What is meant by proliferating cell nuclear antigen?
Proliferating cell nuclear antigen (PCNA) is a DNA clamp that acts as a processivity factor for DNA polymerase δ in eukaryotic cells and is essential for replication.
Where is PCNA found?
PCNA (proliferating cell nuclear antigen) has been found in the nuclei of yeast, plant and animal cells that undergo cell division, suggesting a function in cell cycle regulation and/or DNA replication.
What is PCNA a marker of?
PCNA is a marker for cells in early G1 phase and S phase of the cell cycle. PCNA is found in the nucleus and is a cofactor of DNA polymerase delta, and acts as a homotrimer and helps increase the processing of leading strand synthesis during DNA replication.
What is the function of RFC in eukaryotic replication?
The primary role of RFC in DNA synthesis is to load PCNA onto DNA templates for processive DNA synthesis by the eukaryotic replicative DNA polymerases.
What does ki67 stand for?
The Ki-67 percentage score is defined as the percentage of positively stained tumor cells among the total number of malignant cells assessed .
What is the role of PCNA in DNA replication?
The best understood function of PCNA, to date, is its role in DNA replication. PCNA plays an essential role in DNA replication as the auxillary protein (processi- tivity factor) of Polδ, the enzyme responsible for the replication of the chromosomal DNA (Figure 2). PCNA is also the processivity factor of Polε.
What is PCNA ring?
Proliferating cell nuclear antigen (PCNA), the eukaryotic DNA sliding clamp, forms a ring-shaped homo-trimer that encircles double-stranded DNA. This protein is best known for its ability to confer high processivity to replicative DNA polymerases.
What does PCNA measure?
Histological assessment of specific features at the invading front of oral squamous cell carcinomas has shown to provide accurate and reproducible prognostic information. Proliferating cell nuclear antigen (PCNA) is a nuclear marker known to reflect cell turnover and may be used as a marker for tumour aggressiveness.
What is proliferating cell nuclear antigen?
Proliferating cell nuclear antigen is encoded by a single gene, is approximately 634 base pairs in size, has a molecular weight of 36 kDa, and in its active form is a trimer.
Which proteins interact with proliferating cell nuclear antigen (PCNA)?
Proteins interacting with PCNA via APIM include human AlkB homologue 2, TFIIS-L, TFII-I, Rad51B, XPA, ZRANB3, and FBH1. Antibodies against proliferating cell nuclear antigen (PCNA) or monoclonal antibody termed Ki-67 can be used for grading of different neoplasms, e.g. astrocytoma.
Does p57Kip2 require binding to proliferating cell nuclear antigen?
“Suppression of cell transformation by the cyclin-dependent kinase inhibitor p57KIP2 requires binding to proliferating cell nuclear antigen”. Proc. Natl. Acad. Sci. U.S.A. 95 (4): 1392–7. Bibcode: 1998PNAS…95.1392W. doi: 10.1073/pnas.95.4.1392. PMC 19016. PMID 9465025. ^ Rountree MR, Bachman KE, Baylin SB (July 2000).
Does polyubiquitination of proliferating cell nuclear antigen by HLTF and SHPRH prevent genomic instability?
“Polyubiquitination of proliferating cell nuclear antigen by HLTF and SHPRH prevents genomic instability from stalled replication forks”. Proc. Natl. Acad. Sci. U.S.A. 105 (34): 12411–6. Bibcode: 2008PNAS..10512411M. doi: 10.1073/pnas.0805685105. PMC 2518831. PMID 18719106.