scholarly journals Regulation of mammalian ribonucleotide reductase R1 mRNA stability is mediated by a ribonucleotide reductase R1 mRNA 3′-untranslated region cis-trans interaction through a protein kinase C-controlled pathway

1994 ◽  
Vol 302 (1) ◽  
pp. 125-132 ◽  
Author(s):  
F Y Chen ◽  
F M Amara ◽  
J A Wright
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Okadaic Acid ◽  
Ribonucleotide Reductase ◽  
Mrna Stability ◽  
Untranslated Region ◽  
Rna Binding ◽  
Kinase C ◽  
The Stability ◽  
Dose Dependent

Ribonucleotide reductase catalyses the reaction that eventually provides the four deoxyribonucleotides required for the synthesis and repair of DNA. U.v.-cross-linking and band-shift experiments have identified in COS 7 monkey cells an approx. 57 kDa ribonucleotide reductase R1 mRNA-binding protein called R1BP, which binds specifically to a 49-nt region of the R1 mRNA 3′-untranslated region (3′UTR). The R1BP-RNA binding activity was down-regulated by the tumour promoters phorbol 12-myristate 13-acetate (PMA; ‘TPA’) and okadaic acid, and up-regulated by the protein kinase C inhibitor staurosporine, in a dose-dependent fashion. Furthermore, staurosporine treatment decreased the stability of R1 and CAT (chloramphenicol acetyltransferase)/R1 hybrid mRNAs, whereas PMA and okadaic acid increased the stability of these messages, in a dose-dependent manner. In contrast, treatment of cells with forskolin, a protein kinase A inhibitor, did not alter either R1BP-RNA binding or R1 mRNA-stability characteristics. Transfectants containing R1 or CAT/R1 cDNA constructs with a deletion of the 49-nt 3′UTR sequence failed to respond in message-stability studies to the effects of PMA, staurosporine or okadaic acid. These observations indicate that a protein kinase C signal pathway regulates ribonucleotide reductase R1 gene expression post-transcriptionally, through a mechanism involving a specific cis-trans interaction at a 49-nt region within the R1 mRNA 3′UTR.

Posttranscriptional regulation of ribonucleotide reductase R1 gene expression is linked to a protein kinase C pathway in mammalian cells

1994 ◽  
Vol 72 (7-8) ◽  
pp. 251-256 ◽  
Author(s):  
Frank Y. Chen ◽  
Francis M. Amara ◽  
Jim A. Wright
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Ribonucleotide Reductase ◽  
Mrna Stability ◽  
Posttranscriptional Regulation ◽  
Signal Pathway ◽  
Kinase C ◽  
Gf 109203X ◽  
Protein Kinase C Inhibitor ◽  
R1 Gene

A rate-limiting reaction in DNA synthesis is catalyzed by ribonucleotide reductase, the enzyme responsible for reducing ribonucleotides to provide the deoxyribonucleotide precursors of DNA. In this study, we have tested the hypothesis that posttranscriptional regulation of ribonucleotide reductase R1 gene expression is controlled by a protein kinase C signal pathway. We show that mouse BALB/c 3T3 fibroblasts treated with the potent and highly specific protein kinase C inhibitor bisindolylmaleimide GF 109203X contain significantly reduced steady-state levels of R1 mRNA and protein. Message half-life studies demonstrate that this is due, at least in part, to a marked decrease in R1 message stability in cells treated with the protein kinase C inhibitor. Furthermore, the protein kinase C signal pathway appears to be specifically involved in this regulation since 8-bromo-cAMP, a modulator of the protein kinase A pathway, had no effect on R1 mRNA levels or stability properties. Cross-linking assays revealed that the binding activity of a R1 mRNA 3′-untranslated region binding protein (R1BP), which was previously shown to be involved in the regulation of R1 mRNA stability, was significantly elevated after treatment of the cells with GF 109203X, in a dose-dependent manner. However, treatment with 8-bromo-cAMP at concentrations up to 2.5 mM did not obviously affect the basic level of the R1BP–RNA interaction. These observations provide a better understanding of the biochemical signals that are critical for the cis–trans interaction-mediated posttranscriptional regulation of ribonucleotide reductase R1 gene expression.Key words: protein kinase C, ribonucleotide reductase, mRNA stability, RNA–protein interaction, bisindolylmaleimide GF 109203X, 8-bromo-cAMP.

scholarly journals Regulation of Nramp1 mRNA stability by oxidants and protein kinase C in RAW264.7 macrophages expressing Nramp1Gly169

2000 ◽  
Vol 351 (3) ◽  
pp. 687-696 ◽  
Author(s):  
William P. LAFUSE ◽  
Gail R. ALVAREZ ◽  
Bruce S. ZWILLING
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Mrna Stability ◽  
Pleiotropic Effects ◽  
Natural Resistance ◽  
Raw264.7 Macrophages ◽  
Kinase C ◽  
Wide Range ◽  
Macrophage Protein ◽  
The Stability

The murine Nramp1 (natural-resistance-associated macrophage protein) locus confers innate resistance against intracellular macrophage pathogens. The gene encodes a transporter molecule, which is rapidly recruited to the phagosome. Nramp1 functions as an iron transporter by transporting iron into the phagosome. Within the phagosome iron mediates anti-microbial killing by hydroxyl radical formation through the iron-catalysed Fenton/Haber–Weiss reaction. In addition to its effects on the growth of intracellular pathogens, Nramp1 exerts a wide range of pleiotropic effects in activated macrophages. One of these pleiotropic effects is the increased stability of a variety of mRNA species, including Nramp1 mRNA. In the present study, the stability of Nramp1 mRNA in Mycobacterium avium infected RAW264.7 macrophages expressing either the Nramp1Gly169 resistant allele or the Nramp1Asp169 susceptible allele was examined. Nramp1 mRNA stability was greater in Nramp1Gly169 macrophages than in Nramp1Asp169 macrophages. The increase in Nramp1 mRNA stability in resistant macrophages was inhibited by antioxidants and protein kinase C (PKC) inhibitors, suggesting that Nramp1 mRNA stability is regulated by an oxidant-generated signalling pathway that requires PKC activity. This was corroborated by treating Nramp1Asp169 macrophages with menadione, which generates reactive oxygen species within cells. Menadione increased Nramp1 mRNA stability to the level observed in resistant macrophages; this increase was also inhibited by a PKC inhibitor. Further, PKC activity was found to be greater in M. avium-infected Nramp1Gly169 macrophages than in infected Nramp1Asp169 macrophages and inhibited by treatment with an antioxidant.

Regulation of oxytocin secretion by the ovine corpus luteum: effect of activators of protein kinase C

1990 ◽  
Vol 124 (2) ◽  
pp. 225-232 ◽  
Author(s):  
J. J. Hirst ◽  
G. E. Rice ◽  
G. Jenkin ◽  
G. D. Thorburn
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Corpus Luteum ◽  
Phospholipase C ◽  
Tissue Slices ◽  
Kinase C ◽  
Luteal Tissue ◽  
Dose Dependent ◽  
Stimulation Of

ABSTRACT The effect of protein kinase C activation and dibutyryl cyclic AMP on oxytocin secretion by ovine luteal tissue slices was investigated. Several putative regulators of luteal oxytocin secretion were also examined. Oxytocin was secreted by luteal tissue slices at a basal rate of 234·4 ± 32·8 pmol/g per h (n = 24) during 60-min incubations.Activators of protein kinase C: phorbol 12,13-dibutyrate (n = 8), phorbol 12-myristate,13-acetate (n = 4) and 1,2-didecanoylglycerol (n = 5), caused a dose-dependent stimulation of oxytocin secretion in the presence of a calcium ionophore (A23187; 0·2 μmol/l). Phospholipase C (PLC; 50–250 units/l) also caused a dose-dependent stimulation of oxytocin secretion by luteal slices. Phospholipase C-stimulated oxytocin secretion was potentiated by the addition of an inhibitor of diacylglycerol kinase (R59 022; n = 4). These data suggest that the activation of protein kinase C has a role in the stimulation of luteal oxytocin secretion. The results are also consistent with the involvement of protein kinase C in PLC-stimulated oxytocin secretion. The cyclic AMP second messenger system does not appear to be involved in the control of oxytocin secretion by the corpus luteum. Journal of Endocrinology (1990) 124, 225–232

scholarly journals Protein kinase C-δ regulates the stability of hypoxia-inducible factor-1α under hypoxia

2007 ◽  
Vol 98 (9) ◽  
pp. 1476-1481 ◽  
Author(s):  
Ji-Won Lee ◽  
Jeong Ae Park ◽  
Se-Hee Kim ◽  
Ji Hae Seo ◽  
Kyung-Joon Lim ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1Α ◽  
Kinase C ◽  
The Stability

Protein kinase C isotypes in human erythroleukemia cell proliferation and differentiation

1992 ◽  
Vol 101 (3) ◽  
pp. 671-679
Author(s):  
B.A. Hocevar ◽  
D.M. Morrow ◽  
M.L. Tykocinski ◽  
A.P. Fields
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cellular Proliferation ◽  
Biological Effects ◽  
Growth Arrest ◽  
Tumor Promoter ◽  
Induced Differentiation ◽  
Megakaryocytic Differentiation ◽  
Kinase C ◽  
Dose Dependent

The human erythroleukemia (K562) cell line is induced to differentiate into megakaryocytic cells by treatment with the tumor promoter phorbol myristate acetate (PMA). PMA-induced differentiation is characterized by (1) almost complete cessation of cellular proliferation, (2) expression of the megakaryocytic cell surface marker glycoprotein IIb/IIIa (gpIIIa), (3) increased secretion of granulocyte/macrophage-colony stimulating factor (GM-CSF) and (4) increased secretion of interleukin-6 (IL-6). PMA-induced differentiation is dose-dependent with maximal activity seen at 10 nM PMA. In contrast, bryostatin (bryo), a structurally distinct protein kinase C (PKC) activator, fails to induce megakaryocytic differentiation or growth arrest at the concentrations tested (0.01-100 nM). Rather, bryo inhibits PMA-induced growth arrest and megakaryocytic differentiation in a dose-dependent fashion (full inhibition at 100 nM). The divergent biological effects of PMA and bryo correspond to the differential activation and translocation of PKC isotypes in K562 cells. PKC isotype analysis demonstrates that undifferentiated cells express both alpha and beta II PKC but no detectable beta I, gamma or epsilon PKC. Treatment of cells with either PMA or bryo leads to rapid translocation of both alpha and beta II PKC from the cytosol to the non-nuclear particulate fraction. However, bryo also induces selective translocation of beta II PKC to the nuclear membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of glucocorticoid on prostaglandin F2α-induced prostaglandin E2 synthesis in osteoblast-like cells: inhibition of phosphoinositide hydrolysis by phospholipase C as well as phospholipase A2

1994 ◽  
Vol 131 (5) ◽  
pp. 510-515 ◽  
Author(s):  
Osamu Kozawa ◽  
Haruhiko Tokuda ◽  
Atsushi Suzuki ◽  
Jun Kotoyori ◽  
Yoshiaki Ito ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase A2 ◽  
Phospholipase C ◽  
Phospholipase A ◽  
Phosphoinositide Hydrolysis ◽  
Prostaglandin E ◽  
Dependent Manner ◽  
Kinase C ◽  
Dose Dependent

Kozawa O, Tokuda H, Suzuki A, Kotoyori J, Ito Y, Oiso Y. Effect of glucocorticoid on prostaglandin F2α-induced prostaglandin E2 synthesis in osteoblast-like cells: inhibition of phosphoinositide hydrolysis by phospholipase C as well as phospholipase A2. Eur J Endocrinol 1994;131:510–15. ISSN 0804–4643 It is well known that osteoporosis is a common complication of patients with glucocorticoid excess. We showed previously that prostaglandin (PG) F2α stimulates the synthesis of PGE2, a potent bone resorbing agent, and that the activation of protein kinase C amplifies the PGF2α-induced PGE2 synthesis through the potentiation of phospholipase A2 activity in osteoblast-like MC3T3-E1 cells. In the present study, we examined the effect of dexamethasone on PGE2 synthesis induced by PGF2α in MC3T3-E1 cells. The pretreatment with dexamethasone significantly inhibited the PGE2 synthesis in a dose-dependent manner in the range between 0.1 and 10 nmol/l in these cells. This effect of dexamethasone was dependent on the time of pretreatment up to 8 h. Dexamethasone also inhibited PGE2 synthesis induced by melittin, known as a phospholipase A2 activator. Furthermore, dexamethasone significantly inhibited the enhancement of PGF2α- or melittin-induced PGE2 synthesis by 12-O-tetradecanoylphorbol-13-acetate, known as a protein kinase C activator. In addition, dexamethasone significantly inhibited PGF2α-induced formation of inositol phosphates in a dose-dependent manner between 0.1 and 10 nmol/l in MC3T3-E1 cells. These results strongly suggest that glucocorticoid inhibits PGF2α-induced PGE2 synthesis through the inhibition of phosphoinositide hydrolysis by phospholipase C as well as phospholipase A2 in osteoblast-like cells. Osamu Kozawa, Department of Biochemistry, Institute for Developmental Research, Aichi Prefectural Colony, Kasugai, Aichi 480-03, Japan

Potential mediation of somatostatin secretion from canine fundic D-cells by protein kinase c

1987 ◽  
Vol 253 (1) ◽  
pp. G62-G67
Author(s):  
T. Chiba ◽  
K. Sugano ◽  
J. Park ◽  
T. Yamada
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phosphatidic Acid ◽  
Phosphatidyl Inositol ◽  
Membrane Phospholipids ◽  
Kinase C ◽  
Dose Dependent Fashion ◽  
D Cells ◽  
Two Parameters ◽  
Dose Dependent

We examined the possible importance of protein kinase c-dependent mechanisms in mediating the stimulatory effects of gastrin and cholecystokinin (CCK) on the release of somatostatin-like immunoreactivity (SLI) from isolated canine fundic D-cells. Diacylglycerides, presumably the products of phosphoinositide breakdown that activate protein kinasec, and phospholipase C, which catalyzes the production of endogenous diacylglycerides from membrane phospholipids, both stimulated SLI secretion in a dose-dependent fashion. Both classes of agents potentiated the actions of adenosine 3',5'-cyclic monophosphate-dependent agonists but not those of gastrin and CCK. The stimulatory effects of gastrin and CCK correlated with their abilities to enhance the incorporation of 32P into membrane phosphatidyl inositol and phosphatidic acid and promote the release of [3H]inositol trisphosphate from prelabeled D-cells, two parameters of phosphoinositide turnover. These data suggest that protein kinase c may serve to transduce the signals activated by gastrin and CCK in D-cells.

PMA and staurosporine affect expression of the PCK gene in LLC-PK1-F+cells

1998 ◽  
Vol 275 (3) ◽  
pp. F361-F369 ◽  
Author(s):  
Wenlin Liu ◽  
Elisabeth Feifel ◽  
Thomas Holcomb ◽  
Xiangdong Liu ◽  
Nikolaus Spitaler ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Half Life ◽  
Rapid Decrease ◽  
Prolonged Treatment ◽  
Camp Response Element ◽  
Kinase C ◽  
F Cells ◽  
Chloramphenicol Acetyltransferase Gene ◽  
The Stability

The addition of phorbol 12-myristate 13-acetate (PMA) to renal LLC-PK1-F+cells caused a rapid decrease in the level of phospho enolpyruvate carboxykinase (PCK) mRNA and reversed the stimulatory effects of exposure to acidic medium (pH 6.9, 10 mM [Formula: see text]) or cAMP. In contrast, prolonged treatment with PMA increased the levels of PCK mRNA. The two effects correlated with the membrane translocation and downregulation of the α-isozyme of protein kinase C and were blocked by pretreatment with specific inhibitors of protein kinase C. The rapid decrease in PCK mRNA caused by PMA occurred with a half-life ( t ½ = 1 h) that is significantly faster than that measured during recovery from acid medium or following inhibition of transcription ( t ½ = 4 h). The effect of PMA was reversed by staurosporine, which apparently acts by inhibiting a signaling pathway other than protein kinase C. Staurosporine had no effect on the half-life of the PCK mRNA, but it stimulated the activity of a chloramphenicol acetyltransferase gene that was driven by the initial 490 base pairs of the PCK promoter and transiently transfected into LLC-PK1-F+cells. This effect was additive to that of cAMP, and neither stimulation was reversed by PMA. The stimulatory effect of staurosporine was mapped to the cAMP response element (CRE-1) and P3(II) element of the PCK promoter. The data indicate that, in LLC-PK1-F+cells, activation of protein kinase C decreases the stability of the PCK mRNA, whereas transcription of the PCK gene may be suppressed by a kinase that is inhibited by staurosporine.

Mechanisms of PTH-induced rise in cytosolic calcium in adult rat hepatocytes

1994 ◽  
Vol 267 (5) ◽  
pp. G754-G763 ◽  
Author(s):  
M. Klin ◽  
M. Smogorzewski ◽  
H. Khilnani ◽  
M. Michnowska ◽  
S. G. Massry
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
G Protein ◽  
Cytosolic Calcium ◽  
Amino Terminal ◽  
Kinase C ◽  
Dose Dependent ◽  
Kinase A ◽  
Stimulation Of

Available data indicate that the liver is a target organ for parathyroid hormone (PTH) and that this effect is most likely mediated by PTH-induced calcium entry into hepatocytes. The present study examined the effects of both PTH-(1-84) and its amino-terminal fragment [PTH-(1-34)] on cytosolic calcium concentration ([Ca2+]i) of hepatocytes and explored the cellular pathways that mediate this potential action of PTH. Both moieties of PTH produced a dose-dependent rise in [Ca2+]i, but the effect of PTH-(1-84) was greater (P < 0.01) than an equimolar amount of PTH-(1-34). This effect required calcium in the medium and was totally [PTH-(1-34)] or partially [PTH-(1-84)] blocked by PTH antagonist ([Nle8,18,Tyr34]bPTH-(7-34)-NH2] and by verapamil or nifedipine. Sodium or chloride channel blockers did not modify this effect. 12-O-tetradecanoylphorbol 13-acetate (TPA), an activator of protein kinase C, dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP), and G protein activator also produced a dose-dependent rise in [Ca2+]i. Staurosporine abolished the effect of TPA, and both staurosporine and calphostin C partially inhibited the effect of PTH. Staurosporine and verapamil together produced greater inhibition of PTH action than each alone. Rp-cAMP, a competitive inhibitor of cAMP binding to the R subunit of protein kinase A, and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89), a protein kinase A inhibitor, blocked the effect of both DBcAMP and PTH, but the effect of these agents was greater (P < 0.01) on DBcAMP action. G protein inhibitor and pertussis toxin partially blocked the action of PTH. The data indicate that 1) PTH increases [Ca2+]i of hepatocytes; 2) this action of the hormone is receptor mediated; 3) the predominant pathway for this PTH action is the stimulation of a G protein-adenylate cyclase-cAMP system, which then leads to stimulation of a calcium transport system inhibitable by verapamil or nifedipine or activation of L-type calcium channels; 4) activation of protein kinase C is also involved; and 5) the PTH-induced rise in [Ca2+]i is due, in major parts, to movement of extracellular calcium into the cell.

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