Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031511 (pheochromocytoma)
 14,622 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

All the nitrogen signals from the amino acid side chains and 80 of the total of 98 backbone nitrogen signals of the oxidized form of the 2Fe.2S* ferredoxin from Anabaena sp. strain PCC 7120 were assigned by means of a series of heteronuclear two-dimensional experiments [Oh, B.-H. Mooberry, E. S., & Markley, J. L. (1990) Biochemistry (second paper of three in this issue )]. Two additional nitrogen signals were observed in the one-dimensional 15N NMR spectrum and classified as backbone amide resonances from residues whose proton resonances experience paramagnetic broadening. The one-dimensional 15N NMR spectrum shows nine resonances that are hyperfine shifted and broadened. From this inventory of diamagnetic nitrogen signals and the available X-ray coordinates of a related ferredoxin [Tsukihara, T., Fukuyama, K., Nakamura, M., Katsube, Y., Tanaka, N., Kakudo, M., Wada, K., Hase, T., & Matsubara, H. (1981) J. Biochem. 90, 1763-1773], the resolved hyperfine-shifted 15N peaks were attributed to backbone amide nitrogens of the nine amino acids that share electrons with the 2Fe.2S* center or to backbone amide nitrogens of two other amino acids that are close to the 2Fe.2S* center. The seven 15N signals that are missing and unaccounted for probably are buried under the envelope of amide signals. 1H NMR signals from all the amide protons directly bonded to the seven missing and nine hyperfine-shifted nitrogens were too broad to be resolved in conventional 2D NMR spectra.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Multinuclear magnetic resonance studies of the 2Fe.2S* ferredoxin from Anabaena species strain PCC 7120. 3. Detection and characterization of hyperfine-shifted nitrogen-15 and hydrogen-1 resonances of the oxidized form. 235 73

Methylation by Ava methylases in Escherichia coli increases the efficiency to transfer of Tn5 in pBR322bla:: Tn5 from E. coli to Anabaena sp. strain PCC 7120 by conjugation. Following conjugation, Tn5 but not pBR322 sequences were found at many different positions in the Anabaena chromosome. This procedure was used to mutagenize, tag, and clone a previously unrecognized gene required for nitrogen fixation in this Anabaena sp.
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PMID:Tn5 mutagenesis of Anabaena sp. strain PCC 7120: isolation of a new mutant unable to grow without combined nitrogen. 255 92

A second nitrogen fixation (nif) operon in the cyanobacterium (blue-green alga) Anabaena (Nostoc) sp. strain PCC 7120 has been identified and sequenced. It is located just upstream of the nifHDK operon and consists of four genes in the order nifB, fdxN, nifS, and nifU. The three nif genes were identified on the basis of their similarity with the corresponding genes from other diazotrophs. The fourth gene, fdxN, codes for a bacterial type ferredoxin (Mulligan, M. E., Buikema, W. J., and Haselkorn, R. (1988) J. Bacteriol. 167, 4406-4410). The four genes are probably transcribed as a single operon, but are expressed at a lower level than the nifHDK operon, and only after a developmentally induced DNA rearrangement occurs that excises a 55-kilobase pair element from within the fdxN gene (Golden, J. W., Mulligan, M. E., and Haselkorn, R. (1987) Nature 327, 526-529; Golden, J. W., Carrasco, C. D., Mulligan, M. E., Schneider, G. J., and Haselkorn, R. (1988) J. Bacteriol. 170, 5034-5041). The promoter for the nifB operon was located by primer extension. Comparison of the nifB 5'-flanking sequence with the nifH 5'-flanking sequence did not reveal any consensus base pairs that would define a nif promoter for Anabaena. The operon contains two instances of 7-base pair directly repeated sequences: seven copies of the repeated sequence are found between the nifB and fdxN genes and six copies are found between the nifS and nifU genes. The function of these repeats is unknown.
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PMID:Nitrogen fixation (nif) genes of the cyanobacterium Anabaena species strain PCC 7120. The nifB-fdxN-nifS-nifU operon. 255 33

The nucleotide sequence of a region located downstream of the nifB gene, both in the cyanobacterium Anabaena sp. strain PCC 7120 and in Rhizobium meliloti, has been determined. This region contains a gene (fdxN) whose predicted polypeptide product strongly resembles typical bacterial ferredoxins. Cyanobacteria have not previously been shown to contain bacterial-type ferredoxins. The presence of this gene suggests that nitrogen-fixing cyanobacteria have at least four distinct ferredoxins.
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PMID:Bacterial-type ferredoxin genes in the nitrogen fixation regions of the cyanobacterium Anabaena sp. strain PCC 7120 and Rhizobium meliloti. 284 20

The filamentous cyanobacterium Anabaena sp. strain PCC 7120 produces terminally differentiated heterocysts in response to a lack of combined nitrogen. Heterocysts are found approximately every 10th cell along the filament and are morphologically and biochemically specialized for nitrogen fixation. At least two DNA rearrangements occur during heterocyst differentiation in Anabaena sp. strain PCC 7120, both the result of developmentally regulated site-specific recombination. The first is an 11-kilobase-pair (kb) deletion from within the 3' end of the nifD gene. The second rearrangement occurs near the nifS gene but has not been completely characterized. The DNA sequences found at the recombination sites for each of the two rearrangements show no similarity to each other. To determine the topology of the rearrangement near the nifS gene, cosmid libraries of vegetative-cell genomic DNA were constructed and used to clone the region of the chromosome involved in the rearrangement. Cosmid clones which spanned the DNA separating the two recombination sites that define the ends of the element were obtained. The restriction map of this region of the chromosome showed that the rearrangement was the deletion of a 55-kb DNA element from the heterocyst chromosome. The excised DNA was neither degraded nor amplified, and its function, if any, is unknown. The 55-kb element was not detectably transcribed in either vegetative cells or heterocysts. The deletion resulted in placement of the rbcLS operon about 10 kb from the nifS gene on the chromosome. Although the nifD 11-kb and nifS 55-kb rearrangements both occurred under normal aerobic heterocyst-inducing conditions, only the 55-kb excision occurred in argon-bubbled cultures, indicating that the two DNA rearrangements can be regulated differently.
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PMID:Deletion of a 55-kilobase-pair DNA element from the chromosome during heterocyst differentiation of Anabaena sp. strain PCC 7120. 314 75

PC12 pheochromocytoma cells take up 3,4-dihydroxyphenylethylamine (dopamine) and norepinephrine by a Na+-dependent, cocaine-sensitive system. The kinetics suggest that the same transporter functions for both substrates. Xylamine, a nitrogen mustard that blocks catecholamine uptake into neurons, irreversibly inhibited norepinephrine uptake into PC12 (IC50 = 15 microM). Pretreatment with 10 microM xylamine did not inhibit norepinephrine transport if 10 microM cocaine or 100 microM norepinephrine was also present during the pretreatment period or if Na+ was absent. These results indicate that xylamine must interact with the norepinephrine transporter to inhibit norepinephrine uptake. PC12 accumulated [3H]xylamine; this uptake had Na+-dependent and Na+-independent components. The Na+-dependent uptake was saturable (Km = 13 microM), and it was inhibited by cocaine (IC50 = 0.6 microM), desipramine (IC50 less than 1 nM), and norepinephrine (IC50 = 1 microM). Several proteins became prominently labeled when intact PC12 cells were incubated with [3H]xylamine; these proteins were enriched in a plasma membrane fraction and have molecular weights of 17,000, 24,000, 31,000, 33,000, 41,000, 42,000, 52,000, and 80,000. Other proteins were labeled less prominently. The labeling of all proteins was markedly decreased when the incubation with [3H]xylamine occurred in the presence of cocaine, desipramine, gramicidin D, or in a Na+-free buffer. These results indicate that xylamine must be transported into the cells for covalent binding to proteins to occur. [3H]Xylamine labeled essentially the same proteins when incubated with cell homogenates, but competition experiments with bretylium, desipramine, and cocaine failed to reveal which of the [3H]xylamine-labeled proteins is associated with the norepinephrine transporter.
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PMID:Characterization of xylamine binding to proteins of PC12 pheochromocytoma cells. 374 2

A novel post-translationally modified residue, gamma-N-methylasparagine, was detected in the beta subunit of Anabaena variabilis allophycocyanin. Structure determination was accomplished by isolating a decapeptide, AP-beta (63-72) shown to have the following structure: Ser-Asp-Ile-Thr-Arg-Pro-Gly-Gly- Asn[N-CH3]-homoserine lactone Fast atom bombardment-mass spectrometry established that the residue corresponding to position 71 in the protein (DeLange, R. J., Williams, L. C., and Glazer, A. N. (1981) J. Biol. Chem. 256, 9558-9566) contained 13 mass units more than expected for aspartic acid though aspartic acid was recovered after acid hydrolysis. The 1H NMR spectrum of AP-beta (63-72) revealed a strong methyl single at 2.71 ppm characteristic of the methyl derivative of an amide nitrogen. Confirmation of this bond arrangement was obtained by detection of a stoichiometric amount of methylamine in acid hydrolysates of the peptide. This is the first report of gamma-N-methylasparagine in a protein. Amino acid analysis of A. variabilis allophycocyanin subunits showed that the derivative at position 71 can account for the total methylamine released from the beta subunit, while hydrolysis of the alpha subunit released no methylamine. The beta subunits of the allophycocyanins from the cyanobacterium Synechococcus PCC 6301 and the red alga Porphyridium cruentum each released 1 eq of methylamine upon acid hydrolysis. No methylamine was released from the alpha subunits.
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PMID:Post-translational methylation of asparaginyl residues. Identification of beta-71 gamma-N-methylasparagine in allophycocyanin. 378 95

The purpose of these experiments was to determine the role of double-strand breaks in chromosome aberration formations. Quiescent normal human fibroblasts were treated with 3 microM nitrogen mustard and then allowed to repair their DNA damage for 24 h prior to cell fusion and induction of premature chromosome condensation. The extent of chromosome damage was determined in the G1 prematurely condensed chromosomes (G1 PCC). The presence of cytosine arabinoside and hydroxyurea during the repair period in order to accumulate single-strand DNA breaks resulted in an increase in the chromosome-break frequency. Treatment of these repair-inhibited cells with single-strand-specific neurospora endonuclease during fusion to change single-strand lesions into double-strand breaks resulted in a doubling of the aberration frequency. These results support the notion that double-strand breaks are important in chromosome-aberration formation.
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PMID:Induction of chromosome damage by Neurospora endonuclease in repair-inhibited quiescent normal human fibroblasts. 609 3

Probes carrying the Anabaena sp. strain PCC 7120 nitrogenase reductase (nifH) and nitrogenase (nifK and nifD) genes were hybridized to Southern blots of DNA from the unicellular, aerobic nitrogen-fixing cyanobacterium Gloeothece sp. strain PCC 6909 and from the filamentous cyanobacterium Calothrix sp. strain PCC 7601. These data suggest that the Gloeothece sp. nif structural proteins must be similar to those of other diazotrophs and that the ability for aerobic nitrogen fixation does not reside in the nif protein complex. We also found that the nif structural genes of Gloeothece sp. are clustered, whereas those of Calothrix sp. are arranged more like those of Anabaena sp.
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PMID:The structural nif genes of the cyanobacteria Gloeothece sp. and Calothrix sp. share homology with those of Anabaena sp., but the Gloeothece genes have a different arrangement. 630 21

Protein kinases play essential roles in the development of eukaryotic cells. These enzymes display various degrees of sequence similarity in their catalytic domains. This conservation has allowed the identification of protein kinases in a variety of organisms, including the Gram-negative bacterium Myxococcus xanthus. In this study, sequences related to those encoding eukaryotic protein kinases were amplified by PCR from DNA of Anabaena PCC 7120, a filamentous cyanobacterium that differentiates cells specifically for nitrogen fixation, called heterocysts, under conditions of combined nitrogen limitation. Results from Southern hybridization and sequencing of PCR products suggest the presence of a family of similar protein kinases in this strain. One of the corresponding genes (pknA) was isolated from a gene library. The N-terminal region of its amino acid sequence shows significant similarity to the catalytic domains of eukaryotic-type protein kinases. Expression of this gene was found to be developmentally regulated. Inactivation of pknA led to colonies that appeared light green and rough in the absence of combined nitrogen. Mutant filaments produce fewer heterocysts than wild-type ones. These results suggest that pknA is required for both normal cellular growth and differentiation of Anabaena PCC 7120.
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PMID:A gene encoding a protein related to eukaryotic protein kinases from the filamentous heterocystous cyanobacterium Anabaena PCC 7120. 750 48


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