Back to article: RPA and Pif1 cooperate to remove G-rich structures at both leading and lagging strand


image description

FIGURE 8: Mechanistic model for the unfolding of CEB1-G-rich structures by RPA and Pif1. (A) In WT cells, when the G-rich strand (light grey) is on leading strand (left part, CEB1 leading), stable G-quadruplexes structures are efficiently removed by Pif1, as proposed by Lopes and colleagues [33]. At the leading strand, RPA may cooperate with Pif1 either by preventing the refolding of the G4 structure or by recruiting Pif1 to the leading strand. When the G-rich strand (light grey) is replicated by the lagging polymerase (right part, CEB1 lagging) binding of RPA to the G-rich strand prevents formation of stable G-rich secondary structures. In this context, Pif1 is dispensable. (B) In the rfa1-D228Y mutant, at the leading strand (left part), the reduced affinity of RPA for G-rich ssDNA either reduce the ability of RPA to prevent the refolding of the G4 structure or decrease Pif1 recruitment. The decrease in RPA affects G4-unwinding and leads to the formation of CEB1 rearrangements. At the lagging strand (middle part), the decrease affinity of RPA for G-rich ssDNA facilitates the formation of stable G-rich structures, affects their unwinding, and generates CEB1 instability. In such a case, overexpression of Pif1 (right part) can efficiently unwind G-rich structures, leading to CEB1 size conservation.

33. Lopes J, Piazza A, Bermejo R, Kriegsman B, Colosio A, Teulade-Fichou M-P, Foiani M and Nicolas A (2011). G-quadruplex-induced instability during leading-strand replication. Embo J 30(19): 4033–4046. 10.1038/emboj.2011.316

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this. Please refer to our "privacy statement" and our "terms of use" for further information.

Close