p53 binds telomeric single strand overhangs and t-loop junctions in vitro.
The interaction of p53 with a human model telomere in vitro was examined by electron microscopy. p53 demonstrated a sequence-independent affinity for telomeric DNA in vitro, localizing to the 3' single strand overhang and the t-loop junction both in the presence and absence of associated TRF2. Binding was not observed above background along the duplex telomeric repeats. However, the efficiency of TRF2-catalyzed t-loop formation on the model DNA was increased 2-fold in the presence of p53 although a variety of single strand or Holliday junction-binding proteins did not facilitate t-loop formation. These results suggest that p53 has an active role in telomere maintenance and structure through association with the t-loop junction.
Stansel
Rachel M
RM
Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7295, USA.
Subramanian
Deepa
D
Griffith
Jack D
JD
D000818:Animals; D002384:Catalysis; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007313:Insecta; D008854:Microscopy, Electron; D011485:Protein Binding; D016615:Telomere / Q000378:metabolism* / Q000648:ultrastructure; D035341:Telomeric Repeat Binding Protein 2; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D004268:DNA-Binding Proteins; D035341:Telomeric Repeat Binding Protein 2; D016159:Tumor Suppressor Protein p53; D004247:DNA