Identification of the functional domain of p21WAF1/CIP1 that protects cells from cisplatin cytotoxicity

2005 ◽  
Vol 289 (3) ◽  
pp. F514-F520 ◽  
Author(s):  
Fang Yu ◽  
Judit Megyesi ◽  
Robert L. Safirstein ◽  
Peter M. Price

The p21 cyclin-dependent kinase (cdk) inhibitor protects cells from cisplatin cytotoxicity in vivo and in vitro. However, the mechanism of protection is not known. Separate p21 domains are known to interact with several different proteins having proapoptotic functions. To investigate the mechanism of protection by p21, we have constructed adenoviruses encoding the different domains of p21. We were able to localize the protective activity to a region of 54 amino acids containing the cyclin-cdk interacting moiety. Other protein binding domains of p21, including the NH2-terminal procaspase-3 interactive region and the COOH-terminal region containing the proliferating cell nuclear antigen binding domain and the nuclear localization signal, had little protective effect on cisplatin cytotoxicity. The dependence of cisplatin cytotoxicity on cdk2 activity was also demonstrated because 1) cisplatin caused a marked increase in cdk2 activity, which was prevented by the p21 expression adenovirus, and 2) a cdk2 dominant-negative adenovirus also protected cells from cisplatin-induced apoptosis. Thus the data suggest that the mechanism of p21 protection is by direct inhibition of cdk2 activity and that cisplatin-induced apoptosis is caused by a cdk2-dependent pathway.

1999 ◽  
Vol 19 (8) ◽  
pp. 5373-5382 ◽  
Author(s):  
Ronald Gary ◽  
Min S. Park ◽  
John P. Nolan ◽  
Helen L. Cornelius ◽  
Olga G. Kozyreva ◽  
...  

ABSTRACT Fen1/Rad27 nuclease activity, which is important in DNA metabolism, is stimulated by proliferating cell nuclear antigen (PCNA) in vitro. The in vivo role of the PCNA interaction was investigated in the yeast Rad27. A nuclease-defective rad27 mutation had a dominant-negative effect that was suppressed by a mutation in the PCNA binding site, thereby demonstrating the importance of the Rad27-PCNA interaction. The PCNA-binding defect alone had little effect on mutation, recombination, and the methyl methanesulfonate (MMS) response in repair-competent cells, but it greatly amplified the MMS sensitivity of a rad51 mutant. Furthermore, the PCNA binding mutation resulted in lethality when combined with a homozygous or even a heterozygous pol3-01 mutation in the 3′→5′ exonuclease domain of DNA polymerase δ. These results suggest that phenotypically mild polymorphisms in DNA metabolic proteins can have dramatic consequences when combined.


1989 ◽  
Vol 9 (1) ◽  
pp. 57-66
Author(s):  
M Zuber ◽  
E M Tan ◽  
M Ryoji

Proliferating cell nuclear antigen (PCNA) (also called cyclin) is known to stimulate the activity of DNA polymerase delta but not the other DNA polymerases in vitro. We injected a human autoimmune antibody against PCNA into unfertilized eggs of Xenopus laevis and examined the effects of this antibody on the replication of injected plasmid DNA as well as egg chromosomes. The anti-PCNA antibody inhibited plasmid replication by up to 67%, demonstrating that PCNA is involved in plasmid replication in living cells. This result further implies that DNA polymerase delta is necessary for plasmid replication in vivo. Anti-PCNA antibody alone did not block plasmid replication completely, but the residual replication was abolished by coinjection of a monoclonal antibody against DNA polymerase alpha. Anti-DNA polymerase alpha alone inhibited plasmid replication by 63%. Thus, DNA polymerase alpha is also required for plasmid replication in this system. In similar studies on the replication of egg chromosomes, the inhibition by anti-PCNA antibody was only 30%, while anti-DNA polymerase alpha antibody blocked 73% of replication. We concluded that the replication machineries of chromosomes and plasmid differ in their relative content of DNA polymerase delta. In addition, we obtained evidence through the use of phenylbutyl deoxyguanosine, an inhibitor of DNA polymerase alpha, that the structure of DNA polymerase alpha holoenzyme for chromosome replication is significantly different from that for plasmid replication.


Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 75 ◽  
Author(s):  
Sara Paola Hernández Martínez ◽  
Teodoro Iván Rivera González ◽  
Moisés Armides Franco Molina ◽  
Juan José Bollain y Goytia ◽  
Juan José Martínez Sanmiguel ◽  
...  

The development of new nanomaterials to promote wound healing is rising, because of their topical administration and easy functionalization with molecules that can improve and accelerate the process of healing. A nanocomposite of gold nanoparticles (AuNPs) functionalized with calreticulin was synthetized and evaluated. The ability of the nanocomposite to promote proliferation and migration was determined in vitro, and in vivo wound healing was evaluated using a mice model of diabetes established with streptozotocin (STZ). In vitro, the nanocomposite not affect the cell viability and the expression of proliferating cell nuclear antigen (PCNA). Moreover, the nanocomposite promotes the clonogenicity of keratinocytes, endothelial cells, and fibroblasts, and accelerates fibroblast migration. In vivo, mice treated with the nanocomposite presented significantly faster wound healing. The histological evaluation showed re-epithelization and the formation of granular tissue, as well as an increase of collagen deposition. Therefore, these results confirm the utility of AuNPs–calreticulin nanocomposites as potential treatment for wound healing of diabetic ulcers.


2002 ◽  
Vol 158 (2) ◽  
pp. 321-329 ◽  
Author(s):  
Hiroyuki Tanaka ◽  
Toshihide Yamashita ◽  
Minoru Asada ◽  
Shuki Mizutani ◽  
Hideki Yoshikawa ◽  
...  

p21Cip1/WAF1 has cell cycle inhibitory activity by binding to and inhibiting both cyclin/Cdk kinases and proliferating cell nuclear antigen. Here we show that p21Cip1/WAF1 is induced in the cytoplasm during the course of differentiation of chick retinal precursor cells and N1E-115 cells. Ectopic expression of p21Cip1/WAF1 lacking the nuclear localization signal in N1E-115 cells and NIH3T3 cells affects the formation of actin structures, characteristic of inactivation of Rho. p21Cip1/WAF1 forms a complex with Rho-kinase and inhibits its activity in vitro and in vivo. Neurite outgrowth and branching from the hippocampal neurons are promoted if p21Cip1/WAF1 is expressed abundantly in the cytoplasm. These results suggest that cytoplasmic p21Cip1/WAF1 may contribute to the developmental process of the newborn neurons that extend axons and dendrites into target regions.


2003 ◽  
Vol 23 (2) ◽  
pp. 721-732 ◽  
Author(s):  
Lisa A. Anderson ◽  
Neil D. Perkins

ABSTRACT The RelA (p65) subunit of NF-κB is an important regulator of inflammation, proliferation, and apoptosis. We have discovered that the large subunit, p140, of replication factor C (RFC) can function as a regulator of RelA. RFC is a clamp loader, facilitating the addition and removal of proliferating-cell nuclear antigen from DNA during replication and repair but can also interact directly with the retinoblastoma tumor suppressor protein and the transcription factor C/EBPα. We find that RFC (p140) interacts with RelA both in vitro and in vivo and stimulates RelA transactivation. In contrast, coexpression of fragments of RFC (p140) that mediate the interaction with RelA results in transcriptional inhibition. The significance of this regulation was confirmed by using short interfering RNA oligonucleotides targeted to RFC (p140). Down regulation of endogenous RFC (p140) inhibits expression from a chromosomally integrated reporter plasmid induced by endogenous, TNF-α-activated NF-κB. Dominant negative fragments of RFC (p140) also cooperate with overexpressed RelA to induce cell death. Interestingly, RFC (p140) also interacts with the tumor suppressor p53. Taken together, these observations suggest that, in addition to its previously described function in DNA replication and repair, RFC (p140) has an important role as a regulator of transcription and NF-κB activity.


Reproduction ◽  
2013 ◽  
Vol 145 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Carla N Olivares ◽  
Mariela A Bilotas ◽  
Analía G Ricci ◽  
Rosa Inés Barañao ◽  
Gabriela F Meresman

Endometriosis is a benign gynecological disease. Cyclooxygenase-2 (COX-2) and aromatase proteins have been shown to be overexpressed in eutopic endometrium from women suffering from this disease compared to disease-free women. Furthermore, inhibition of these molecules individually was demonstrated to have antiproliferative and proapoptotic effects both in vitro and in vivo in several models. In this study, the effect of combining celecoxib, a selective COX-2 inhibitor, and anastrozole, an aromatase inhibitor, on the implantation and growth of endometriotic like lesions in a murine model of endometriosis was evaluated. Endometriosis was surgically induced in female BALB/c mice. After 28 days of treatment with celecoxib, anastrozole, or their combination, animals were killed and lesions were counted, measured, excised, and fixed. Immunohistochemistry for proliferating cell nuclear antigen and CD34 was performed for assessment of cell proliferation and vascularization. TUNEL technique was performed for apoptosis evaluation. Celecoxib was the only treatment to significantly reduce the number of lesions established per mouse, their size and vascularized area. In addition, cell proliferation was significantly diminished and apoptosis was significantly enhanced by both individual treatments. When the therapies were combined, they reversed their effects. These results confirm that celecoxib and anastrozole separately decrease endometriotic growth, but when combined they might have antagonizing effects.


2002 ◽  
Vol 22 (18) ◽  
pp. 6480-6486 ◽  
Author(s):  
Ildiko Unk ◽  
Lajos Haracska ◽  
Xavier V. Gomes ◽  
Peter M. J. Burgers ◽  
Louise Prakash ◽  
...  

ABSTRACT The Apn2 protein of Saccharomyces cerevisiae contains 3′→5′ exonuclease and 3′-phosphodiesterase activities, and these activities function in the repair of DNA strand breaks that have 3′-damaged termini and which are formed in DNA by the action of oxygen-free radicals. Apn2 also has an AP endonuclease activity and functions in the removal of abasic sites from DNA. Here, we provide evidence for the physical and functional interaction of Apn2 with proliferating cell nuclear antigen (PCNA). As indicated by gel filtration and two-hybrid studies, Apn2 interacts with PCNA both in vitro and in vivo and mutations in the consensus PCNA-binding motif of Apn2 abolish this interaction. Importantly, PCNA stimulates the 3′→5′ exonuclease and 3′-phosphodiesterase activities of Apn2. We have examined the involvement of the interdomain connector loop (IDCL) and of the carboxy-terminal domain of PCNA in Apn2 binding and found that Apn2 binds PCNA via distinct domains dependent upon whether the binding is in the absence or presence of DNA. In the absence of DNA, Apn2 binds PCNA through its IDCL domain, whereas in the presence of DNA, when PCNA has been loaded onto the template-primer junction by replication factor C, the C-terminal domain of PCNA mediates the binding.


2007 ◽  
Vol 293 (1) ◽  
pp. F52-F59 ◽  
Author(s):  
Fang Yu ◽  
Judit Megyesi ◽  
Robert L. Safirstein ◽  
Peter M. Price

E2F1 is a key regulator that links cell cycle progression and cell death. E2F1 activity is controlled by Cdk2-cyclin complexes via several mechanisms, such as phosphorylation of retinoblastoma protein (pRb) to release E2F1, direct phosphorylation, and stable physical interaction. We have demonstrated that cisplatin cytotoxicity depends on Cdk2 activity, and Cdk2 inhibition protects kidney cells from cisplatin-induced cell death in vitro and in vivo. Now we show that E2F1 is an important downstream effector of Cdk2 that accumulates in mouse kidneys and in cultured mouse proximal tubular cells (TKPTS) after cisplatin exposure by a Cdk2-dependent mechanism. Direct inhibition of E2F1 by transduction with adenoviruses expressing an E2F1-binding protein (TopBP1) protected TKPTS cells from cisplatin-induced apoptosis, whereas overexpression of E2F1 caused cell death. Moreover, E2F1 knockout mice were markedly protected against cisplatin nephrotoxicity by both functional and histological criteria. Collectively, cisplatin-induced cell death is dependent on Cdk2 activity, which is at least partly through the Cdk2-E2F1 pathway both in vitro and in vivo.


1989 ◽  
Vol 9 (1) ◽  
pp. 57-66 ◽  
Author(s):  
M Zuber ◽  
E M Tan ◽  
M Ryoji

Proliferating cell nuclear antigen (PCNA) (also called cyclin) is known to stimulate the activity of DNA polymerase delta but not the other DNA polymerases in vitro. We injected a human autoimmune antibody against PCNA into unfertilized eggs of Xenopus laevis and examined the effects of this antibody on the replication of injected plasmid DNA as well as egg chromosomes. The anti-PCNA antibody inhibited plasmid replication by up to 67%, demonstrating that PCNA is involved in plasmid replication in living cells. This result further implies that DNA polymerase delta is necessary for plasmid replication in vivo. Anti-PCNA antibody alone did not block plasmid replication completely, but the residual replication was abolished by coinjection of a monoclonal antibody against DNA polymerase alpha. Anti-DNA polymerase alpha alone inhibited plasmid replication by 63%. Thus, DNA polymerase alpha is also required for plasmid replication in this system. In similar studies on the replication of egg chromosomes, the inhibition by anti-PCNA antibody was only 30%, while anti-DNA polymerase alpha antibody blocked 73% of replication. We concluded that the replication machineries of chromosomes and plasmid differ in their relative content of DNA polymerase delta. In addition, we obtained evidence through the use of phenylbutyl deoxyguanosine, an inhibitor of DNA polymerase alpha, that the structure of DNA polymerase alpha holoenzyme for chromosome replication is significantly different from that for plasmid replication.


2006 ◽  
Vol 84 (5) ◽  
pp. 669-676 ◽  
Author(s):  
Stanislav N. Naryzhny ◽  
Leroi V. DeSouza ◽  
K.W. Michael Siu ◽  
Hoyun Lee

Its toroidal structure allows the proliferating cell nuclear antigen (PCNA) to wrap around and move along the DNA fiber, thereby dramatically increasing the processivity of DNA polymerization. PCNA is also involved in the regulation of a wide spectrum of other biological functions, including epigenetic inheritance. We have recently reported that mammalian PCNA forms a double trimer complex, which may be critically important in coordinating DNA replication and other cellular functions. To gain a better understanding of the stability of PCNA complexes, we characterized the physico-chemical properties of the PCNA structure by in vivo and in vitro approaches. The data obtained by gel filtration and nondenaturing gel electrophoresis of native PCNA molecules confirm our previous observations, obtained using formaldehyde crosslinking, in which PCNA exists in the cell as a double trimer. We have also found that optimal pH (pH 6.5–7.5) is critical for the stability of the PCNA structure. The presence or absence of ATP, dithiothreitol, and Mg2+ does not affect the stability of the PCNA trimer or double trimer. However, 0.02% SDS can effectively inhibit PCNA double trimer, but not single trimer, formation. Interestingly, glycerol and ammonium sulfate significantly destabilize both PCNA trimer and double trimer structures.


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