TERF1
Domain
The acidic N-terminal domain binds to the ankyrin repeats of TNKS1 and TNKS2. The C-terminal domain binds microtubules.
The TRFH dimerization region mediates the interaction with TINF2.
The HTH domain is an independent structural unit and mediates binding to telomeric DNA.
Function
Binds the telomeric double-stranded 5'-TTAGGG-3' repeat and negatively regulates telomere length. Involved in the regulation of the mitotic spindle. Component of the shelterin complex (telosome) that is involved in the regulation of telomere length and protection. Shelterin associates with arrays of double-stranded 5'-TTAGGG-3' repeats added by telomerase and protects chromosome ends; without its protective activity, telomeres are no longer hidden from the DNA damage surveillance and chromosome ends are inappropriately processed by DNA repair pathways.
Post-translational modifications
Phosphorylated preferentially on Ser-219 in an ATM-dependent manner in response to ionizing DNA damage.
ADP-ribosylation by TNKS1 or TNKS2 diminishes its ability to bind to telomeric DNA.
Ubiquitinated by RLIM/RNF12, leading to its degradation by the proteasome. Ubiquitinated by a SCF (SKP1-CUL1-F-box protein) ubiquitin-protein ligase complex, leading to its degradation by the proteasome.
Tissue Specificity
Highly expressed and ubiquitous. Isoform Pin2 predominates.
Cellular localization
- Nucleus
- Cytoplasm
- Cytoskeleton
- Spindle
- Chromosome
- Telomere
- Colocalizes with telomeric DNA in interphase and prophase cells. Telomeric localization decreases in metaphase, anaphase and telophase. Associates with the mitotic spindle (PubMed:11943150). Colocalizes with TRIOBP isoform 1 at the telomeres in interphase (PubMed:24692559).
Alternative names
PIN2, TRBF1, TRF, TRF1, TERF1, Telomeric repeat-binding factor 1, NIMA-interacting protein 2, TTAGGG repeat-binding factor 1, Telomeric protein Pin2/TRF1