scholarly journals Correlation between a specific molecular weight form of plasminogen activator and metabolic activity of 3T3 cells.

1981 ◽  
Vol 90 (3) ◽  
pp. 721-726 ◽  
Author(s):  
S Jaken ◽  
P H Black
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Growth Stimulation ◽  
Transformed Cells ◽  
3T3 Cells ◽  
Myristate Acetate ◽  
Quiescent Cells ◽  
Predominant Form ◽  
Molecular Weight Form ◽  
Stimulation Of

In quiescent cultures of 3T3 cells, plasminogen activator (PA) is found predominantly as a 75,000 dalton species. When quiescent cells are exposed to mitogenic agents such as phorbol myristate acetate, Ca++, or 25% serum, the absolute levels of PA in cell lysates may either increase or decrease. However, a consistent observation is that in the stimulated cultures PA is found predominantly as a 49,000 dalton species. This also is the predominant form of PA in growing and transformed cells. Concomitant with the mitogen-induced stimulation of the 49,000 dalton PA in quiescent cultures is a change in morphology to one that is characteristic of growing and transformed cells. The data suggest that PA is not operative in causing the morphological change that occurs with activation; however, the 49,000 dalton PA in particular is closely related to the pleiotypic response accompanying growth stimulation and transformation.

scholarly journals Regulation of plasminogen activator in 3T3 cells: effect of phorbol myristate acetate on subcellular distribution and molecular weight.

1981 ◽  
Vol 90 (3) ◽  
pp. 727-731 ◽  
Author(s):  
S Jaken ◽  
P H Black
Keyword(s):  
Molecular Weight ◽  
Plasma Membrane ◽  
Plasminogen Activator ◽  
Phorbol Myristate Acetate ◽  
Subcellular Distribution ◽  
Tumor Promoter ◽  
3T3 Cells ◽  
Myristate Acetate ◽  
Extracellular Release ◽  
Swiss 3T3

The tumor promoter, phorbol myristate acetate (PMA), stimulates plasminogen activator production and extracellular release in confluent Swiss 3T3 cells. Coordinated with the increased extracellular release is a redistribution of the activity into plasma membrane-enriched fractions and a shift in the predominant molecular weight species from 75,000 to 49,000 daltons. The evidence suggests that PMA induces the formation of the 49,000 dalton species which is preferentially located in plasma membrane-enriched fractions.

Antisense RNA of proto-oncogene c-fos blocks renewed growth of quiescent 3T3 cells

1987 ◽  
Vol 7 (2) ◽  
pp. 639-649
Author(s):  
K Nishikura ◽  
J M Murray
Keyword(s):  
Growth Factor ◽  
Antisense Rna ◽  
Platelet Derived Growth Factor ◽  
3T3 Cells ◽  
Mammary Tumor Virus ◽  
Quiescent Cells ◽  
Mouse Mammary Tumor ◽  
Tumor Virus ◽  
Virus Promoter ◽  
Stimulation Of

Mouse 3T3 cells were transformed with an antisense c-fos gene fused to a mouse mammary tumor virus promoter. In transformants that integrated a large number of antisense c-fos sequences, the usual large increase in c-fos mRNA and protein following stimulation of quiescent cells by platelet-derived growth factor was blocked in the presence of dexamethasone. These cells subsequently also failed to show the stimulation of DNA synthesis normally induced by platelet-derived growth factor. Appropriate expression of c-fos appears to be a prerequisite for reentry of quiescent cells into the cell cycle.

Increased growth stimulation of fibroblasts from diabetics by diabetic serum factors of low molecular weight

1980 ◽  
Vol 37 (2) ◽  
pp. 311-317 ◽  
Author(s):  
T. Koschinsky ◽  
C.E. Bünting ◽  
B. Schwippert ◽  
F.A. Gries
Keyword(s):  
Molecular Weight ◽  
Growth Stimulation ◽  
Low Molecular Weight ◽  
Serum Factors ◽  
Stimulation Of

Studies on the mechanism of Ca2+ stimulation of plasminogen activator synthesis/release by swiss 3T3 cells

1979 ◽  
Vol 100 (3) ◽  
pp. 457-465 ◽  
Author(s):  
Iih-Nan (George) Chou ◽  
Robert Cox ◽  
Paul H. Black
Keyword(s):  
Plasminogen Activator ◽  
3T3 Cells ◽  
Swiss 3T3 ◽  
Stimulation Of

scholarly journals The isocitrate dehydrogenases of Acinetobacter lwoffi. Studies on the regulation of nicotinamide–adenine dinucleotide phosphate-linked isoenzyme

1973 ◽  
Vol 132 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Colin H. Self ◽  
Malcolm G. Parker ◽  
P. David J. Weitzman
Keyword(s):  
Molecular Weight ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Ph Optimum ◽  
Low Concentrations ◽  
Molecular Weight Form ◽  
Metabolic Significance ◽  
Regulatory Sites ◽  
Stimulation Of

Of the two NADP-linked isocitrate dehydrogenases in Acinetobacter lwoffi the higher-molecular-weight form, isoenzyme-II, is reversibly stimulated sixfold by low concentrations of glyoxylate or pyruvate. Kinetic results indicate that this stimulation of activity involves both an increase in Vmax. and a decrease in the apparent Km values for substrates, most markedly that for NADP+. Other changes brought about by glyoxylate or pyruvate include a shift in the pH optimum for activity and an increased stability to inactivation by heat or urea. Mixtures of glyoxylate plus oxaloacetate, known to inhibit isocitrate dehydrogenases from other organisms, produce inhibition of both A. lowffi isoenzymes, and do not reflect the stimulatory specificity of glyoxylate for isoenzyme-II. Isoenzyme-II is also stimulated by AMP and ADP, but the activation by glyoxylate or pyruvate is shown to be quite independent of the adenylate activation. Differential desensitization of the enzyme by urea to the two types of activator further supports the view that the enzyme possesses two distinct allosteric regulatory sites. The metabolic significance of the activations is discussed.

Existence of different Fos/Jun complexes during the G0-to-G1 transition and during exponential growth in mouse fibroblasts: differential role of Fos proteins

1992 ◽  
Vol 12 (11) ◽  
pp. 5015-5023
Author(s):  
K Kovary ◽  
R Bravo
Keyword(s):  
Exponential Growth ◽  
S Phase ◽  
3T3 Cells ◽  
Mouse Fibroblasts ◽  
Quiescent Cells ◽  
Serum Stimulation ◽  
Fos Protein ◽  
Swiss 3T3 ◽  
Stimulation Of

We have determined the different Fos/Jun complexes present in Swiss 3T3 cells either following serum stimulation of quiescent cells or during exponential growth by immunoprecipitation analyses. We have shown that while c-Fos is the major Fos protein associated with the Jun proteins (c-Jun, JunB, and JunD) soon after serum stimulation, at later times Fra-1 and Fra-2 are the predominant Fos proteins associated with the different Jun proteins. During exponential growth, the synthesis of Fra-1 and Fra-2 is maintained at a significant level, in contrast to c-Fos and FosB, which are expressed at very low or undetectable levels. Consequently, Fra-1 and Fra-2 are the main Fos proteins complexed with the Jun proteins in asynchronously growing cells. To determine whether the Fos proteins are differentially required during the G0-to-G1 transition and exponential growth for the entrance into S phase, we microinjected affinity-purified antibodies directed against c-Fos, FosB, Fra-1, and Fra-2. We have found that while the activities of c-Fos and FosB are required mostly during the G0-to-G1 transition, Fra-1 and Fra-2 are involved both in the G0-to-G1 transition and in asynchronous growth.

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