Demonstration of cell cycle kinetics in thyroid primary culture by immunostaining of proliferating cell nuclear antigen: differences in cyclic AMP-dependent and -independent mitogenic stimulations

1993 ◽  
Vol 105 (1) ◽  
pp. 69-80 ◽  
Author(s):  
M. Baptist ◽  
J.E. Dumont ◽  
P.P. Roger
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Primary Culture ◽  
Proliferating Cell Nuclear Antigen ◽  
Cell Cycle Progression ◽  
Nuclear Antigen ◽  
Major Influence ◽  
Cell Cycle Kinetics ◽  
Experimental Conditions ◽  
Proliferating Cell

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.

scholarly journals The distribution pattern of proliferating cell nuclear antigen in the nuclei of Leishmania donovani

Microbiology ◽  
2009 ◽  
Vol 155 (11) ◽  
pp. 3748-3757 ◽  
Author(s):  
Devanand Kumar ◽  
Neha Minocha ◽  
Kalpana Rajanala ◽  
Swati Saha
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Proliferating Cell Nuclear Antigen ◽  
Cell Cycle Progression ◽  
Leishmania Donovani ◽  
Systemic Disease ◽  
S Phase ◽  
Nuclear Antigen ◽  
M Phase ◽  
Proliferating Cell

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.

Growth retardation and dyslymphopoiesis accompanied by G2/M arrest in APEX2-null mice

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4097-4103 ◽  
Author(s):  
Yasuhito Ide ◽  
Daisuke Tsuchimoto ◽  
Yohei Tominaga ◽  
Manabu Nakashima ◽  
Takeshi Watanabe ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Proliferating Cell Nuclear Antigen ◽  
Cell Cycle Progression ◽  
Immunoglobulin M ◽  
Nuclear Antigen ◽  
Wild Type ◽  
Cycle Progression ◽  
Class Switch ◽  
M Phase ◽  
Proliferating Cell

Abstract APEX2/APE2 is a secondary mammalian apurinic/apyrimidinic endonuclease that associates with proliferating cell nuclear antigen (PCNA), and the progression of S phase of the cell cycle is accompanied by its expression. To determine the biologic significance of APEX2, we established APEX2-null mice. These mice were about 80% the size of their wild-type littermates and exhibited a moderate dyshematopoiesis and a relatively severe defect in lymphopoiesis. A significant accumulation of both thymocytes and mitogen-stimulated splenocytes in G2/M phase was seen in APEX2-null mice compared with the wild type, indicating that APEX2 is required for proper cell cycle progression of proliferating lymphocytes. Although APEX2-null mice exhibited an attenuated immune response against ovalbumin in comparison with wild-type mice, they produced both antiovalbumin immunoglobulin M (IgM) and IgG, indicating that class switch recombination can occur even in the absence of APEX2. (Blood. 2004;104: 4097-4103)

Different functional domains of the adenovirus E1A gene are involved in regulation of host cell cycle products

1987 ◽  
Vol 7 (2) ◽  
pp. 821-829
Author(s):  
B Zerler ◽  
R J Roberts ◽  
M B Mathews ◽  
E Moran
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Proliferating Cell Nuclear Antigen ◽  
Nuclear Antigen ◽  
Deletion Mutants ◽  
Terminal Exon ◽  
Adenovirus E1a ◽  
E1a Gene ◽  
Proliferating Cell ◽  
Stimulation Of

We have analyzed the cell cycle effects that different domains of the adenovirus E1A proteins have on quiescent primary BRK cells. Studies with deletion mutants that in combination removed all but the N-terminal 85 amino acids common to both the 12S and 13S proteins suggest that this region may be sufficient for the induction of synthesis of proliferating cell nuclear antigen and the stimulation of DNA synthesis. A second domain also common to the N-terminal exon of the 12S and 13S proteins was required for the induction of mitosis and stimulation of proliferation of primary BRK cells. A virus containing a mutation in this region was still able to stimulate DNA synthesis efficiently. A third domain, unique to the 13S protein, was required for the accelerated activation of the cellular thymidylate synthase gene in a manner similar to the 13S-dependent stimulation of adenovirus early region genes.

scholarly journals Different functional domains of the adenovirus E1A gene are involved in regulation of host cell cycle products.

1987 ◽  
Vol 7 (2) ◽  
pp. 821-829 ◽  
Author(s):  
B Zerler ◽  
R J Roberts ◽  
M B Mathews ◽  
E Moran
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Proliferating Cell Nuclear Antigen ◽  
Nuclear Antigen ◽  
Deletion Mutants ◽  
Terminal Exon ◽  
Adenovirus E1a ◽  
E1a Gene ◽  
Proliferating Cell ◽  
Stimulation Of

We have analyzed the cell cycle effects that different domains of the adenovirus E1A proteins have on quiescent primary BRK cells. Studies with deletion mutants that in combination removed all but the N-terminal 85 amino acids common to both the 12S and 13S proteins suggest that this region may be sufficient for the induction of synthesis of proliferating cell nuclear antigen and the stimulation of DNA synthesis. A second domain also common to the N-terminal exon of the 12S and 13S proteins was required for the induction of mitosis and stimulation of proliferation of primary BRK cells. A virus containing a mutation in this region was still able to stimulate DNA synthesis efficiently. A third domain, unique to the 13S protein, was required for the accelerated activation of the cellular thymidylate synthase gene in a manner similar to the 13S-dependent stimulation of adenovirus early region genes.

scholarly journals Stimulation of DNA synthesis by natural ceramide 1-phosphate

1997 ◽  
Vol 325 (2) ◽  
pp. 435-440 ◽  
Author(s):  
Antonio GOMEZ-MUÑOZ ◽  
Laura M. FRAGO ◽  
Luis ALVAREZ ◽  
Isabel VARELA-NIETO
Keyword(s):  
Dna Synthesis ◽  
Proliferating Cell Nuclear Antigen ◽  
Solvent Mixture ◽  
Mitogen Activated Protein Kinase ◽  
Nuclear Antigen ◽  
Tyrosine Residues ◽  
Mitogen Activated Protein ◽  
Ceramide 1 ◽  
Proliferating Cell ◽  
Stimulation Of

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.

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