scholarly journals The Influence of the Proliferating Cell Nuclear Antigen-interacting Domain of p21CIP1on DNA Synthesis Catalyzed by the Human andSaccharomyces cerevisiaePolymerase δ Holoenzymes

1997 ◽  
Vol 272 (4) ◽  
pp. 2373-2381 ◽  
Author(s):  
Emma Gibbs ◽  
Zvi Kelman ◽  
Jacqueline M. Gulbis ◽  
Mike O'Donnell ◽  
John Kuriyan ◽  
...  
1993 ◽  
Vol 105 (1) ◽  
pp. 69-80 ◽  
Author(s):  
M. Baptist ◽  
J.E. Dumont ◽  
P.P. Roger

In this study, experimental conditions are described that allowed us to follow the fate of the DNA polymerase delta-associated proliferating cell nuclear antigen (PCNA), by immunolabeling during the overall cell cycle. Differences in subcellular localization or the presence of PCNA allowed us to identify each phase of the cell cycle. Using these cell cycle markers in dog thyroid epithelial cells in primary culture, we found unexpected differences in cell cycle kinetics, in response to stimulations through cAMP-dependent and cAMP-independent pathways. These provide a new dimension to the view that the two pathways are largely separate, but co-operate on DNA synthesis initiation. More precisely, thyrotropin (TSH), acting via cAMP, exerts a potent triggering effect on DNA synthesis, associated with a precocious induction of PCNA appearance. This constitutes the major influence of TSH (cAMP) in determining cell cycle progression, which is only partly moderated by TSH-dependent lengthening of S- and G2-phases.


1997 ◽  
Vol 325 (2) ◽  
pp. 435-440 ◽  
Author(s):  
Antonio GOMEZ-MUÑOZ ◽  
Laura M. FRAGO ◽  
Luis ALVAREZ ◽  
Isabel VARELA-NIETO

We found that natural (long-chain) ceramide 1-phosphate can be dispersed into aqueous solution when dissolved in an appropriate mixture of methanol/dodecane (49:1, v/v). This solvent mixture facilitates the interaction of this phosphosphingolipid with cells. Under these conditions, incubation of EGFR T17 fibroblasts with natural ceramide 1-phosphate caused a potent stimulation of DNA synthesis. This effect was accompanied by an increase in the levels of proliferating-cell nuclear antigen. Concentrations of natural ceramide 1-phosphate that stimulated the synthesis of DNA did not inhibit adenylate cyclase activity, nor did they stimulate phospholipase D. Natural ceramide 1-phosphate did not alter the cellular phosphorylation state of tyrosine residues or of mitogen-activated protein kinase. Furthermore, natural ceramide 1-phosphate failed to induce the expression of the proto-oncogenes c-myc and c-fos. Both the stimulation of DNA synthesis and the induction of proliferating-cell nuclear antigen by natural ceramide 1-phosphate were inhibited by natural ceramides. This work suggests that the use of methanol and dodecane to deliver natural ceramide 1-phosphate to cells may be useful for elucidation of the biological function(s) and mechanism(s) of action of ceramide 1-phosphate.


1999 ◽  
Vol 285 (1) ◽  
pp. 259-267 ◽  
Author(s):  
Giovanni Maga ◽  
Zophonı́as O Jónsson ◽  
Manuel Stucki ◽  
Silvio Spadari ◽  
Ulrich Hübscher

2007 ◽  
Vol 189 (15) ◽  
pp. 5652-5657 ◽  
Author(s):  
Kazuo Tori ◽  
Megumi Kimizu ◽  
Sonoko Ishino ◽  
Yoshizumi Ishino

ABSTRACT Proliferating cell nuclear antigen (PCNA) is the sliding clamp that is essential for the high processivity of DNA synthesis during DNA replication. Pyrococcus furiosus, a hyperthermophilic archaeon, has at least two DNA polymerases, polymerase BI (PolBI) and PolD. Both of the two DNA polymerases interact with the archaeal P. furiosus PCNA (PfuPCNA) and perform processive DNA synthesis in vitro. This phenomenon, in addition to the fact that both enzymes display 3′-5′ exonuclease activity, suggests that both DNA polymerases work in replication fork progression. We demonstrated here that both PolBI and PolD functionally interact with PfuPCNA at their C-terminal PIP boxes. The mutant PolBI and PolD enzymes lacking the PIP-box sequence do not respond to the PfuPCNA at all in an in vitro primer extension reaction. This is the first experimental evidence that the PIP-box motif, located at the C termini of the archaeal DNA polymerases, is actually critical for PCNA binding to form a processive DNA-synthesizing complex.


Biochemistry ◽  
2008 ◽  
Vol 47 (50) ◽  
pp. 13354-13361 ◽  
Author(s):  
Bret D. Freudenthal ◽  
S. Ramaswamy ◽  
Manju M. Hingorani ◽  
M. Todd Washington

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