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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pituitary peptide hormone prolactin exerts a profound effect on various physiological processes involving both cellular proliferation and differentiation. The rat Nb2 T lymphoma cell line has been used as a model system for studying prolactin regulation of cell proliferation. Several genes associated with cell growth (c-myc, ornithine decarboxylase (ODC), heat shock protein 70 (hsp 70)-homologue, and beta-actin) are induced rapidly within 4 h after prolactin addition. Nuclear run-on transcription assays indicate that prolactin induction of these growth-related genes occurs primarily at the transcriptional level. According to the different kinetics of transcriptional response to prolactin, these growth-related genes can be divided into immediate-early (actin, c-myc), early (ODC) and mid-G1 (hsp 70-homologue) genes. Thus, prolactin may regulate Nb2 T cell-proliferative responses by modulating the transcriptional induction of various growth-related genes. These studies also represent a first report of a transcriptional cascade set off in rapid response to prolactin in cultured T cells.
Mol Cell Endocrinol 1990 Jan 02
PMID:Prolactin stimulates transcription of growth-related genes in Nb2 T lymphoma cells. 240 73

We have studied a panel of 10 genes and cDNA sequences that are expressed in a cell cycle-dependent manner in different types of cells from different species and that are inducible by different mitogens. These include five sequences (c-myc, 4F1, 2F1, 2A9, and KC-1) that are preferentially expressed in the early part of the G1 phase, three genes (ornithine decarboxylase, p53, and c-rasHa) preferentially expressed in middle or late G1, and two genes (thymidine kinase and histone H3) preferentially expressed in the S phase of the cell cycle. We have studied the expression of these genes in nonpermissive (tsAF8) and semipermissive (Swiss 3T3) cells infected with adenovirus type 2. Under the conditions of these experiments, adenovirus type 2 infection stimulates cellular DNA synthesis in both tsAF8 and 3T3 cells. However, four of the five early G1 genes (c-myc, 4F1, KC-1, and 2A9) and one of the late G1 genes (c-ras) are not induced by adenovirus infection, although they are strongly induced by serum. The other sequences (2F1, ornithine decarboxylase, p53, thymidine kinase, and histone H3) are activated by both adenovirus and serum. We conclude that the cell cycle-dependent genes activated by adenovirus 2 are a subset of the cell cycle-dependent genes activated by serum. The data suggest that the mechanisms by which serum and adenovirus induce cellular DNA synthesis are not identical.
Mol Cell Biol 1985 Nov
PMID:Adenovirus type 2 activates cell cycle-dependent genes that are a subset of those activated by serum. 242 24

The activity of ornithine decarboxylase (ODC) is negatively regulated by intracellular polyamines, which thereby mediate a form of feedback inhibition of the initial enzyme in the pathway of their synthesis. This phenomenon has been believed to result, at least in part, from translational regulation. To investigate this further, we performed four series of experiments. First, we found that a chimeric protein encoded by an mRNA containing the ODC 5' leader sequence did not exhibit polyamine-dependent regulation. Second, we showed that transcripts containing the protein-coding sequence of ODC, but no other ODC-derived sequence information, exhibited regulation. Third, we found that the association of ODC mRNA with ribosomes was not altered when intracellular polyamine levels were modulated under conditions previously deemed to cause translational regulation. Last, we carried out experiments to measure the incorporation of [35S]methionine into ODC in polyamine-starved and polyamine-replete cells. Differential incorporation diminished progressively as pulse-label times were shortened; at the shortest labeling time used (4 min), the difference in favor of ODC in polyamine-starved cells was less than twofold. These findings suggest that it is necessary to reevaluate the question of whether polyamines cause alterations of translation of ODC mRNA.
Mol Cell Biol 1989 Dec
PMID:Polyamine-mediated regulation of mouse ornithine decarboxylase is posttranslational. 251 35

The metabolism of L-arginine and L-ornithine was examined in tumoral islet cells of the RINm5F line and compared to the situation previously characterized in normal rat islets. The maximal velocity of arginase in cell homogenates, as well as either the production of 14C-urea or the steady-state content of 14C-labelled ornithine in intact cells exposed to L-[U-14C]arginine were about one order of magnitude lower in tumoral than normal islet cells. The activity of ornithine-glutamate transaminase was similar in both cell types, and this coincided with a comparable rate of 14C-labelled L-glutamate generation by intact cells exposed to L-[1-14C]ornithine. Despite a comparable cell content in 14C-labelled ornithine of normal and tumoral cells exposed to exogenous ornithine, the rate of di- and polyamine generation was about one order of magnitude higher in tumoral than normal islet cells, this coinciding with a much higher activity of ornithine decarboxylase in RINm5F cell than islet homogenates.
Mol Cell Endocrinol 1989 Nov
PMID:Stimulus-secretion coupling of arginine-induced insulin release: metabolism of L-arginine and L-ornithine in tumoral islet cells. 255 31

A group of Chinese hamster ovary (CHO) cell mutants deficient in ornithine decarboxylase (ODC) activity are described and compared to the prototype mutant reported previously (21). Although all mutants belong to the same complementation group, they can be divided into two classes: those with some residual enzyme activity and those with no activity. All mutants are putrescine auxotrophs, but they differ in their ability to utilize the enzyme's substrate, ornithine, a property which correlates with the amount of residual enzyme activity. The mutants also differ in their frequency of reversion to prototrophy. The leaky mutants revert at a high rate by overproducing a partially defective enzyme by a gene amplification mechanism similar to that leading to the ornithine analog-resistant mutants which have elevated enzyme levels. Spontaneous reversion in the null mutants is rare. However, one null mutant, which was induced with ethyl methane sulfonate and which makes ODC mRNA but no active enzyme, is nevertheless revertible with 5-azacytidine. We conclude that CHO cells are at least diploid at the ODC locus, but that only one allele is active. Further studies suggest the possibility that ethyl methane sulfonate is not just a classical mutagen but may also induce gene inactivations that are revertible by 5-azacytidine.
Somat Cell Mol Genet 1985 Jan
PMID:Chinese hamster cells deficient in ornithine decarboxylase activity: reversion by gene amplification and by azacytidine treatment. 257 46

12-O-tetradecanoylphorbol-13-acetate (TPA) induced ornithine decarboxylase (ODC) and suppressed 125I-epidermal growth factor (EGF) binding in primary cultured mouse epidermal cells. TPA (30 nM)-caused ODC induction was almost completely blocked by 30 microM H-7 [1-(5-isoquinolinylsulfonyl)-2-methylpiperazine], a well known protein kinase C inhibitor, but the same concentration of H-7 failed to restore the 125I-EGF binding suppressed by TPA (10 nM). On the other hand, sphingosine, another protein kinase C inhibitor, blocked not only TPA-caused ODC induction but also TPA-caused suppression of 125I-EGF binding. Concentration-response curves of sphingosine for these two TPA-caused cellular responses were almost identical. 1,2-Diacylglycerols such as 1,2-dioctanoylglycerol (30-300 microM) and 1-oleoyl-2-acetylglycerol (OAG) (30-300 microM) mimicked TPA actions. Similar to the case of TPA, suppression of 125I-EGF binding by OAG was barely inhibited by H-7, whereas sphingosine was more effective in inhibiting the OAG-caused suppression of 125I-EGF binding than was H-7. In TPA (50 nM)-pretreated epidermal cells, TPA (10 nM) failed to suppress 125I-EGF binding. H-7 (30 microM) did not affect TPA (30 nM)-caused translocation of protein kinase C. These results clearly demonstrate the differential inhibition by H-7 of the TPA-caused cellular responses and indicate that TPA-caused suppression of 125I-EGF binding to epidermal cells is mediated through protein kinase C function, which is barely inhibited by H-7.
Mol Pharmacol 1989 Dec
PMID:H-7, a protein kinase C inhibitor, inhibits phorbol ester-caused ornithine decarboxylase induction but fails to inhibit phorbol ester-caused suppression of epidermal growth factor binding in primary cultured mouse epidermal cells. 260 87

Casein kinase II from a virally-transformed macrophage cell line (RAW264) was purified by a sequential DEAE, Procion Red, phosvitin-Sepharose and heparin-Sepharose chromatography. With [tau-32P]GTP as a phosphate donor and casein as a substrate, the kinase was stimulated by polyamines and inhibited by heparin. The purified kinase had a specific activity of 1137 nmol/min/mg protein and exhibited three major protein bands of 40 K, 35 K, and 25 K. Under non-denaturing conditions in 50 mM Tris-50 mM NaCl the enzyme was eluted as a single peak with molecular weight of 110 K. Incubation of kinase in the presence of [tau-32P]GTP and Mg2+ resulted in phosphorylation of the 25 K protein band of the enzyme. In the presence of [tau-32P]GTP and Mg2+ the kinase was able to phosphorylate 55 K protein band in purified ornithine decarboxylase preparation from RAW264 cells and the rat-type II regulatory subunit of the cyclic AMP-dependent protein kinase.
Cell Mol Biol 1989
PMID:Characterization of casein kinase II from a virally transformed macrophage-like cell line, RAW264. 262 1

1. Glucocorticoid hormones affect several functions of the spinal cord, such as synaptic transmission, biogenic amine content, lipid metabolism, and the activity of some enzymes (ornithine decarboxylase, glycerolphosphate dehydrogenase), indicating that this tissue is a target of adrenal hormones. 2. Corticosterone, the main glucocorticoid of the rat, is detected at all regional levels of the spinal cord, and cold stress increases this steroid, predominantly in the cervical regions. 3. Intracellular glucocorticoid receptors have been found in the spinal cord, with higher concentrations in the cervical and lumbar enlargements. Prima facie, these receptors presented biochemical, stereospecifical, and physicochemical properties similar to those of receptors found in other regions of the nervous system. The prevalent form in the spinal cord is the type II receptor, although type I is also present in small amounts. 4. The type II glucocorticoid receptor of the spinal cord shows an affinity lower (Kd 3.5 nM) than that of the hippocampal type II site (Kd 0.7 nM) when incubated with [3H]dexamethasone. This condition may impair the nuclear translocation of the spinal cord receptor. 5. Another peculiar property of spinal cord type II site is a greater affinity for DNA-cellulose binding than the hippocampal receptor during heat-induced transformation. Also, the spinal cord receptor shows resistance to the action of RNAse A, an enzyme which increases DNA-cellulose binding of the hippocampal receptor, indicating that both receptors may be structurally different. 6. Therefore, it is possible that a different subclass of type II, or "classical glucocorticoid receptor," is present in the spinal cord. This possibility makes the cord a useful system for studying diversity of glucocorticoid receptors of the nervous system, especially the relationship between receptor structure and function.
Cell Mol Neurobiol 1989 Jun
PMID:Adrenocorticoid action in the spinal cord: some unique molecular properties of glucocorticoid receptors. 266 68

Northern blot analysis with specific probes indicates that, in the liver of normothermic rats under the carcinogenic regimen of Solt and Farber (Nature 263:701, 1976), diethylnitrosamine (DEN), 2-acetylaminofluorene (AAF), and partial hepatectomy (PH), either alone or in combination, do not induce the expression of the heat-shock protein 70 (hsp70) gene family. On the contrary, the inducibility of hsp70 mRNAs in the liver of heat-shocked animals is maintained throughout the treatment, as it is in nodules that are found in the liver 2 weeks posttreatment. The steady-state level of the constitutive hsp70-related cognate protein (hsc73) mRNA, which is known to be particularly high in fast-growing cells, increases above the normal level only during liver regeneration, stays at a high level up to 8 days after hepatectomy, independently of any associated exposure to carcinogenic chemicals, and is practically unchanged in the nodules. Ornithine decarboxylase mRNA increases only in livers of normothermic rats at 16 h of regeneration. The expression of the c-Ha-ras oncogene increases slightly, but steadily, during the carcinogenic treatment and persists at a high level when other changes have subsided.
Mol Carcinog 1989
PMID:Expression pattern of the genes for different members of the heat-shock protein 70 family, ornithine decarboxylase, and c-Ha-ras during the early stages of hepatocarcinogenesis. 269 Aug 52

Recently, the protein kinase C (PKC) activator 12-O-tetradecanoylphorbol 13-acetate (TPA) was found to have prolactin (PRL)-like actions on specific metabolic processes in mouse mammary gland explants. Since TPA is known to stimulate PKC, these observations suggest that PKC may have a role in the PRL stimulation of lactogenic processes. The present studies provide further evidence for this by demonstrating a transient, time-dependent translocation of PKC to the particulate fraction in response to PRL. Particulate-associated PKC reached a maximum between 15-30 min and returned to control values within 1-2 h after PRL treatment. PRL treatment for 16 h also induced a down-regulation of total cellular PKC. Inhibition of PKC function, either by a 30 h pretreatment with TPA (PKC down-regulation) or 2 h with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7), resulted in an attenuation of PRL-stimulated effects on ornithine decarboxylase activity and synthesis of RNA, caseins, and lipids.
Mol Cell Endocrinol 1989 May
PMID:Role of protein kinase C in the prolactin-induced responses in mouse mammary gland explants. 275 24


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