TRF 1 | TTAGGG repeat binding factor 1

TRF1 well known as TTAGGG repeat-binding factor 1 or Telomeric repeat-binding factor 1 is a nuclear protein known to bind the telomeric double-stranded TTAGGG repeat and negatively regulate telomere length and protection. This DNA associated regulatory protein contains a HTH myb-type DNA-binding domain and is known to associate with the mitotic spindle and regulate it. A component of the shelterin complex (telosome) composed of TERF1, TERF2, TINF2, TERF2IP ACD and POT1, TERF1 associates with arrays of double-stranded TTAGGG repeats added by telomerase and protects chromosome ends. It has two isoforms of TRF1 and Pin2 of which Pin2 expression is tightly regulated during the cell cycle. TRF1 colocalizes with telomeric DNA in interphase and metaphase cells and is located at chromosome ends during metaphase.