxidative stress.
- **Neurotransmitter release and synaptic function**: CAPN2 is implicated in neuronal plasticity, regulating mRNA translation during synaptic activity.
- **Inflammatory responses**: Participation in signaling cascades that modulate inflammation via the proteolytic cleavage of signaling molecules.

### Conclusion
The CAPN2 gene plays a critical role in various physiological and pathological processes, linking it to cellular signaling, muscle function, neurobiology, and age-related health problems. Its interactions with multiple genes and involvement in different pathways further enhance its significance in biological research and potential therapeutic interventions.