Figure 3.

TIN2 stimulates probe clustering. (A) The telomere probes (6X-Tel and B-6X-Tel) used in the assay. (B) Reaction mixtures containing probes (10 µl) and the proteins indicated were analysed by electrophoretic mobility-shift assays. Asterisks indicate TRF1–probe complexes that correspond to the binding of one, two or three TRF1 dimers, as indicated by the number of asterisks. (C) Reaction mixtures (90 µl) in the absence ('buffer') or in the presence of TRF1 (0.25 µM), TIN2 (0.25 µM) or both were captured on streptavidin–agarose beads, released by phenol extraction, precipitated with ethanol, and analysed by native polyacrylamide gel electrophoresis. The B-6X-Tel probe was either labelled (lanes 1–5) or unlabelled (lanes 6–9). For lane 5, excess (100×) unlabelled double-stranded (TTAGGG)₇ was added before the addition of proteins ('competitor').