Telomeric repeat-binding factor 2

Telomeric Repeat-binding Factor 2

Diagram of TERF2 domains

Telomeric repeat-binding factor 2 (TERF2) is a crucial protein involved in the maintenance and protection of telomeres, the specialized structures at the ends of chromosomes. TERF2 is part of the shelterin complex, a group of proteins that specifically bind to telomeric DNA and regulate its structure and function.

Structure

TERF2 is characterized by several distinct domains that contribute to its function. The protein contains a Myb domain, which is responsible for binding to the telomeric DNA sequence. Additionally, TERF2 has a TRFH (TERF2 homology) domain that mediates protein-protein interactions, allowing it to recruit other components of the shelterin complex.

Function

The primary role of TERF2 is to protect telomeres from being recognized as sites of DNA damage. It achieves this by facilitating the formation of a T-loop structure, where the single-stranded 3' overhang of the telomere invades the double-stranded region, effectively hiding the chromosome end. This structure prevents the activation of DNA damage response pathways that would otherwise lead to inappropriate repair activities.

TERF2 also plays a role in the recruitment of other proteins to the telomere. It interacts with various client proteins that are involved in telomere maintenance and DNA repair processes.

TERF2 recruitment of client proteins

Role in Telomere Maintenance

TERF2 is essential for the stability and integrity of telomeres. By maintaining the T-loop structure, TERF2 prevents the activation of ATM and ATR kinase pathways, which are typically triggered by DNA double-strand breaks. This protective function is crucial for preventing chromosomal instability and genomic instability, which can lead to cancer and other age-related diseases.

Clinical Significance

Dysfunction of TERF2, whether through mutation or altered expression, can lead to telomere shortening and genomic instability. This has been implicated in various diseases, including cancer and premature aging syndromes. Understanding the precise mechanisms by which TERF2 operates is therefore of great interest in the field of oncology and gerontology.

Related Pages

• Telomere
• Shelterin
• DNA damage response
• Chromosome