Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162871 (abdominal aortic aneurysm)
 8,664 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Balbiani rings in Chironomus are large puffs on salivary gland polytene chromosomes that contain functionally related, but nonidentical genes that code for tissue-specific secretory polypeptides. In situ hybridization was used to select a recombinant plasmid (pCtBR1-1) that contained an insert of Chironomus tentans genomic DNA that originated from Balbiani ring 1. Mapping with restriction endonucleases demonstrated that the insert was 385 bp (base pair) and it contained duplicate clusters of certain cleavage sites about 250 bp apart. This repeat was shown to be part of tandem sequence arrays in the genome by hybridization of radioactive pCtBR1-1 to nitrocellulose blots containing limit and partial restriction endonuclease digests of nuclear DNA. Subsequent sequence analysis of the cloned DNA confirmed the presence of one complete copy of a 246-bp repeat comprised of a 114-bp internally nonrepeating segment and a 132-bp segment containing four 33-bp subrepeats. The subrepeats apparently evolved from a simple 9-bp sequence encoding a consensus tripeptide (Lys-Pro-Ser) in which the first two codons (AAA-CCA) were highly conserved at the nucleotide level. Comparisons between intragenic and interspecific (BRb in Chironomus thummi) copies of corresponding sequences revealed that, during the evolution of these tandemly repeated protein-coding sequences, internally nonrepeated segments were highly conserved and most likely became interspersed by variable segments containing subrepeats that arose from reduplication and divergence of 9-bp repeats.
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PMID:Repeated nucleotide sequence arrays in Balbiani ring 1 of Chironomus tentans contain internally nonrepeating and subrepeating elements. 630 53

The 3'-CCA end of tRNA(Phe) from Escherichia coli and Thermus thermophilus was changed to AAA, CCC, UUU and UUA by the stepwise degradation procedure of the 3'-CCA end of tRNA(Phe) followed by the ligation with oligoribonucleotides. Substrate activity of tRNA(UUAPhe) and tRNA(CCCPhe) in tRNA aminoacylation was shown. tRNA(AAAPhe) is a bad substrate for E. coli and Th. thermophilus phenylalanyl-tRNA synthetases. tRNA(UUUPhe) has no detectable activity in tRNA aminoacylation. Therefore the nature of the 3'-end of tRNA(Phe) plays an important role in tRNA binding and its substrate efficiency. Nevertheless the CCA sequence at the 3'-end of tRNA(Phe) does not seem to be an absolute requirement for tRNA aminoacylation.
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PMID:Alterations at the 3'-CCA end of Escherichia coli and Thermus thermophilus tRNA(Phe) do not abolish their acceptor activity. 808 71

A non-discriminatory base analogue, or universal base, would be an invaluable component of oligonucleotide probes and primers for solving the design problems that arise as a result of the degeneracy of the genetic code, or when only fragmentary peptide sequence data are available. We have designed an alternative to previous universal nucleoside candidates, a new analogue, 1-(2'-deoxy-beta-D-ribofuranosyl)-3-nitropyrrole (designated M; Fig. 1), which maximizes stacking while minimizing hydrogen-bonding interactions without sterically disrupting a DNA duplex. Oligonucleotides containing M at several sites were used as primers for sequencing and the polymerase chain reaction. The sequencing primer d(5'-CGT AAM CAM AAM ACM AT-3') is as effective as the exact match d(5'-CGT AAT CAG AAA ACA AT-3'). It is also possible to sequence using a primer containing M at several contiguous positions, for example d(5'-CGT AAT MMM MMM MMM AT-3'). Melting curves show that duplexes formed on hybridization of the sequences d(5'-CCT TTT TMT TTT TGG-3') and d(5'-CCA AAA AXA AAA AGG-3'), where X is A, C, G or T, melted at a lower temperature than the corresponding duplexes containing only d(A.T) and d(C.G) base pairs, but showing little variation among different X bases (Tm range 3 degrees C).
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PMID:A universal nucleoside for use at ambiguous sites in DNA primers. 820 40

We analysed the molecular basis of Glanzmann thrombasthenia (GT) in four Japanese patients with type I or type II disease. Polymerase chain reaction (PCR) and subsequent direct sequencing of platelet RNA and genomic DNA revealed three single nucleotide substitutions of the alphaIIb gene, which were confirmed by allele-specific PCR or restriction analysis. One patient with type I GT had a T to C base substitution in exon 11 resulting in a Phe (TTT)-289 to Ser (TCT) mutation (F289S) of the subunit. Another type I patient had a G to A base substitution in exon 12 resulting in a Glu (GAA)-324 to Lys (AAA) mutation (E324K). Interestingly, two unrelated patients with type II GT shared an A to C base substitution in exon 2 3, a region previously not associated with GT, resulting in a Gln (CAA)-747 to Pro (CCA) mutation (Q747P). To analyse the effects of these mutations on alphaII(b)beta3 surface expression, the wild-type alphaIIb cDNA or mutant alphaIIb cDNAs were transfected into Chinese hamster ovary (CHO) cells together with a wild-type beta3 cDNA. Flow cytometric analysis using an anti-alphaII(b)beta3 complex antibody revealed that 50.6% of CHO cells with wild-type alphaII(b)beta3 expressed complexes, whereas only 1 6%, 7.7% and 31.3% of cells, with IIb(F289S)beta3, alphaIIb(E324K)beta3 and alphaIIb(Q747P)beta3 expressed complexes, respectively. Our data indicate that these three novel point mutations in the alphaIIb subunit may hamper surface expression of the alphaII(b)beta3 complex, thus resulting in the quantitative GT phenotypes of platelets from these patients.
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PMID:Novel point mutations in the alphaIIb subunit (Phe289-->Ser, Glu324-->Lys and Gln747-->Pro) causing thrombasthenic phenotypes in four Japanese patients. 972 14

The two major capsid proteins of Lactobacillus bacteriophage A2 share their amino termini. The smaller of these (gp5A) results from translation of orf5 and proteolytic processing after residue 123. The larger form (gp5B) originates through a -1 ribosomal frameshift at the penultimate codon of orf5 mRNA, resulting in a product that is 85 amino acids longer than gp5A. Frameshifting needs two cis-acting elements: a slippery region with the sequence C CCA AAA (0 frame), and a stem-loop that begins 9 nucleotides after the end of the slippery sequence. Mutations introduced in the slippery sequence suppress the frameshift. Similarly, deletion of the second half of the stem-loop results in drastic reduction of frameshifting. Both gp5A and gp5B appear to be essential for phage viability, since lysogens harboring prophages that produce only one or the other protein become lysed upon induction with mitomycin C, though no viable phage progeny are observed.
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PMID:A -1 ribosomal frameshift in the transcript that encodes the major head protein of bacteriophage A2 mediates biosynthesis of a second essential component of the capsid. 1499 2

The finding that a lens under oxidative stress accumulated free and protein-bound cysteine (protein-S-S-cysteine) in the fiber cells prompted us to examine if there is an alternative source for cysteine pools besides the active cysteine transport system in the lens, namely, the transsulfuration pathway of homocysteine-cystathionine-cysteine, which utilises methionine through transmethylation. We examined the presence of the gene for cystathionine-beta-synthase (CBS), the rate limiting enzyme that converts homocysteine to cystathionine in the transsulfuration pathway, in human lens epithelial (HLE) B3 cells using PCR with primers designed based on the sequence of human liver CBS (Forward 5'-CCA CAC TGC CCC GGC AAA AT-3'; Reverse 5'-CTG GCA ATG CCC GTG ATG GT-3'). The purified DNA fragment (586 bp) from PCR analysis was sequenced and confirmed the homology with CBS gene from other human tissues. The CBS protein band (67 kDa) was present in the HLE cells, which reacted positively with the human liver anti-CBS antibody. The enzyme protein was detected in the pig and human lenses with the highest intensity in the epithelial layer, lower but equal quantities of CBS was present in the cortical and nuclear regions. Human nuclear CBS increased while epithelial CBS decreased with aging. Oxidative stress transiently upregulated the gene expression of CBS both in HLE cells (0.1 mMH2O2) and in pig lens cultured in TC 199 medium (0.5 mMH2O2). The catalytic activity for CBS, which was assayed by measuring the production of C14-cystathionine from C14-serine in the presence of homocysteine, S-adenosyl-methionine and pyridoxal phosphate, was detectable in the HLE cells and transiently activated with H2O2. Free cystathionine accumulated when HLE B3 cells were treated with propargylglycine (PGG), an inhibitor of cystathionase, the downstream enzyme that converts cystathionine to cysteine. More cystathionine accumulation occurred when the cells were simultaneously exposed to PGG and 0.1 mMH2O2. We have shown that oxidative stress of H2O2 could increase the flux of this transsulfuration pathway by committing more homocysteine to cysteine and glutathione production as H2O2 (0.1 mM) inhibited the remethylation enzyme of methionine synthase while concurrently activating the CBS enzyme. This is the first evidence that a transsulfuration pathway is present in the lens, and that it can be upregulated under oxidative stress to provide additional redox potential for the cells.
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PMID:The presence of a transsulfuration pathway in the lens: a new oxidative stress defense system. 1564 25

To analyze the relationship of the peripherin gene(PRPH, OMIM17071) mutations with high myopia,genomic DNA was collected from 180 probands with high myopia (<or=-6.0 dipoters) and 60 unrelated persons without high myopia. The coding sequences of PRPH gene in 240 subjects were analyzed using exon-by-exon PCR-heteroduplex-SSCP analysis and sequencing. Variations at codon21TTC-->TTT(Phe21Phe,4/180), nt2138C-->G(IVS3,1/180), codon277 GCC-->ACC(Ala277Thr,8/180), codon237 CCA-->TCA (Arg237stop,1/180), codon292CCG-->CCA (Ala292Ala,1/180),codon361CUG-->CUC(Leu361Leu,12/180), codon369 AAA-->AAG(Lys369Lys,12/180),nt3331G-->C(IVS7,3/180)were detected in a number of probands as indicated in the blanket. Of the 8 variations one( codon 277,G-->A,Ala277Thr) is a missense mutation identified in 8 of the 180patients and one of 60 controls; The mutation of codon361 and codon 369 were synonymous one and linkage each other; Another one(codon237,CCA-->TCA,Arg237stop) is a heterozygous nonsense mutation identified in one patient with autosomal recessive inheritance mode population but not in the 60 normal controls. The others were synonymous mutations. Eight nucleotide variations were found in the PRPH gene. We found no evidence that mutations in the PRPH gene are responsible for the high myopia in Chinese.
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PMID:[Variation of the peripherin gene in Chinese with or without high myopia]. 1613 41

The artificial sequential strands consisting of two, three, or four m-terphenyl groups joined by diacetylene linkers with complementary binding sites, either the chiral amidine (A) or achiral carboxyl (C) group, were synthesized in a stepwise manner. Using circular dichroism and (1)H NMR spectroscopies along with liquid chromatography, we showed that, when three dimeric molecular strands (AA, CC, and AC) or six trimeric molecular strands (AAA, CCC, AAC, CCA, ACA, and CAC) were mixed in solution, the complementary strands were sequence-specifically hybridized to form one-handed double-helical dimers AA.CC and (AC) 2 or trimers AAA.CCC, AAC.CCA, and ACA.CAC, respectively, through complementary amidinium-carboxylate salt bridges. Upon the addition of CCA to a mixture of AAA, AAC, and ACA, the AAC.CCA double helix was selectively formed and then isolated from the mixture by chromatography. Moreover, the homo-oligomer mixtures of amidine or carboxylic acid from the monomers to tetramers (A, AA, AAAA, C, CC, and CCCC) assembled with a precise chain length specificity to form A.C, AA.CC, and AAAA.CCCC, which were separated by chromatography.
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PMID:Sequence- and chain-length-specific complementary double-helix formation. 1882 19

This report describes an electrochemical biosensor for the detection of short DNA oligonucleotide of the avian flu virus H5N1 with sequence 5'-CCA AGC AAC AGA CTC AAA-3'. To fabricate this DNA biosensor, a gold (Au) electrode surface was modified with thiolated DNA probes with a sequence complementary to the target DNA. This modified Au electrode was incubated in a buffer solution containing the target DNA to form double-stranded DNA (ds-DNA) through hybridization. The ds-DNA on the electrode surface was then labeled with silver nanoparticles conjugated with a well-known DNA intercalator, doxorubicin. By performing cyclic voltammetry in an aqueous KCl solution (0.3M), the silver nanoparticle labels were detected as a result of the highly characteristic solid-state Ag/AgCl redox process. The signal obtained was subsequently used to quantify the amount of DNA. A detection limit of 1 pM has been achieved with this new DNA biosensor.
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PMID:A DNA biosensor based on the detection of doxorubicin-conjugated Ag nanoparticle labels using solid-state voltammetry. 1966 81

A sensitive fluorescent strategy for sequence specific recognition of HIV dsDNA was established based upon Nicking Enzyme Signal Amplification (NESA) and triplex formation. dsDNA sequence from the site 7960 to site 7991 of the HIV1 dsDNA gene was designed as target dsDNA, which was composed of two complementary strands Oligonucleotide 1 with the sequence of 3'-CTT CCT TAT CTT CTT CTT CCA CCT CTC TCT CT-5' (Oligo-1) and Oligonucleotide 2 with the sequence of 5'-GAA GGA ATA GAA GAA GAA GGT GGA GAG AGA GA-3' (Oligo-2). As a proof of concept, Oligonucleotide 5'-6-FAM-GAG GTG GAG CTG CGC GAC TCC TCC TCT CTC TCT CTC CAC CTC-BHQ-1-3'(Oligo-4) acted as molecular beacon(MB) probe, Oligonucleotide 5'-CTT CCT TAT CTT CTT CTT CCA AAA GGA GTC GCG-3' (Oligo-7) acted as assistant probe. In the presence of target dsDNA, Oligo-4 and Oligo-7 hybridized with target dsDNA through triplex formation and formed Y-shaped structure, NESA occurred with further addition of Nt.BbvCI, accompanied with the release of fluorescent DNA fragment circularly, resulted in the increase of fluorescence intensity. Under the optimum conditions, the fluorescence intensity was linear with the concentration of target dsDNA over the range from 100pM to 200nM, the linear regression equation was I = 1.266 C + 84.3 (C: nmol/L, R2 = 0.991), with a detection limit of 65pM. Moreover, the effect of coexisted other dsDNA was investigated as well, and satisfactory results were obtained.
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PMID:Sequence specific recognition of HIV-1 dsDNA in the large amount of normal dsDNA based upon nicking enzyme signal amplification and triplex DNA. 2860 96


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