Proliferating cell nuclear antigen

J Clin Invest. 1994;94(4):1365-1372. https://doi.org/10.1172/JCI117471. Mycobacteria have been implicated in the pathogenesis of autoimmunity. To determine the potential effect of mycobacterial antigens on peripheral blood mononuclear cells (PBMC), we analyzed PBMC incubated with the acetone-precipitable fraction of Mycobacterium tuberculosis (APMT) for changes in cellular protein expression. Two-dimensional gel analysis showed induction of a 36-kD polypeptide identified as proliferating cell nuclear antigen (PCNA), a known autoantigen, after incubation with AP-MT. PCNA plays a role in cell proliferation and is expressed as a late growth regulated factor. However, its synthesis in response to AP-MT was induced as an early event. The early induction of PCNA was regulated at a posttranscriptional level and was restricted to T cells. Treatment of PBMC with known T cell mitogens, namely PHA, anti-CD3 antibodies, and staphylococcal superantigens failed to induce an early PCNA increase. The distinct characteristics of the AP-MT effect on PCNA expression suggest a separate mechanism of induction in response to AP-MT, compared with the late increase observed in response to mitogens. The induction of PCNA in response to mycobacterial antigens may represent a pathogenically relevant mechanism in autoimmunity.

Two-dimen- sional gel analysis showed induction of a 36-kD polypeptide identified as proliferating cell nuclear antigen (PCNA), a known autoantigen, after incubation with AP-MT. PCNA pla[r]

We have studied the influence of variations in dietary protein (P) and digestible carbohydrate (C), the quantity of food eaten, and insect age during the fifth instar on the expression of the proliferating cell nuclear antigen (PCNA) in the epithelial cells of the midgut (with special reference to the midgut caeca) in the African migratory locust, Locusta migratoria. Densitometric analysis of PCNA-immunostained cells was used as an indirect measure of the levels of expression of PCNA, and a PCNA cellular index (PCNA-I) was obtained. Measurements of the DNA content of the cells have also been carried out by means of microdensitometry of Feulgen-stained, thick sections of midgut. A comparison between the PCNA nuclear level and the DNA content was performed. The PCNA levels were significantly different among the cells of the five regions studied: caeca, anterior ventricle, medial ventricle, posterior ventricle and ampullae of the Malpighian tubules. We have studied in more detail the region with highest PCNA-I, i.e. the caeca. The quality and the quantity of food eaten under ad libitum conditions were highly correlated with both the PCNA and DNA levels in the caeca cells. Locusts fed a diet with a close to

Methods: Twenty cases of OSCC were histologically assessed to evaluate the correlation between proliferating cell nuclear antigen expression and invasive front grading. Each case was first assessed on a haematoxylin and eosin stained slide and an invading front grading (IFG) score was determined. In order to obtain a PCNA score, immunohistological staining was carried out using the peroxidase-labelled streptavidin-biotin technique with the monoclonal antibody PC10.

SMCX association with proliferating cell nuclear antigen is regulated by the cell cycle PCNA is mainly expressed in S phase. To determine if SMCX levels similarly fluctuate inside cells during the cell cycle, we performed immunofluorescence experiments, and found that SMCX was expressed both in cells with strong staining with anti-BrdU antibody (S phase) and in cells showing very little BrdU staining (Figure 3A). How- ever, SMCX in S phase cells had a different, granular pat- tern of distribution compared with other cells. This result suggests a possible SMCX redistribution in S phase.

In this study, a monoclonal antibody against proliferating cell nuclear antigen (cyclin) was used to determine the percentage of positive neoplastic cells in benign, borderline and malig[r]

60 Proliferating cell nuclear antigen (PCNA) is a cell cycle related antigen frequently used in the study of cell kinetics. PCNA is a 36KDa acidic nuclear non-histone nuclear protein associated with the cell cycle. It is an auxillary protein of DNA polymerase necessary for synthesis of DNA. The distribution of PCNA in the cell cycle increases through G1, peaks at the G1/S interphase and decreases through G2 phase. PCNA expression is used as a marker of cell proliferation because the cells remain for a longer time in late G1/S phase when proliferating. 7 , 8 An increase in PCNA levels may be induced by growth factors or as a result of DNA damage in the absence of cell cycle. 1 0 PCNA is also expressed in process of DNA replication and repair mechanisms as well and so it may be expressed in cells not synthesizing DNA. 9 PCNA expression is increased in cell cycle dysregulation. Immunostaining with monoclonal antibody PC10 against this antigen has been shown to demonstrate the proliferative compartment of normal tissue. An increased expression of these markers are expressed actively in proliferating cells, particularly in neoplasia. 9 , 1 0

The human T-cell leukemia virus type 1 (HTLV-1) transforming protein, Tax, is a potent transactivator of both viral and cellular gene expression. The ability of Tax to transform cells is believed to depend on its transactivation of cellular-growth-regulatory genes. Expression of proliferating cell nuclear antigen (PCNA) is intimately linked to cell growth and DNA replication and repair. By testing a series of PCNA promoter deletion constructs, we have demonstrated that the PCNA promoter can be transactivated by Tax. The smallest construct that was activated did not include the ATF/CRE binding site at nucleotide 2 50, and mutations in the ATF/CRE element in the context of a larger promoter were still activated by Tax. In addition, a Tax mutant that is defective for activation of the CRE pathway retained the ability to activate the 2 397 promoter construct.

Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia. The transforming ability of Tax, the viral oncoprotein, is believed to depend on interactions with cell cycle regulators and on transactivation of genes that control cellular proliferation, including proliferating cell nuclear antigen (PCNA), a cofactor associated with DNA replication and repair. Tax associates with cellular transcription factors to alter their affinity for cognate DNA elements, leading to increased or decreased transcription from that promoter. Although it has been demonstrated that Tax transactivates the PCNA promoter, the mechanism of transcriptional activation is unknown. Here we report a cellular complex that binds specifically to a novel site within the minimal Tax-responsive element of the TATAA-less PCNA pro- moter. Mutation at this binding site or Tax expression inhibited complex formation and increased promoter activity, suggesting that the complex is a transcriptional repressor. The activation of PCNA gene expression by Tax and consequential decrease in nucleotide excision repair mediated by PCNA overexpression could con- tribute to the reduced DNA repair capacity and genomic instability observed in HTLV-1-infected cells.

J Clin Invest. 1994;93(6):2351-2356. https://doi.org/10.1172/JCI117240. We have used antisense phosphorothioate oligonucleotides to define the role played by proliferating cell nuclear antigen (PCNA) in neointimal accumulation of smooth muscle cells in a rat carotid artery injury model. The short-term extraluminal delivery of 250 nmol of

The transforming region of adenovirus (El) stimulates expression of a reporter construct linked to the promoter for the human proliferating cell nuclear antigen (PCNA) gene in a cotransf[r]

Dovepress Yin et al Proliferating cell nuclear antigen (PCNA) was originally discovered in 1978 by Miyachi et al 11 as the antigen to an autoimmune antibody in the sera of patients with systemic lupus erythematosus. 12 It was initially considered to be expressed during cell proliferation, with peak expression occurring during late G1 and S phases. 13,14 However, in recent decades, PCNA has been shown to act as a molecular platform that coordinates a wide range of processes involved in genome maintenance, duplication, transmission, and cell- cycle regulation. 15,16 Because cell proliferation is a require- ment for tumor progression, and owing to the indispensable function of PCNA in cell proliferation, much attention has been paid to the role of PCNA in tumors. 17 Indeed, PCNA was found to be involved in the prognosis of cancer patients, including those with nasopharyngeal carcinoma, lung cancer, prostate carcinoma, and gastric carcinoma. 18–21

ABSTRACT The mismatch repair (MMR) system is critical not only for the repair of DNA replication errors, but also for the regulation of mitotic and meiotic recombination processes. In a manner analogous to its ability to remove replication errors, the MMR system can remove mismatches in heteroduplex recombination intermediates to generate gene conversion events. Alternatively, such mismatches can trigger an MMR- dependent antirecombination activity that blocks the completion of recombination, thereby limiting interactions between diverged sequences. In Saccharomyces cerevisiae, the MMR proteins Msh3, Msh6, and Mlh1 interact with proliferating cell nuclear antigen (PCNA), and mutations that disrupt these interactions result in a mutator phenotype. In addition, some mutations in the PCNA-encoding POL30 gene increase mutation rates in an MMR-dependent manner. In the current study, pol30, mlh1, and msh6 mutants were used to examine whether MMR–PCNA interactions are similarly important during mitotic and meiotic re- combination. We find that MMR–PCNA interactions are important for repairing mismatches formed dur- ing meiotic recombination, but play only a relatively minor role in regulating the fidelity of mitotic recombination.

My aim is to agitate and disturb people. I’m not selling bread, I’m selling yeast. M iguel de U namuno ABSTRACT Among replication mutations that destabilize CAG repeat tracts, mutations of RAD27, encoding the flap endonuclease, and CDC9, encoding DNA ligase I, increase the incidence of repeat tract expansions to the greatest extent. Both enzymes bind to proliferating cell nuclear antigen (PCNA). To understand whether weakening their interactions leads to CAG repeat tract expansions, we have employed alleles named rad27-p and cdc9-p that have orthologous alterations in their respective PCNA interaction peptide (PIP) box. Also, we employed the PCNA allele pol30-90, which has changes within its hydrophobic pocket that interact with the PIP box. All three alleles destabilize a long CAG repeat tract and yield more tract contractions than expansions. Combining rad27-p with cdc9-p increases the expansion frequency above the sum of the numbers recorded in the individual mutants. A similar additive increase in tract expansions occurs in the rad27-p pol30-90 double mutant but not in the cdc9-p pol30-90 double mutant. The frequency of contractions rises in all three double mutants to nearly the same extent. These results suggest that PCNA mediates the entry of the flap endonuclease and DNA ligase I into the process of Okazaki fragment joining, and this ordered entry is necessary to prevent CAG repeat tract expansions.

Int J De" Biol 38 491 497 (1994) 491 Original Article Expression of proliferating cell nuclear antigen in the mouse germ line and surrounding somatic cells suggests both proliferation dependent and in[.]

The genome is constantly damaged by intracellular and extracellular factors. At sites of DNA damage, replication forks are stalled, leading to monoubiquitination of proliferating cell nuclear antigen (PCNA). Monoubiquitination of PCNA promotes the switch from regular high-fidelity polymerases to Y-family polymerases for bypassing damaged DNA. Prolonged replication by these polymerases may lead to increased mutagenesis, so tight regulation of this process is required. ATAD5 recruits a deubiquitinase complex consisting of ubiquitin-specific protease 1 (USP1) and USP1- associated factor 1 (UAF1) to control PCNA monoubiquitination. The mechanism by which ATAD5 and PCNA interact has been previously unexplored. We show through biochemical and structural studies that ATAD5 contains a non-canonical PCNA- interacting protein motif that interacts with PCNA in the low µM range. Our structural studies indicate that the binding of ATAD5’s PIP Box to PCNA is topologically conserved with respect to canonical PIP Boxes from other proteins. Furthermore, we detected we interactions between ATAD5’s and UAF1’s protein interacting motifs. This suggests that ATAD5 acts as an adapter between PCNA and the UAF1-USP1 deubiquitinase complex.

1 Laboratory for Reproductive Immunology, Hospital and Institute of Obstetrics and Gynecology, Fudan University Shanghai Medical College, Shanghai 200011, China; 2 IVF Center, Hospital of Obstetrics and Gynecology, Fudan University Shanghai Medical College, Shanghai 200011, China. * Equal contributors. Received August 10, 2013; Accepted September 5, 2013; Epub September 15, 2013; Published October 1, 2013 Abstract: Our previous studies have demonstrated that cyclosporin A (CsA) promotes the proliferation and migra- tion of human trophoblasts via the mitgen-activated protein kinase-3/1 (MAPK3/1) pathway. In the present study, we further investigated the role of nuclear factor (NF)-κB in the CsA-induced trophoblast proliferating cell nuclear antigen (PCNA) expression and migration, and its relationship to MAPK3/1 signal. Flow cytometry was used to analyze the expression of PCNA in trophoblasts. The migration of human primary trophoblasts was determined by wound-healing assay and transwell migration assay. Western blot analysis was performed to evaluate the activation of NF-κB p65 and NF-κB inhibitory protein I-κB in human trophoblasts. We found that treatment with CsA promotes PCNA expression and migration of human trophoblast in a dose-associated manner. Blocking of the MAPK3/1 sig- nal abrogated the enhanced PCNA expression and migration in trophoblasts by CsA. In addition, CsA increased the phosphorylation of NF-κB p65 and the inhibitor I-κB in human trophoblasts in a time-related manner. Pretreatment with MAPK3/1 inhibitor U0126 abrogated the phosphorylation of NF-κB p65 and I-κB. Accordingly, the CsA-induced enhancement of PCNA expression and migration in trophoblasts was also decreased. This CsA-induced enhance- ment in the expression and migration of trophoblasts was abolished by pretreatment with pyrrolidine dithiocarba- mate, a specific NF-κB inhibitor. Thus, our results suggest that CsA promotes PCNA expression and migration of human trophoblasts via MAPK-mediated NF-κB activation.

C ELLULAR maintenance of genomic integrity is essential for the continued viability of all organ- isms. The fidelity of DNA replication has to be maintained and DNA insults have to be repaired to ensure that deleterious mutations are not passed on to progeny or cause cancerous growth. A number of cel- lular proteins have multiple roles in DNA replication, mutation avoidance, and repair. In Saccharomyces cerevi- siae, the flap endonuclease, proliferating cell nuclear antigen (PCNA), and DNA ligase I encoded by RAD27, POL30, and CDC9, respectively, are all required for proper replication and also function to avoid mutation and to facilitate repair.

ABSTRACT The rev6-1 allele was isolated in a screen for mutants deficient for UV-induced reversion of the frameshift mutation his4-38. Preliminary testing showed that the rev6-1 mutant was substantially deficient for UV-induced reversion of arg4-17 and ilv1-92 and markedly UV sensitive. Unlike other REV genes, which encode DNA polymerases and an associated subunit, REV6 has been found to be identical to POL30, which encodes proliferating cell nuclear antigen (PCNA), the subunit of the homotrimeric sliding clamp, in which the rev6-1 mutation produces a G178S substitution. This substitution appears to abolish all DNA damage-tolerance activities normally carried out by the RAD6/RAD18 pathway, including translesion replication by DNA polymerase z/Rev1 and DNA polymerase h, and the error-free, recombination- dependent component of this pathway, but has little effect on the growth rate, suggesting that G178S may prevent ubiquitination of lysine 164 in PCNA. We also find that rev6-1 mutation can be fully com- plemented by a centromere-containing, low copy-number plasmid carrying POL30, despite the presumed occurrence in the mutant of sliding clamp assemblies that contain between one and three G178S PCNA monomers as well as the fully wild-type species.

Proliferating cell nuclear antigen (PCNA), a marker for the G1-S transition in the cell cycle and hence mitogenesis, was detected primarily in the S3 segment of the proximal tubule, with maximal expression at 2 d postischemia. Vimentin, normally present in mesenchymal cells but not epithelial cells, and hence a marker for the state of differentiation, was