scholarly journals Transcriptional and posttranscriptional control of c-fos gene expression in human monocytes.

1988 ◽  
Vol 8 (1) ◽  
pp. 340-346 ◽  
Author(s):  
E Sariban ◽  
R Luebbers ◽  
D Kufe
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Phorbol Ester ◽  
Fold Increase ◽  
Transient Increase ◽  
Mrna Levels ◽  
Human Monocytes ◽  
Posttranscriptional Control ◽  
Sense Strand ◽  
The Stability

We examined the mechanisms that are responsible for the regulation of c-fos gene expression in human monocytes. Levels of c-fos mRNA were low or undetectable in resting monocytes. Results of run-on transcription assays, however, demonstrated that both the first two and last two exons of the c-fos gene were transcribed at similar rates, and that only the sense strand of this gene was transcribed. These findings suggest that the level of c-fos transcripts in resting human monocytes is controlled at a posttranscriptional level. Activation of resting monocytes with phorbol ester was associated with a rapid and transient increase in c-fos mRNA levels. This increase in c-fos transcripts was related to an enhanced rate of c-fos transcription. Moreover, exposure of resting monocytes to inhibitors of protein synthesis induced (i) a rapid and marked (300-fold) increase in c-fos mRNA levels, despite only a 9-fold increase in c-fos transcription, and (ii) a prolongation of the half-life of c-fos mRNA. Thus, while posttranscriptional control was responsible for the down-regulation of c-fos transcripts in both resting and activated human monocytes, transcriptional mechanisms were responsible for the transient increase in c-fos expression induced by phorbol ester. Furthermore, the marked increases in c-fos mRNA associated with inhibition of protein synthesis were regulated by both transcriptional and posttranscriptional mechanisms. These findings may be related to recent observations which indicate that both positive and negative factors transcriptionally regulate c-fos gene expression and that sequences found in the 3'-untranslated region of the c-fos mRNA are responsible for the stability of this transcript.

Transcriptional and posttranscriptional control of c-fos gene expression in human monocytes

1988 ◽  
Vol 8 (1) ◽  
pp. 340-346
Author(s):  
E Sariban ◽  
R Luebbers ◽  
D Kufe
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Phorbol Ester ◽  
Fold Increase ◽  
Transient Increase ◽  
Mrna Levels ◽  
Human Monocytes ◽  
Posttranscriptional Control ◽  
Sense Strand ◽  
The Stability

We examined the mechanisms that are responsible for the regulation of c-fos gene expression in human monocytes. Levels of c-fos mRNA were low or undetectable in resting monocytes. Results of run-on transcription assays, however, demonstrated that both the first two and last two exons of the c-fos gene were transcribed at similar rates, and that only the sense strand of this gene was transcribed. These findings suggest that the level of c-fos transcripts in resting human monocytes is controlled at a posttranscriptional level. Activation of resting monocytes with phorbol ester was associated with a rapid and transient increase in c-fos mRNA levels. This increase in c-fos transcripts was related to an enhanced rate of c-fos transcription. Moreover, exposure of resting monocytes to inhibitors of protein synthesis induced (i) a rapid and marked (300-fold) increase in c-fos mRNA levels, despite only a 9-fold increase in c-fos transcription, and (ii) a prolongation of the half-life of c-fos mRNA. Thus, while posttranscriptional control was responsible for the down-regulation of c-fos transcripts in both resting and activated human monocytes, transcriptional mechanisms were responsible for the transient increase in c-fos expression induced by phorbol ester. Furthermore, the marked increases in c-fos mRNA associated with inhibition of protein synthesis were regulated by both transcriptional and posttranscriptional mechanisms. These findings may be related to recent observations which indicate that both positive and negative factors transcriptionally regulate c-fos gene expression and that sequences found in the 3'-untranslated region of the c-fos mRNA are responsible for the stability of this transcript.

Posttranscriptional stabilization of c-fms mRNA by a labile protein during human monocytic differentiation

1989 ◽  
Vol 9 (2) ◽  
pp. 769-775
Author(s):  
B Weber ◽  
J Horiguchi ◽  
R Luebbers ◽  
M Sherman ◽  
D Kufe
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Half Life ◽  
Mrna Levels ◽  
Human Monocytes ◽  
Monocytic Differentiation ◽  
Transmembrane Glycoprotein ◽  
Inhibition Of Protein Synthesis ◽  
Monocytic Lineage ◽  
Posttranscriptional Level

The c-fms proto-oncogene encodes a transmembrane glycoprotein that is closely related or identical to the receptor for the monocyte colony-stimulating factor CSF-1. The present studies examined the mechanisms responsible for the regulation of c-fms gene expression during human monocytic differentiation. Levels of c-fms mRNA were undetectable in HL-60 promyelocytic leukemia cells, while 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced monocytic differentiation of these cells was associated with the appearance of these transcripts. Run-on transcription assays demonstrated that the c-fms gene was transcriptionally active in uninduced HL-60 cells and that the rate of transcription was unchanged after TPA treatment. These findings suggested that c-fms mRNA levels in HL-60 cells are controlled by posttranscriptional mechanisms. The half-life of c-fms transcripts in TPA-induced HL-60 cells was found to be at least 6 h, while inhibition of protein synthesis with cycloheximide (CHX) decreased this half-life to 4 h. Moreover, inhibition of protein synthesis was associated with decreases in c-fms mRNA levels and a block in the induction of c-fms transcripts by TPA. These findings indicated that the c-fms transcript is stabilized by a labile protein. In contrast to HL-60 cells, c-fms mRNA is constitutively expressed in resting human monocytes and is down-regulated by treatment of these cells with TPA. Run-on assays demonstrated that TPA-induced downregulation of c-fms mRNA levels in monocytes occurred at the posttranscriptional level. Moreover, the results demonstrate that levels of c-fms mRNA are regulated posttranscriptionally by a labile protein. In this regard, the half-life of the c-fms transcript was 6.1 h in monocytes, while treatment of these cells with CHX decreased the half-life to 30 min. Furthermore, this effect of CHX occurred in the absence of changes in the rate of c-fms gene transcription. Together, these findings indicate that c-fms gene expression is regulated at a posttranscriptional level both in HL-60 cells induced to differentiate along the monocytic lineage and in human monocytes. The findings also indicate that levels of c-fms mRNA are regulated by the synthesis of a labile protein which is involved in stabilization of the c-fms transcript.

Transcriptional and posttranscriptional regulation of CSF-1 gene expression in human monocytes

1988 ◽  
Vol 8 (9) ◽  
pp. 3951-3954
Author(s):  
J Horiguchi ◽  
E Sariban ◽  
D Kufe
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Gene Transcription ◽  
Posttranscriptional Regulation ◽  
Drug Exposure ◽  
Actinomycin D ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Human Monocytes ◽  
Synthesis Inhibitor

Regulation of CSF-1 gene expression was investigated in human monocytes. CSF-1 transcripts were at low or undetectable levels in resting monocytes. However, in monocytes treated with 12-O-tetradecanoylphorbol-13-acetate (TPA), CSF-1 mRNA was increased by 3 h and reached maximal levels by 12 h of drug exposure. When nuclear run-on assays were used, CSF-1 gene transcription was also at low or undetectable levels in resting monocytes but was activated after TPA exposure. TPA-treated monocytes exposed to actinomycin D further demonstrated that the half-life of the CSF-1 mRNA is 0.9 h. The results also demonstrated that the protein synthesis inhibitor, cycloheximide (CHX), increases CSF-1 mRNA levels in both resting and TPA-treated monocytes. These effects of CHX occurred in the absence of detectable increases in CSF-1 gene transcription. Moreover, treatment of monocytes with CHX and actinomycin D demonstrated that inhibition of protein synthesis is associated with stabilization of the CSF-1 transcript. Taken together, these findings indicated that CSF-1 gene expression is controlled at both transcriptional and posttranscriptional levels in human monocytes.

scholarly journals Transcriptional and posttranscriptional regulation of CSF-1 gene expression in human monocytes.

1988 ◽  
Vol 8 (9) ◽  
pp. 3951-3954 ◽  
Author(s):  
J Horiguchi ◽  
E Sariban ◽  
D Kufe
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Gene Transcription ◽  
Posttranscriptional Regulation ◽  
Drug Exposure ◽  
Actinomycin D ◽  
Protein Synthesis Inhibitor ◽  
Mrna Levels ◽  
Human Monocytes ◽  
Synthesis Inhibitor

Regulation of CSF-1 gene expression was investigated in human monocytes. CSF-1 transcripts were at low or undetectable levels in resting monocytes. However, in monocytes treated with 12-O-tetradecanoylphorbol-13-acetate (TPA), CSF-1 mRNA was increased by 3 h and reached maximal levels by 12 h of drug exposure. When nuclear run-on assays were used, CSF-1 gene transcription was also at low or undetectable levels in resting monocytes but was activated after TPA exposure. TPA-treated monocytes exposed to actinomycin D further demonstrated that the half-life of the CSF-1 mRNA is 0.9 h. The results also demonstrated that the protein synthesis inhibitor, cycloheximide (CHX), increases CSF-1 mRNA levels in both resting and TPA-treated monocytes. These effects of CHX occurred in the absence of detectable increases in CSF-1 gene transcription. Moreover, treatment of monocytes with CHX and actinomycin D demonstrated that inhibition of protein synthesis is associated with stabilization of the CSF-1 transcript. Taken together, these findings indicated that CSF-1 gene expression is controlled at both transcriptional and posttranscriptional levels in human monocytes.

scholarly journals Posttranscriptional stabilization of c-fms mRNA by a labile protein during human monocytic differentiation.

1989 ◽  
Vol 9 (2) ◽  
pp. 769-775 ◽  
Author(s):  
B Weber ◽  
J Horiguchi ◽  
R Luebbers ◽  
M Sherman ◽  
D Kufe
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Half Life ◽  
Mrna Levels ◽  
Human Monocytes ◽  
Monocytic Differentiation ◽  
Transmembrane Glycoprotein ◽  
Inhibition Of Protein Synthesis ◽  
Monocytic Lineage ◽  
Posttranscriptional Level

The c-fms proto-oncogene encodes a transmembrane glycoprotein that is closely related or identical to the receptor for the monocyte colony-stimulating factor CSF-1. The present studies examined the mechanisms responsible for the regulation of c-fms gene expression during human monocytic differentiation. Levels of c-fms mRNA were undetectable in HL-60 promyelocytic leukemia cells, while 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced monocytic differentiation of these cells was associated with the appearance of these transcripts. Run-on transcription assays demonstrated that the c-fms gene was transcriptionally active in uninduced HL-60 cells and that the rate of transcription was unchanged after TPA treatment. These findings suggested that c-fms mRNA levels in HL-60 cells are controlled by posttranscriptional mechanisms. The half-life of c-fms transcripts in TPA-induced HL-60 cells was found to be at least 6 h, while inhibition of protein synthesis with cycloheximide (CHX) decreased this half-life to 4 h. Moreover, inhibition of protein synthesis was associated with decreases in c-fms mRNA levels and a block in the induction of c-fms transcripts by TPA. These findings indicated that the c-fms transcript is stabilized by a labile protein. In contrast to HL-60 cells, c-fms mRNA is constitutively expressed in resting human monocytes and is down-regulated by treatment of these cells with TPA. Run-on assays demonstrated that TPA-induced downregulation of c-fms mRNA levels in monocytes occurred at the posttranscriptional level. Moreover, the results demonstrate that levels of c-fms mRNA are regulated posttranscriptionally by a labile protein. In this regard, the half-life of the c-fms transcript was 6.1 h in monocytes, while treatment of these cells with CHX decreased the half-life to 30 min. Furthermore, this effect of CHX occurred in the absence of changes in the rate of c-fms gene transcription. Together, these findings indicate that c-fms gene expression is regulated at a posttranscriptional level both in HL-60 cells induced to differentiate along the monocytic lineage and in human monocytes. The findings also indicate that levels of c-fms mRNA are regulated by the synthesis of a labile protein which is involved in stabilization of the c-fms transcript.

scholarly journals Posttranscriptional regulation of hsp70 expression in human cells: effects of heat shock, inhibition of protein synthesis, and adenovirus infection on translation and mRNA stability.

1987 ◽  
Vol 7 (12) ◽  
pp. 4357-4368 ◽  
Author(s):  
N G Theodorakis ◽  
R I Morimoto
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Posttranscriptional Regulation ◽  
High Efficiency ◽  
Hsp70 Expression ◽  
Mrna Levels ◽  
Protein Synthesis Inhibitors ◽  
Hsp70 Mrna ◽  
Infected Cells ◽  
The Stability

We have examined the posttranscriptional regulation of hsp70 gene expression in two human cell lines, HeLa and 293 cells, which constitutively express high levels of HSP70. HSP70 mRNA translates with high efficiency in both control and heat-shocked cells. Therefore, heat shock is not required for the efficient translation of HSP70 mRNA. Rather, the main effect of heat shock on translation is to suppress the translatability of non-heat shock mRNAs. Heat shock, however, has a marked effect on the stability of HSP70 mRNA; in non-heat-shocked cells the half-life of HSP70 mRNA is approximately 50 min, and its stability increases at least 10-fold upon heat shock. Moreover, HSP70 mRNA is more stable in cells treated with protein synthesis inhibitors, suggesting that a heat shock-sensitive labile protein regulates its turnover. An additional effect on posttranscriptional regulation of hsp70 expression can be found in adenovirus-infected cells, in which HSP70 mRNA levels decline precipititously late during infection although hsp70 transcription continues unabated.

scholarly journals Differential regulation of mRNA fate by the human Ccr4-Not complex is driven by coding sequence composition and mRNA localization

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sarah L. Gillen ◽  
Chiara Giacomelli ◽  
Kelly Hodge ◽  
Sara Zanivan ◽  
Martin Bushell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Mrna Stability ◽  
Mrna Localization ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Translational Efficiency ◽  
Mrna Levels ◽  
Control Of Gene Expression ◽  
Mrna Fate

Abstract Background Regulation of protein output at the level of translation allows for a rapid adaptation to dynamic changes to the cell’s requirements. This precise control of gene expression is achieved by complex and interlinked biochemical processes that modulate both the protein synthesis rate and stability of each individual mRNA. A major factor coordinating this regulation is the Ccr4-Not complex. Despite playing a role in most stages of the mRNA life cycle, no attempt has been made to take a global integrated view of how the Ccr4-Not complex affects gene expression. Results This study has taken a comprehensive approach to investigate post-transcriptional regulation mediated by the Ccr4-Not complex assessing steady-state mRNA levels, ribosome position, mRNA stability, and protein production transcriptome-wide. Depletion of the scaffold protein CNOT1 results in a global upregulation of mRNA stability and the preferential stabilization of mRNAs enriched for G/C-ending codons. We also uncover that mRNAs targeted to the ER for their translation have reduced translational efficiency when CNOT1 is depleted, specifically downstream of the signal sequence cleavage site. In contrast, translationally upregulated mRNAs are normally localized in p-bodies, contain disorder-promoting amino acids, and encode nuclear localized proteins. Finally, we identify ribosome pause sites that are resolved or induced by the depletion of CNOT1. Conclusions We define the key mRNA features that determine how the human Ccr4-Not complex differentially regulates mRNA fate and protein synthesis through a mechanism linked to codon composition, amino acid usage, and mRNA localization.

Effect of protein synthesis inhibition on gene expression during early development of Dictyostelium discoideum

1988 ◽  
Vol 8 (1) ◽  
pp. 10-16
Author(s):  
C K Singleton ◽  
S S Manning ◽  
Y Feng
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Dictyostelium Discoideum ◽  
Cdna Libraries ◽  
Mrna Levels ◽  
Protein Synthesis Inhibition ◽  
Mutant Strains ◽  
V Genes ◽  
Steady State Levels ◽  
Development Proceeds

Several genes which are deactivated on the initiation of development of Dictyostelium discoideum were identified by differential screening of various cDNA libraries. These genes have in common a decrease in the steady-state levels of their corresponding mRNAs on the onset of development and as development proceeds. When development was carried out in the absence of protein synthesis by inhibition with cycloheximide, the decrease in mRNA levels for most genes (V genes) was normal or slightly accelerated. For about 5% of the genes (H genes), however, cycloheximide caused an apparent induction of expression, as revealed by a slight or dramatic increase in mRNA levels, instead of the normal decrease. This effect was due to inhibition of protein synthesis and not to cycloheximide per se. The induction was found to be due to an enhancement of the transcription rate; normal rates of transcription for the H genes were dependent on continued protein synthesis during vegetative growth and development. Thus, two general regulatory classes exist for deactivation of gene expression on initiation of development, one of which is dependent on and one of which is independent of protein synthesis. Analysis of expression of these genes in mutant strains which are aggregation deficient allowed the classes to be subdivided further. Taken together, these characterizations allow several distinct regulatory mechanisms to be identified that are involved in the deactivation of gene expression on the onset of development in D. discoideum.

Serum transcriptionally regulates Na(+)-K(+)-ATPase gene expression in vascular smooth muscle cells

1997 ◽  
Vol 273 (3) ◽  
pp. C1088-C1099 ◽  
Author(s):  
J. Nemoto ◽  
S. Muto ◽  
A. Ohtaka ◽  
K. Kawakami ◽  
Y. Asano
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Atpase Activity ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Fold Increase ◽  
Mrna Levels ◽  
Subunit Protein ◽  
Mrna Induction

The present study was designed to examine the effects of serum on Na(+)-K(+)-ATPase alpha 1- and beta 1-subunit gene expression in cultured vascular smooth muscle cells (VSMC) from rat thoracic aortas. Addition of 10% serum to VSMC for 24 h increased Na(+)-K(+)-ATPase activity 1.5-fold and alpha 1- and beta 1-subunit protein levels 1.9-fold. Serum (10%) caused a 3.5-fold increase in alpha 1-mRNA levels and a 6.7-fold increase in beta 1-mRNA levels, with peak elevations at 12 h. The protein synthesis inhibitor cycloheximide abolished serum-mediated beta 1-mRNA induction but did not affect serum-mediated alpha 1-mRNA induction. Protein kinase C (PKC) inhibitors (staurosporine A or calphostin C) or tyrosine kinase (TK) inhibitors (genistein or herbimycin A) significantly reduced serum-mediated beta 1-mRNA induction but had no effect on serum-mediated alpha 1-mRNA induction. Transfection experiments with the 5'-flanking sequences of the alpha 1- or beta 1-subunit genes linked to the luciferase reporter gene revealed that 10% serum caused 2.8- and 6.5-fold increases in luciferase activity, respectively. Among growth factors, only basic fibroblast growth factor (FGF) enhanced luciferase activities for the alpha 1- and beta 1-subunit genes. We conclude that 1) serum stimulates alpha 1- and beta 1-mRNA expression, alpha 1- and beta 1-subunit protein accumulation, and Na(+)-K(+)-ATPase activity; 2) serum-mediated beta 1-mRNA induction partly requires de novo synthesis of intermediate regulatory proteins and activation of PKC and TK, whereas serum-mediated alpha 1-mRNA induction occurs through PKC- and TK-independent mechanisms; 3) the 5'-flanking regions of the alpha 1- and beta 1-subunit genes are serum responsive; and 4) FGF mimics stimulatory effects of serum on promoter activities for the alpha 1- and beta 1-subunit genes.

scholarly journals Alteration in gene expression of branched-chain keto acid dehydrogenase kinase but not in gene expression of its substrate in the liver of clofibrate-treated rats

1996 ◽  
Vol 317 (2) ◽  
pp. 411-417 ◽  
Author(s):  
Harbhajan S. PAUL ◽  
Wei-Qun LIU ◽  
Siamak A. ADIBI
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
Fold Increase ◽  
Branched Chain Amino Acids ◽  
The Other ◽  
Mrna Levels ◽  
Keto Acid ◽  
Protein Mass ◽  
Acid Dehydrogenase ◽  
Branched Chain

We previously showed that the oxidation of branched-chain amino acids is increased in rats treated with clofibrate [Paul and Adibi (1980) J. Clin. Invest. 65, 1285–1293]. Two subsequent studies have reported contradictory results regarding the effect of clofibrate treatment on gene expression of branched-chain keto acid dehydrogenase (BCKDH) in rat liver. Furthermore, there has been no previous study of the effect of clofibrate treatment on gene expression of BCKDH kinase, which regulates the activity of BCKDH by phosphorylation. The purpose of the present study was to investigate the above issues. Clofibrate treatment for 2 weeks resulted in (a) a 3-fold increase in the flux through BCKDH in mitochondria isolated from rat liver, and (b) a modest but significant increase in the activity of BCKDH. However, clofibrate treatment had no significant effect on the mass of E1α, E1β, and E2 subunits of BCKDH or the abundance of mRNAs encoding these subunits. On the other hand, clofibrate treatment significantly reduced the activity, the protein mass and the mRNA levels of BCKDH kinase in the liver. In contrast to the results obtained in liver, clofibrate treatment had no significant effect on any of these parameters of BCKDH kinase in the skeletal muscle. In conclusion, our results show that clofibrate treatment increases the activity of BCKDH in the liver and the mechanism of this effect is the inhibition of gene expression of the BCKDH kinase.

Sign in / Sign up

Export Citation Format

Share Document