Human Proliferating Cell Nuclear Antigen, Poly(ADP-ribose) Polymerase-1, and p21 /

Abstract

We addressed the analysis of the physical and functional association of proliferating cell nuclear antigen (PCNA), a protein involved in many DNA transactions, with poly(ADP-ribose) polymerase (PARP-1), an enzyme that plays a crucial role in DNA repair and interacts with many DNA replication/repair factors. We demonstrated that PARP-1 and PCNA co-immunoprecipitated both from the soluble and the DNA-bound fraction isolated from S-phase-synchronized HeLa cells. Immunoprecipitation experiments with purified proteins further confirmed a physical association between PARP-1 and PCNA. To investigate the effect of this association on PARP-1 activity, an assay based on the incorporation of radioactive NAD was performed. Conversely, the effect of PARP-1 on PCNA-dependent DNA synthesis was assessed by a DNA polymerase ␦ assay. A marked inhibition of both reactions was found. Unexpectedly, PARP-1 activity also decreased in the presence of p21 waf1/cip1. By pull-down experiments, we provided the first evidence for an association between PARP-1 and p21, which involves the C-terminal part of p21 protein. This association was further demonstrated to occur also in vivo in MNNG (N-methyl-N-nitro-N-nitrosoguanidine)-treated human fibroblasts. These observations suggest that PARP-1 and p21 could cooperate in regulating the functions of PCNA during DNA replication/repair.1 is a DNA-nick sensor protein that uses ␤-NAD ϩ as a substrate for transferring ADP-ribose moieties to itself and to nuclear acceptor proteins (1). PARP-1 modulates the structure and function of many proteins involved in DNA metabolism (2, 3), co-purifies with some members of the DNA synthesome (4 -6), and is a component of replication-competent complexes (7). It has been shown previously that PARP-1 co-immunoprecipitates with the proliferating cell nuclear antigen (PCNA) (4, 5), which is a pivotal protein in DNA replication, DNA repair, and cell cycle control. A number of proteins involved in DNA replication and repair interact with PCNA (reviewed in Refs. 8 -11). Most of the PCNA-interacting proteins have a QXX(h)XX(a)(a) box that specifically binds the interdomain connector loop (12). PARP-1 shows a putative PCNA-binding consensus sequence (QDLIK-MIF) at position 669 within the NAD-binding domain that is essential for the conversion of NAD into ADP-ribose and, consequently, for PARP-1 catalytic activity.In this work we sought to attain a greater understanding of the interaction between PARP-1 and PCNA. We have demonstrated that PARP-1 and PCNA co-immunoprecipitate both from the soluble and the DNA-bound fraction isolated from S-phase-synchronized HeLa cells. These results were supported by immunoprecipitation experiments with purified proteins. To investigate the effect of this association on the properties of each protein, we evaluated the conversion of NAD into ADP-ribose (PARP assay) as well as PCNA-dependent nucleotide incorporation (pol ␦ assay), and we found a marked inhibition of both reactions. Unexpectedly, an inhibitory effect on PARP-1 activity was al...

The ADP-ribosyltransferase PARP10/ARTD10 Interacts with Proliferating Cell Nuclear Antigen (PCNA) and Is Required for DNA Damage Tolerance

“…PARP10 co-purified with PCNA regardless of PARP1 levels. PARP1 also co-immunoprecipitated with PCNA in control cells, as previously shown (45).…”

“…It was previously shown that PCNA interacts with another member of the PARP family, namely PARP1, to inhibit its ADPribose polymerase activity (45). When we depleted PARP1 using siRNA, we observed that PARP10 co-immunoprecipitated with PCNA to the same extent as in control cells (Fig.…”

Spatiotemporal dynamics of p21CDKN1A protein recruitment to DNA-damage sites and interaction with proliferating cell nuclear antigen

“…In our system, p21 protein was not completely degraded either at low (2.5 J/m 2 ) or high (10 J/m 2 ) UV doses. In fact, other mechanisms regulating gene expression after UV damage (Barley et al, 1998;McKay et al, 1998), or after other types of DNA lesions (Frouin et al, 2003), may influence p21 turnover. An important factor limiting p21 proteasomal degradation is the interaction with PCNA, because the C8 proteasome subunit binds p21 at its C-terminal region, where the PCNA binding site is located (Touitou et al, 2001).…”

Poly(ADP-ribosyl)ated chromatin domains: access granted

“…Associations with PCNA, p53, p21 Waf1/Cip1 , Cockayne syndrome B protein and chromatin assembly factor-1 (CAF-1) (Flohr et al, 2003;Frouin et al, 2003;Okano et al, 2003;Wieler at al., 2003) offer the equally exciting possibility that it is also part of a more general machinery. It will be interesting, therefore, to characterize these associations and determine how PARP-1 and PARP-2 activities and/or the scaffolding properties of poly(ADP-ribose) contribute to the function(s) and composition of these modules.…”