A mammalian factor that binds telomeric TTAGGG repeats in vitro.
We have identified a DNA-binding activity with specificity for the TTAGGG repeat arrays found at mammalian telomeres. This factor, called TTAGGG repeat factor (TRF), is present in nuclear extracts of human, mouse, and monkey cells. TRF from HeLa cells was characterized in detail by electrophoretic mobility shift assays. It binds double-stranded TTAGGG repeats in linear and circular DNAs. Single-stranded repeats are not recognized. The optimal site for TRF appears to contain more than six contiguous TTAGGG repeats. Tandem arrays of TAGGG, TTTAGGG, TTTTAGGG, TTGGGG, and TTAGGC repeats do not bind TRF well, indicating that TRF preferentially recognizes the telomeric repeat sequence present at mammalian chromosome ends. The apparent molecular mass of this factor, based on recovery of TRF from sodium dodecyl sulfate-polyacrylamide gels, is approximately 50 kDa. We suggest that TRF binds along the length of mammalian telomeres.
Zhong
Z
Z
Rockefeller University, New York, New York 10021.
Shiue
L
L
Kaplan
S
S
de Lange
T
T
D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D000882:Haplorhini; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D013045:Species Specificity; D016615:Telomere
D004268:DNA-Binding Proteins; D004247:DNA