TERF2
TERF2 (telomeric repeat binding factor 2, also known as TRF2 or TRBF2) is a telomere-specific DNA-binding protein and a core component of the shelterin complex. It binds double-stranded telomeric repeats and protects chromosome ends from inappropriate processing. Browse Assay Genie's current range of TERF2 research reagents below, or read on for the biology behind the target.
TERF2 binds the telomeric double-stranded 5'-TTAGGG-3' repeat and plays a central role in telomere maintenance and in protection against end-to-end fusion of chromosomes. It is a component of the shelterin complex (telosome), which associates with arrays of TTAGGG repeats added by telomerase and regulates telomere length. Without this protective activity, telomeres are no longer hidden from DNA damage surveillance, and chromosome ends are inappropriately processed by DNA repair pathways.
Beyond DNA binding, TERF2 recruits factors and enzymes needed for telomere protection, including TERF2IP/RAP1 and the nuclease DCLRE1B/Apollo. Together with DCLRE1B/Apollo, it helps form the telomeric loop (T loop) by generating a 3' single-stranded overhang at leading-end telomeres. T loops have been proposed to protect chromosome ends from degradation and repair. TERF2 is also required to activate the exonuclease activity of DCLRE1B/Apollo, preferentially binds positively supercoiled DNA, and with DCLRE1B/Apollo controls the amount of topoisomerase (TOP1, TOP2A and TOP2B) present during telomere replication, preventing aberrant telomere topology. By recruiting TERF2IP/RAP1, it contributes to repressing homology-directed repair, which can affect telomere length.
The human TERF2 gene belongs to the Myb/SANT domain containing and shelterin complex gene groups. NCBI describes the protein as present at telomeres in metaphase and as a second negative regulator of telomere length, after TERF1. TERF2 shares telomere-binding activity and domain organisation with TERF1, but its N terminus is basic rather than acidic.
TERF2 is central to telomere maintenance and length regulation, making it a key subject for studies of how chromosome ends are protected.
Loss of TERF2 protection exposes telomeres to DNA damage surveillance and repair pathways, so it is used to study end processing.
TERF2 recruits TERF2IP/RAP1 and DCLRE1B/Apollo, offering a route into shelterin assembly and its protein partnerships.
TERF2 helps control topoisomerase levels during telomere replication and T loop formation, relevant to telomere structure research.
TERF2 binds double-stranded 5'-TTAGGG-3' telomeric repeats and protects chromosome ends from end-to-end fusion. As part of the shelterin complex it regulates telomere length, recruits TERF2IP/RAP1 and DCLRE1B/Apollo, and helps form the T loop.
TERF2 is also known as TRF2 and TRBF2, and its full name is telomeric repeat binding factor 2. UniProt lists it as telomeric repeat-binding factor 2. It is distinct from TERF1, which has an acidic rather than basic N terminus.
A mouse ortholog, Terf2, is recorded for the human gene. Researchers working in other species should check the datasheet of any product for its validated reactivity before use.
Other shelterin complex members and telomere-associated proteins with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q15554; product specifications from Assay Genie datasheets.