Xpc-rad23b complex

Definition

The xpc-rad23b complex is a protein assembly that plays a crucial role in the recognition and repair of DNA damage, specifically in nucleotide excision repair (NER). This complex identifies DNA lesions caused by environmental factors like UV light, ensuring that the integrity of the genome is maintained by initiating the repair process. The proper functioning of this complex is essential for cellular health and prevention of mutations that could lead to diseases such as cancer.

5 Must Know Facts For Your Next Test

1. The xpc-rad23b complex specifically recognizes helix-distorting DNA damage, such as thymine dimers formed from UV exposure.
2. This complex is formed by the XPC protein and RAD23B, which work together to initiate the repair process by recruiting other proteins involved in NER.
3. Defects in the xpc-rad23b complex can lead to impaired DNA repair, resulting in increased susceptibility to DNA damage and related diseases.
4. In addition to its role in NER, the xpc-rad23b complex is also involved in maintaining genome stability by participating in transcription-coupled repair mechanisms.
5. The proper functioning of the xpc-rad23b complex is vital for preventing mutations that could contribute to cancer development and progression.

Review Questions

• How does the xpc-rad23b complex contribute to nucleotide excision repair and what specific type of DNA damage does it recognize?
  • The xpc-rad23b complex plays a pivotal role in nucleotide excision repair by recognizing helix-distorting DNA damage such as thymine dimers formed from UV radiation. Once this damage is identified, the complex recruits additional proteins necessary for the repair process. This recognition and recruitment are essential for ensuring that DNA integrity is maintained, preventing mutations that could lead to serious cellular consequences.
• Discuss the implications of defects in the xpc-rad23b complex on human health, particularly regarding cancer risk.
  • Defects in the xpc-rad23b complex severely impair the body's ability to repair DNA damage, particularly from environmental sources like UV light. Individuals with such defects are at an increased risk for developing conditions such as Xeroderma Pigmentosum, which leads to heightened sensitivity to UV rays and a significantly elevated risk of skin cancers. This relationship highlights how critical effective DNA repair mechanisms are for maintaining genomic stability and preventing cancer.
• Evaluate the role of the xpc-rad23b complex within the broader context of DNA damage response mechanisms in cells.
  • The xpc-rad23b complex is integral to the broader DNA damage response mechanisms within cells, working specifically in nucleotide excision repair to address various forms of DNA lesions. By participating in this essential repair pathway, it not only helps maintain genomic integrity but also interacts with other DNA repair systems, such as transcription-coupled repair. This interconnectedness emphasizes how vital efficient DNA repair systems are to cellular health and how disruptions can lead to a cascade of genomic instability and disease.

Related terms

Nucleotide Excision Repair (NER): A DNA repair mechanism that removes bulky DNA adducts and other lesions, restoring the normal structure of the DNA strand.

DNA Damage Response (DDR): A series of cellular processes that detect and repair damaged DNA, preventing the propagation of mutations.

Xeroderma Pigmentosum: A genetic disorder caused by mutations in genes responsible for NER, leading to extreme sensitivity to UV radiation and a higher risk of skin cancers.