TIN2 mediates functions of TRF2 at human telomeres.
Telomeres are protective structures at chromosome ends and are crucial for genomic stability. Mammalian TRF1 and TRF2 bind the double-stranded telomeric repeat sequence and in turn are bound by TIN2, TANK1, TANK2, and hRAP1. TRF1 is a negative regulator of telomere length in telomerase-positive cells, whereas TRF2 is important for telomere capping. TIN2 was identified as a TRF1-interacting protein that mediates TRF1 function. We show here that TIN2 also interacts with TRF2 in vitro and in yeast and mammalian cells. TIN2 mutants defective in binding of TRF1 or TRF2 induce a DNA damage response and destabilize TRF1 and TRF2 at telomeres in human cells. Our findings suggest that the functions of TRF1 and TRF2 are linked by TIN2.
Kim
Sahn-ho
SH
Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Beausejour
Christian
C
Davalos
Albert R
AR
Kaminker
Patrick
P
Heo
Seok-Jin
SJ
Campisi
Judith
J
D002460:Cell Line; D006801:Humans; D011485:Protein Binding; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000502:physiology*; D034501:Telomere-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D035321:Telomeric Repeat Binding Protein 1 / Q000378:metabolism; D035341:Telomeric Repeat Binding Protein 2 / Q000378:metabolism*
D011994:Recombinant Proteins; C440868:TINF2 protein, human; D034501:Telomere-Binding Proteins; D035321:Telomeric Repeat Binding Protein 1; D035341:Telomeric Repeat Binding Protein 2; D019098:Telomerase