Skip to main content
. 2018 Jul 17;1(4):e201800121. doi: 10.26508/lsa.201800121

Figure 7. Hypothetical model for transformation-associated changes at telomeres.

Figure 7.

(A) The SV40 large T and small t antigens inhibit p53, RB, and PP2A. In addition, SV40 early gene expression leads to up-regulation of factors, which promote telomere protection and replication. (B) Telomere replication requires TRF1. In the absence of TRF1, G-quadruplex structures accumulate at telomeres, which become cleaved during replication and repaired by SAMHD1-dependent repair. In the absence of both TRF1 and SAMHD1, double-strand breaks are retained. Telomere synthesis proceeds downstream of the breaks mediated by replication fork restart, telomerase, or replication fork firing from within telomeric repeats.