scholarly journals Human DNA Polymerase ε Colocalizes with Proliferating Cell Nuclear Antigen and DNA Replication Late, but Not Early, in S Phase

2001 ◽  
Vol 277 (10) ◽  
pp. 8658-8666 ◽  
Author(s):  
Jill Fuss ◽  
Stuart Linn
1995 ◽  
Vol 269 (3) ◽  
pp. H943-H951 ◽  
Author(s):  
K. Reiss ◽  
W. Cheng ◽  
J. Kajstura ◽  
E. H. Sonnenblick ◽  
L. G. Meggs ◽  
...  

To determine whether the growth of cardiac fibroblasts during development is modulated by the insulin-like growth factor (IGF)-1 receptor (IGF-1R), the expression of IGF-1, IGF-2, and IGF-1R was determined in fibroblasts from fetal and postnatal hearts. The expression of proliferating cell nuclear antigen (PCNA) and DNA polymerase-alpha was also evaluated in combination with the estimation of DNA replication. In comparison with fetal hearts, at postnatal day 21, fibroblast expression of IGF-1R mRNA, IGF-2, PCNA, and DNA polymerase-alpha was reduced by 77, 70, 80, and 86%, respectively. Moreover, IGF-1R protein decreased by 48% at 21 days. Bromodeoxyuridine labeling decreased by 88 and 89% in the left and right ventricle, respectively, at this time. Two different antisense oligodeoxynucleotides to IGF-1R reduced DNA replication by 60 and 44% in fibroblasts in culture. In addition, this intervention markedly attenuated the growth response of fibroblasts to IGF-1 or serum. In conclusion, the IGF-1R system appears to play a major role in the regulation of fibroblast growth in the heart in vivo.


Microbiology ◽  
2009 ◽  
Vol 155 (11) ◽  
pp. 3748-3757 ◽  
Author(s):  
Devanand Kumar ◽  
Neha Minocha ◽  
Kalpana Rajanala ◽  
Swati Saha

DNA replication in eukaryotes is a highly conserved process marked by the licensing of multiple origins, with pre-replication complex assembly in G1 phase, followed by the onset of replication at these origins in S phase. The two strands replicate by different mechanisms, and DNA synthesis is brought about by the activity of the replicative DNA polymerases Pol δ and Pol ϵ. Proliferating cell nuclear antigen (PCNA) augments the processivity of these polymerases by serving as a DNA sliding clamp protein. This study reports the cloning of PCNA from the protozoan Leishmania donovani, which is the causative agent of the systemic disease visceral leishmaniasis. PCNA was demonstrated to be robustly expressed in actively proliferating L. donovani promastigotes. We found that the protein was present primarily in the nucleus throughout the cell cycle, and it was found in both proliferating procyclic and metacyclic promastigotes. However, levels of expression of PCNA varied through cell cycle progression, with maximum expression evident in G1 and S phases. The subnuclear pattern of expression of PCNA differed in different stages of the cell cycle; it formed distinct subnuclear foci in S phase, while it was distributed in a more diffuse pattern in G2/M phase and post-mitotic phase cells. These subnuclear foci are the sites of active DNA replication, suggesting that replication factories exist in Leishmania, as they do in higher eukaryotes, thus opening avenues for investigating other Leishmania proteins that are involved in DNA replication as part of these replication factories.


2004 ◽  
Vol 279 (46) ◽  
pp. 48360-48368 ◽  
Author(s):  
Antonio E. Vidal ◽  
Patricia Kannouche ◽  
Vladimir N. Podust ◽  
Wei Yang ◽  
Alan R. Lehmann ◽  
...  

2020 ◽  
Author(s):  
Prashant Khandagale ◽  
Shweta Thakur ◽  
Narottam Acharya

AbstractDNA polymerase delta (Polδ) is a highly processive essential replicative DNA polymerase. In humans, Polδ holoenzyme consists of p125, p50, p68, and p12 subunits and recently, we have shown that p12 exists as a dimer. Extensive biochemical studies suggest that all the subunits of Polδ interact with the processivity factor proliferating cell nuclear antigen (PCNA) to carry out a pivotal role in genomic DNA replication. While PCNA interaction protein (PIP) motifs in p68, p50 and p12 have been mapped, the PIP in p125, the catalytic subunit of the holoenzyme, remains elusive. Therefore, in this study by using multiple approaches we have conclusively mapped a non-canonical PIP box from residues 999VGGLLAFA1008 in p125, which binds to inter domain-connecting loop of PCNA with high affinity. Collectively, including previous studies, we conclude that similar to S. cerevisiae Polδ, each of the human Polδ subunits possess motif to interact with PCNA and significantly contribute towards the processive nature of this replicative DNA polymerase.


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