### ACTR3 Gene Overview

**Gene Symbol:** ACTR3  
**Location:** The ACTR3 gene is located on human chromosome 17.

**Function:** ACTR3 encodes a protein that is a core component of the ARP2/3 complex, which is critical for actin filament nucleation, leading to the formation of branched actin networks. This function is vital for cellular processes such as motility, shape maintenance, and cellular architecture. The Arp2/3 complex is particularly important in lamellipodia formation, which is crucial for the movement of cells, as well as in processes occurring within the nucleus where it regulates gene transcription and DNA repair.

### Associated Genes

While there are several genes associated with the function of ACTR3, not explicitly mentioned in the provided summaries are:

- **ARPC1A**: Arp2/3 complex subunit, involved in stabilizing the complex.
- **ARPC5**: Another subunit of the ARP2/3 complex.
- **WAVE1 / WAVE2 (\*WASH)**: Nucleation-promoting factors that facilitate the activation of ARP2/3.
- **NEDD4**: A ubiquitin ligase that has been suggested to have an indirect connection with actin dynamics and motility through interaction with components related to ACTR3.

### Aging and Age-Related Diseases

1. **Aging**: The role of cytoskeletal dynamics, which ACTR3 is involved in, is crucial in cellular aging. Changes in actin polymerization and filament integrity have been noted with age, affecting cell motility and communication.
   
2. **Age-Related Diseases**: Altered function of the ARP2/3 complex has been implicated in various diseases, including:
   - **Cancer**: Increased motility due to enhanced actin polymerization can facilitate metastasis.
   - **Neurodegenerative Diseases**: Impaired actin dynamics, due in part to dysfunctions in ACTR3 or associated pathways, may underlie aspects of neurological diseases, hinting at the complex's role in neuronal mobility and signaling.
   
3. **Muscle Degeneration**: The role of the cytoskeleton in muscular structure and dynamics means there could be relevance in muscular degeneration diseases as well.

### Drug Interactions

There are currently no specific drugs targeting ACTR3 directly. However, considering its crucial role in actin dynamics, drugs that influence the actin cytoskeleton may indirectly affect the function of ACTR3. Classes of drugs that can influence actin dynamics include:

- **Cytoskeletal inhibitors**: Such as cytochalasins (which block actin polymerization) and latrunculin (which sequesters actin monomers).
- **Nucleation-promoting factor modulators**: Investigational drugs that target pathways involving ARP2/3 activation may influence ACTR3's function.

### Pathways and Biological Processes

ACTR3 is involved in several key biological processes:

1. **Actin Polymerization**: As a part of the ARP2/3 complex, ACTR3 promotes actin filament nucleation and branching.
2. **Cell Motility**: Essential for cell migration and shape, influenced by lamellipodia formation.
3. **Gene Regulation**: In the nucleus, it plays a role in nuclear actin polymerization, influencing transcription and DNA repair mechanisms.
4. **Ciliogenesis**: Contributing to the development and maintenance of cilia in various cell types.
5. **Endocytosis**: Involved in facilitating endocytotic processes through its dynamics with actin structures.

Understanding the complex functions of ACTR3 and its interactions with other components within cellular pathways continues to be a vital area of research, especially in the contexts of development, disease, and therapeutic interventions.