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🔬general biology i review

XPF

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

XPF, or Xeroderma Pigmentosum group F, is a crucial protein involved in the nucleotide excision repair (NER) pathway of DNA repair. It plays a vital role in removing damaged DNA caused by ultraviolet (UV) light and other environmental factors, helping maintain genomic stability. By functioning as a DNA damage recognition factor, XPF assists in the repair process, preventing mutations that could lead to various diseases, including cancer.

5 Must Know Facts For Your Next Test

  1. XPF forms a heterodimer with another protein called ERCC1, which is essential for its stability and function in the DNA repair process.
  2. Mutations in the XPF gene can lead to Xeroderma Pigmentosum, a condition characterized by extreme sensitivity to UV light and a high risk of skin cancers.
  3. XPF specifically incises damaged DNA strands at sites of lesions, allowing for the removal of the damaged segment.
  4. The action of XPF is part of a larger coordinated response involving several proteins that work together to ensure effective DNA repair.
  5. Research shows that XPF is also involved in interstrand cross-link repair, highlighting its importance beyond just UV-induced damage.

Review Questions

  • How does XPF contribute to the nucleotide excision repair pathway?
    • XPF contributes to the nucleotide excision repair pathway by recognizing and incising damaged DNA segments, allowing for their removal. This action is essential in maintaining genomic stability, as it prevents mutations that can arise from unrepaired DNA damage. By working closely with ERCC1, XPF ensures the effective and efficient repair of lesions caused by environmental factors such as UV radiation.
  • What are the implications of mutations in the XPF gene on human health?
    • Mutations in the XPF gene can lead to Xeroderma Pigmentosum, which results in extreme sensitivity to UV light and a significantly increased risk of developing skin cancers. This condition demonstrates how crucial XPF is for DNA repair and highlights the potential consequences when this protein malfunctions. Individuals with this mutation must take stringent precautions to avoid sun exposure due to their heightened vulnerability.
  • Evaluate the broader impact of XPF on cellular health and its potential role in cancer prevention.
    • XPF plays a critical role in cellular health by facilitating the repair of UV-induced DNA damage, thereby reducing the likelihood of mutations that could lead to cancer. Its function in both nucleotide excision repair and interstrand cross-link repair underscores its importance in safeguarding genomic integrity. By preventing these mutations, XPF can help reduce cancer incidence, illustrating how essential proper DNA repair mechanisms are for overall cellular function and longevity.