### Overview of the SKP2 Gene

**Gene Symbol**: SKP2  
**Location**: Chromosome 5q31  
**Function**: The SKP2 gene encodes an F-box protein that serves a critical role in the ubiquitin-proteasome system, particularly through its function as a substrate recognition component of the SCF (SKP1-CUL1-F-box protein) E3 ubiquitin ligase complex. This complex mediates the ubiquitination and degradation of various target proteins involved in cell cycle progression, transcription regulation, and signal transduction.

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### 1. Associated Genes with SKP2

In addition to the genes mentioned in the summaries provided, SKP2 is linked to several other genes important for various cellular processes, including:

- **CDK1** (Cyclin-dependent kinase 1)
- **CycE1** (Cyclin E1)
- **RBL1** (Retinoblastoma-like 1)
- **E2F1** (Transcription factor E2F1)
- **MYC** (Myelocytomatosis oncogene)
- **KLF4** (Kruppel-like factor 4)
- **FBXW7** (F-box and WD repeat domain containing 7)
- **BRCA1** (Breast cancer 1)
- **PTEN** (Phosphatase and tensin homolog)

These associations further situate SKP2 within a broad regulatory network impacting cell proliferation and survival.

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### 2. Aging and Age-related Diseases

The SKP2 gene has implications in aging and age-associated diseases, particularly due to its role in regulating the cell cycle and apoptosis. Here are some pertinent details:

- **Cellular Senescence**: SKP2 has been implicated in the regulation of cellular senescence, with overexpression leading to bypass of senescence checkpoints, which can contribute to tumorigenesis. 
- **Cancer**: SKP2 is recognized as a proto-oncogene and has been associated with various cancers, including lymphomas and solid tumors. Its dysregulation can promote cell cycle progression and prevent apoptosis, which are hallmarks of cancer progression.
- **Age-Related Decline**: Dysregulation of proteolytic pathways involving SKP2 may be tied to age-related degeneration and the increased incidence of age-related diseases, including neurodegenerative conditions and metabolic syndromes.

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### 3. Drugs and Drug Classes Interacting with SKP2

While specific drugs targeting SKP2 directly may not be widely used, certain classes of drugs may interact indirectly with the signaling pathways related to SKP2 or influence its activity:

- **Proteasome Inhibitors**: Drugs like Bortezomib and Carfilzomib inhibit proteasome function, which may affect SKP2's role in regulating protein degradation.
- **CDK Inhibitors**: Drugs targeting cyclin-dependent kinases (e.g., Palbociclib, Ribociclib), which SKP2 influences through targeting proteins like CDKN1B, may alter SKP2-related pathways.
- **Antineoplastic Agents**: Many chemotherapeutics target cell cycle regulators and may consequently impact the activity of SKP2 through various mechanisms.

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### 4. Pathways and Biological Processes Involved

The SKP2 gene is involved in several key biological processes and pathways:

- **Ubiquitin-mediated proteolysis**: As part of the SCF E3 ligase complex, SKP2 participates in the ubiquitination of substrates for proteasomal degradation.
- **Cell Cycle Regulation**: SKP2 plays an essential role in the transition from G1 to S phase by targeting CDK inhibitors, particularly CDKN1B/p27.
- **Signal Transduction**: By regulating target proteins, SKP2 mediates various signaling pathways related to growth factor signaling, hormonal regulation, and stress responses.
- **Transcription Regulation**: SKP2's interactions can influence transcriptional activity through its effect on transcription factors like E2F1 and MYC.
- **Apoptosis**: By regulating proteins involved in the apoptotic pathways, SKP2 may influence cell survival and cancer development.

In summary, SKP2 is a crucial gene involved in intricate networks regulating cell cycle, signaling, and protein degradation, with significant implications for oncogenesis and potentially age-related diseases.