scholarly journals The Effects of Inhibitors of Macromolecular Biosynthesis upon the Persistent Rhythm of Luminescence in Gonyaulax

1963 ◽  
Vol 47 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Marlene W. Karakashian ◽  
J. Woodland Hastings
Keyword(s):  
Protein Synthesis ◽  
Nucleic Acid ◽  
Mitomycin C ◽  
Actinomycin D ◽  
Daily Rhythm ◽  
Per Se

Certain inhibitors of nucleic acid and protein synthesis, namely actinomycin D, mitomycin C, and puromycin, have been found to block the expression of a persistent daily rhythm of bioluminescence. The action does not inhibit luminescence per se but rather the rhythmicity. Exposure of the cells to these inhibitors for only a few hours, which might be expected to thereby delay the rhythm by a few hours, does not in fact have this effect. Chloramphenicol and amethopterin do not inhibit the rhythm. It is proposed that the functioning of the clock-like rhythmic mechanism depends upon the cell's normal ability to synthesize RNA.

scholarly journals DIFFERENT LETHAL EFFECTS OF MITOMYCIN C AND ACTINOMYCIN D DURING THE DIVISION CYCLE OF HELA CELLS

1968 ◽  
Vol 38 (3) ◽  
pp. 477-482 ◽  
Author(s):  
Bozidar Djordjevic ◽  
Jae Ho Kim
Keyword(s):  
Protein Synthesis ◽  
Mitomycin C ◽  
Hela Cells ◽  
Actinomycin D ◽  
Potent Inhibitor ◽  
S Phase ◽  
G1 Phase ◽  
Lethal Effects ◽  
Inhibitor Of Protein Synthesis

The lethal actions of mitomycin C and actinomycin D were followed during the division cycle of HeLa cells. The cells were most susceptible to a 2 hr pulse of mitomycin C during the G1 phase, whereas their sensitivity to actinomycin D was most pronounced in the S phase. Posttreatment of the cells with acetoxycycloheximide, a potent inhibitor of protein synthesis, increased the survival (colony-forming ability) of cells treated with mitomycin C but had very little effect on the survival of cells treated with actinomycin D. The significance of these findings is discussed.

Differential effects of actinomycin D on nucleic acid and protein synthesis in rat liver

1968 ◽  
Vol 126 (2) ◽  
pp. 393-398 ◽  
Author(s):  
L. Prosky ◽  
B. Roberts ◽  
R.G. O'Dell ◽  
R.L. Imblum
Keyword(s):  
Protein Synthesis ◽  
Nucleic Acid ◽  
Rat Liver ◽  
Actinomycin D ◽  
Differential Effects

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Lipopolysaccharide-induced sensitization of adenylyl cyclase activity in murine macrophages

2006 ◽  
Vol 290 (1) ◽  
pp. C143-C151 ◽  
Author(s):  
Y. Osawa ◽  
H. T. Lee ◽  
C. A. Hirshman ◽  
D. Xu ◽  
C. W. Emala
Keyword(s):  
Protein Synthesis ◽  
Adenylyl Cyclase ◽  
Actinomycin D ◽  
Inhibitory Effect ◽  
Cytokine Release ◽  
Adenylyl Cyclase Activity ◽  
Phosphorylation State ◽  
Murine Macrophages ◽  
Dependent Pathway ◽  
New Protein

LPS is known to modulate macrophage responses during sepsis, including cytokine release, phagocytosis, and proliferation. Although agents that elevate cAMP reverse LPS-induced macrophage functions, whether LPS itself modulates cAMP and whether LPS-induced decreases in proliferation are modulated via a cAMP-dependent pathway are not known. Murine macrophages (RAW264.7 cells) were treated with LPS in the presence or absence of inhibitors of prostaglandin signaling, protein kinases, CaM, Giproteins, and NF-κB translocation or transcription/translation. LPS effects on CaMKII phosphorylation and the expression of relevant adenylyl cyclase (AC) isoforms were measured. LPS caused a significant dose (5–10,000 ng/ml)- and time (1–8 h)-dependent increase in forskolin-stimulated AC activity that was abrogated by pretreatment with SN50 (an NF-κB inhibitor), actinomycin D, or cycloheximide, indicating that the effect is mediated via NF-κB-dependent transcription and new protein synthesis. Furthermore, LPS decreased the phosphorylation state of CaMKII, and pretreatment with a CaM antagonist attenuated the LPS-induced sensitization of AC. LPS, cAMP, or PKA activation each independently decreased macrophage proliferation. However, inhibition of NF-κB had no effect on LPS-induced decreased proliferation, indicating that LPS-induced decreased macrophage proliferation can proceed via PKA-independent signaling pathways. Taken together, these findings indicate that LPS induces sensitization of AC activity by augmenting the stimulatory effect of CaM and attenuating the inhibitory effect of CaMKII on isoforms of AC that are CaMK sensitive.

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