Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Translation initiation factor eIF-4E, which binds to the 5' cap structure of eukaryotic mRNAs, is believed to play an important role in the control of cell growth. Consistent with this, overexpression of eIF-4E in fibroblasts results in their malignant transformation. The activity of eIF-4E is thought to be regulated by phosphorylation on a single serine residue (Ser-53). Treatment of rat pheochromocytoma (PC12) cells with nerve growth factor (NGF) strongly curtails their growth and causes their differentiation into cells that resemble sympathetic neurons. The present study shows that eIF-4E is rapidly phosphorylated in PC12 cells upon NGF treatment, resulting in a significant increase in the steady-state levels of the phosphorylated protein. In contrast, epidermal growth factor, a factor which elicits a weak mitogenic response in PC12 cells, did not significantly enhance eIF-4E phosphorylation. We also show that although the mitogen and tumor promoter, phorbol 12-myristate-13-acetate, is able to induce phosphorylation of eIF-4E in PC12 cells, the NGF-mediated increase is primarily a protein kinase C-independent response. The NGF-induced enhancement of eIF-4E phosphorylation is abrogated in PC12 cells expressing a dominant inhibitory ras mutant (Ser-17 replaced by Asn), indicating that eIF-4E phosphorylation is dependent on a ras signalling pathway. As phosphorylation of eIF-4E effects translation initiation, these results suggest that NGF-mediated and ras-dependent eIF-4E phosphorylation may play a role in switching the pattern of gene expression during the differentiation of PC12 cells.
Mol Cell Biol 1992 Mar
PMID:Phosphorylation of translation initiation factor eIF-4E is induced in a ras-dependent manner during nerve growth factor-mediated PC12 cell differentiation. 154 5

The complete nucleotide sequence is presented for pUH24, the small plasmid of Synechococcus sp. PCC 7942. pUH24 consists of 7835bp and has a G + C content of 59%. The distribution of translation start and stop codons in the sequence allows 36 open reading frames that potentially encode polypeptides of 50 or more amino acids. We postulate that eight of these open reading frames are actual coding sequences. A region has been identified, by experiment, that contains two functions, designated pmaA and pmaB, involved in the segregational stability of the plasmid. The minimal region of pUH24 fully capable of supporting autonomous replication consists of a 3.6kb DNA fragment, which is almost entirely occupied by two overlapping genes most likely coding for essential replication proteins (repA and repB).
Mol Microbiol 1992 Mar
PMID:Identification of replication and stability functions in the complete nucleotide sequence of plasmid pUH24 from the cyanobacterium Synechococcus sp. PCC 7942. 155 63

The nucleotide sequence of an 813 bp Ssp I-Hinc II fragment containing the psaC gene from Anabaena sp. PCC 7120 is reported. The gene encodes a polypeptide of 81 amino acids, has a single transcript of size approximately 480 nucleotides and a single startpoint of transcription. It is flanked by a ribosome binding site on the 5' end and a potential transcription terminator on the 3' end. Comparison of the amino acid sequences of the psaC gene product from sixteen organisms shows that cyanobacteria group as a cluster distinct from monocotyledonous and dicotyledonous plants and that individual amino acids are diagnostic of each cluster.
Plant Mol Biol 1992 Feb
PMID:Nucleotide sequence and expression of the gene for the 9 kDa FA/FB component of photosystem I from the cyanobacterium Anabaena sp. PCC7120. 155 54

The reaction center core of photosystem II, a multiprotein membrane bound complex, is composed of a heterodimer of two proteins, D1 and D2. A random mutagenesis technique was used to isolate a photosystem II deficient mutant, CP6t16, of the unicellular cyanobacterium, Synechocystis sp. PCC 6803. Nucleotide sequence analysis showed that the primary lesion in CP6t16 is an ochre mutation introducing a translational stop codon in the psbE gene, encoding the alpha-subunit of cytochrome b559, an integral component of the PSII complex. Analysis of the protein composition of CP6t16 thylakoid membranes isolated in the presence of serine protease inhibitors revealed that, in the absence of cytochrome b559, the D2 protein is also absent. However, the D1 protein is stably incorporated in these membranes, suggesting that the synthesis and integration of D1 are independent of those of D2 and cytochrome b559.
Mol Microbiol 1992 Apr
PMID:The D1 protein of the photosystem II reaction-centre complex accumulates in the absence of D2: analysis of a mutant of the cyanobacterium Synechocystis sp. PCC 6803 lacking cytochrome b559. 160 69

We have cloned full-length DDC cDNAs from a human hepatoma cDNA library [DDC; dopa decarboxylase; aromatic-L-amino acid decarboxylase, EC 4.1.1.28]. The protein encoded by hepatoma cells is the same as that encoded by adrenal chromaffin derived pheochromocytoma cells, despite reported differences in biochemical properties. We have confirmed the location of the DDC gene to chromosome 7 using a new panel of somatic cell hybrids, and we have localized the gene to band p11 on chromosome 7 by fluorescent in situ hybridization. The human gene retains 65% amino acid identity with Drosophila DDC (Accession No. X04426) and considerable structural similarity with other enzymes (F.R. Jackson, 1990, J. Mol. Evol. 31:325-329, and references therein).
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PMID:Human dopa decarboxylase: localization to human chromosome 7p11 and characterization of hepatic cDNAs. 161 8

The protein kinase C (PKC) inhibitor staurosporine, a member of the K252a family of fungal alkaloids that are known as protein kinase inhibitors, induces neurite outgrowth in pheochromocytoma PC12 cells. The progressive staurosporine-induced neurotropic effect (EC50 = 50 nM) has the following characteristics: it is evident after 4 hr of incubation, requires the continuous presence of staurosporine, occurs at 37 degrees but not at 4 degrees, and is not blocked by K252a derivatives. Scanning electron micrographs showed long neurites, ruffling, and dense networks in nerve growth factor (NGF)-treated cells and short neurites, flattening, and smooth cell surface in staurosporine-treated cells. [3H]Staurosporine binding, which was time, temperature, and dose dependent, saturated at 5-10 nM. Other kinase inhibitors were poor competitors. The [3H]staurosporine bound over 20 hr at 37 degrees was poorly dissociated by acetic acid wash or unlabeled staurosporine. These results suggest an uptake process occurring at 37 degrees that is required for the neurotropic effect of staurosporine. NGF did not interfere with staurosporine binding, and staurosporine did not affect NGF receptor binding. At neurotropic concentrations of staurosporine, PKC in PC12 cells was completely inhibited. When PKC activity was down-regulated by prolonged exposure to phorbol myristate acetate, PC12 cells responded to staurosporine with neurite outgrowth similar to that of untreated cells. Although the target and mechanism of the neurotropic effects of staurosporine remain to be determined, the observed effects on PKC-deficient cells indicate that PKC may not be required for the neurotropic effect of this compound in PC12 cells. These results suggest that caution should be taken in the interpretation of staurosporine action in vivo, and they provide a pharmacological tool for the development of potential neurotropic drugs.
Mol Pharmacol 1992 Jul
PMID:Staurosporine-induced neurite outgrowth in PC12 cells is independent of protein kinase C inhibition. 163 52

The glucose-6-phosphate dehydrogenase (EC 1.1.1.49) gene (zwf) of the cyanobacterium Synechococcus PCC 7942 was cloned on a 2.8 kb Hind III fragment. Sequence analysis revealed an ORF of 1572 nucleotides encoding a polypeptide of 524 amino acids which exhibited 41% identity with the glucose-6-phosphate dehydrogenase of Escherichia coli.
Plant Mol Biol 1992 Aug
PMID:Cloning and sequence analysis of the glucose-6-phosphate dehydrogenase gene from the cyanobacterium Synechococcus PCC 7942. 164 89

The rat pheochromocytoma cell line PC12 can be induced by growth factors to undergo proliferation and neuronal differentiation. These cells also have excitable membranes that can be depolarized by neurotransmitters or elevated levels of extracellular KCl. Treatment of PC12 cells with growth factors or membrane-depolarizing agents rapidly activates the expression of specific genes whose products are thought to mediate the subsequent biological responses. One such gene, nur77, is a member of the steroid and thyroid hormone receptor gene superfamily. We have identified the Nur77 protein and shown that it is synthesized rapidly and transiently in PC12 cells following stimulation, has a short half-life of 30 to 40 min, and is located in both the nucleus and the cytoplasm. Nur77 is posttranslationally modified, primarily by phosphorylation on serine residues. Phosphopeptide analysis reveals that Nur77 is modified differently upon membrane depolarization than after treatment with growth factors. We hypothesize that the activity of Nur77 is regulated by both differential gene expression and posttranslational modification and that these modes of regulation contribute to distinct downstream responses specific to membrane depolarization and growth factor treatment.
Mol Cell Biol 1991 Jun
PMID:Nur77 is differentially modified in PC12 cells upon membrane depolarization and growth factor treatment. 164 47

Analysis of cyclic nucleotide phosphodiesterase (PDE) activity in cellular fractions from cultured rat pheochromocytoma (PC12) cells has shown that the predominant hydrolytic activity in both cytosolic and particulate compartments is characteristic of a PDE II, the cGMP-activatable family of PDE isozymes. Cytosolic PDE activity was purified to a high degree utilizing DE-52 anion exchange and cGMP-Sepharose affinity chromatographies. The physicochemical properties of PC12 PDE II were similar to those of PDE II isolated from particulate or soluble fractions of other tissues, including subunit molecular weight of approximately 102,000, activation of cAMP hydrolysis by cGMP, and positive cooperative kinetic behavior for cAMP and cGMP hydrolysis. The potential role of PDE II in regulating cAMP metabolism in intact PC12 cells was studied using an [3H]adenine prelabeling technique. Stimulation of PC12 cell adenosine receptors resulted in a 5-8-fold increase in cAMP accumulation. Removal of the adenosine stimulus by the addition of exogenous adenosine deaminase resulted in a rapid decay of cAMP to prestimulated basal levels within 2 min. Treatment of PC12 cells with atrial natriuretic factor or sodium nitroprusside caused 1) increased intracellular cGMP levels, 2) attenuation of adenosine-stimulated cAMP accumulation, and 3) increased rates of cAMP decay after removal of the adenosine stimulus. Treatment of PC12 cells with HL-725 (a potent inhibitor of isolated PDE II activity in vitro) caused 1) increased basal cAMP accumulation, 2) potentiation of adenosine-stimulated cAMP accumulation, and 3) retardation of the rate of cAMP decay after removal of the adenosine stimulus. HL-725 blocked both the attenuation of cAMP accumulation and the accelerated rate of cAMP decay observed with the cGMP-elevating agents. These results suggest that, in PC12 cells, drugs or hormones that inhibit PDE II or increase intracellular cGMP levels to activate PDE II can modulate cAMP metabolism by altering the catalytic status of the enzyme.
Mol Pharmacol 1991 Jun
PMID:Phosphodiesterase II, the cGMP-activatable cyclic nucleotide phosphodiesterase, regulates cyclic AMP metabolism in PC12 cells. 164 46

We describe the characterization of two insertion elements, IS701 and IS702, isolated from Calothrix species PCC 7601. These insertion elements were cloned from spontaneous pigmentation mutants. Both show the characteristics of typical bacterial insertion sequences, i.e. they present long terminal inverted repeats and they duplicate target DNA upon insertion. These elements share no homology with the only other cyanobacterial insertion sequence described so far, IS891. At least 15 copies of IS701 and 9 copies of IS702 were detected by hybridization experiments in the Calothrix 7601 genome. Their occurrence in several cyanobacterial strains is also reported.
Mol Microbiol 1991 Sep
PMID:Characterization of two insertion sequences, IS701 and IS702, from the cyanobacterium Calothrix species PCC 7601. 166 61


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