TERF2

Description

The TERF2 (telomeric repeat binding factor 2) is a protein-coding gene located on chromosome 16.

Telomeric repeat-binding factor 2 (TERF2) is a protein essential for telomere maintenance and protection. It binds to telomeres throughout the cell cycle and is also known as TRF2 or TRBF2. TERF2 is encoded by the TERF2 gene in humans. It is a component of the shelterin nucleoprotein complex, which acts as a protective cap at chromosome ends. TERF2 is a negative regulator of telomere length, helping to maintain the proper length of telomeres. TERF2 has a similar structure to TERF1, both containing a C-terminal Myb motif and a dimerization domain near their N-terminus. However, TERF2 only forms homodimers and does not heterodimerize with TERF1. TERF2 has a basic N-terminus, unlike TERF1's acidic N-terminus, and is more conserved, suggesting distinct functions. TERF2 contains four domains that allow it to interact with other shelterin proteins and specific DNA sequences. The TERF Homology Domain (TRFH) promotes homodimerization of TERF2.

TERF2 binds to the repetitive DNA sequence TTAGGG at telomeres, playing a crucial role in maintaining telomere length and preventing chromosome ends from fusing together. It recruits proteins like TERF2IP/RAP1 and DCLRE1B/Apollo to telomeres, which are essential for telomere protection. TERF2 is a component of the shelterin complex, which safeguards telomeres from being recognized as DNA damage and incorrectly processed by DNA repair mechanisms. In collaboration with DCLRE1B/Apollo, TERF2 facilitates the formation of telomeric loops (T-loops), which shield chromosome ends from degradation and repair. It is required for the recruitment of DCLRE1B/Apollo to telomeres and activates its exonuclease activity. TERF2 exhibits a preference for binding to positively supercoiled DNA. It works with DCLRE1B/Apollo to regulate the levels of DNA topoisomerases (TOP1, TOP2A, and TOP2B) needed for telomere replication during replication fork passage, preventing aberrant telomere structure. TERF2 recruits TERF2IP/RAP1 to telomeres, inhibiting homology-directed repair (HDR), which can influence telomere length.

TERF2 is also known as TRBF2, TRF2.

Associated Diseases

WES Whole Exome Sequencing