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A Wilde

Publications and source records attributed to A Wilde.

At least 37 records · Page 2Linked to original sources
PubMed1998

A dominant negative isoform of the long QT syndrome 1 gene product.

Mutations in the KvLQT1 gene are the cause of the long QT syndrome 1. KvLQT1 gene product is associated with the regulator protein IsK to produce a component of the delayed rectifier K+ current in cardiac myocytes. We identified an N-terminal truncated isoform of the KvLQT1 gene product, referred to as isoform 2. In RNase protection assays, isoform 2 represented 28.1 +/- 0.6% of the total KvLQT1 expression in the human adult ventricle. COS-7 cells injected intranuclearly with KvLQT1 isoform 1 cDNA exhibited a fast-activating K+ current, whereas those injected with a KvLQT1 isoform 1 plus IsK cDNA showed a slow-activating K+ current. Cells injected with KvLQT1 isoform 2 plasmid showed no detectable K+ current. Those injected with a 1/1 isoform 2/isoform 1 ratio showed no detectable K+ current. Those injected with 1/5 and 2/5 ratios showed a K+ current with markedly reduced amplitude. Coexpression of the IsK regulator consistently reduced the dominant negative effects of isoform 2. Our results indicate that KvLQT1 isoform 2 exerts a pronounced negative dominance on isoform 1 channels and that the cardiac KvLQT1 K+ channel complex is composed of at least three different proteins as follows: isoform 1, isoform 2, and IsK.

Animals↗
PubMed1997

A putative cytochrome c biogenesis gene in Synechocystis sp. PCC 6803.

A gene (orf334) with homology to chloroplast ycf5 (ccsA) was isolated from the cyanobacterium Synechocystis PCC 6803. The mRNA level of orf334 decreases in the dark and increases rapidly upon illumination. Transcription is initiated 69 nucleotides upstream of the start site of translation. The deduced amino acid sequence of orf334 has limited identity with bacterial proteins involved in cytochrome c biogenesis. Sequence comparison indicates differing pathways of cytochrome c biogenesis in cyanobacteria/chloroplasts and Gram positive bacteria versus proteobacteria and mitochondria. Insertional inactivation of the orf334 gene gave rise to a heterozygous mutant, i.e. complete absence of the orf334 product seems to be lethal to the cell.

Blotting, Northern↗
PubMed1997

Disruption of a Synechocystis sp. PCC 6803 gene with partial similarity to phytochrome genes alters growth under changing light qualities.

A gene that may encode a novel light sensing histidine protein kinase, designated plpA (phytochrome-like protein), was isolated from the cyanobacterium Synechocystis sp. PCC 6803. The 200 COOH-terminal amino acids of the gene product show homology with conserved domains of several bacterial histidine kinases and the ethylene response gene etr1 of Arabidopsis, whereas its central region is similar to the chromophore attachment site of plant phytochromes. Interruption or partial deletion of plpA yielded mutants unable to grow under blue light.

Amino Acid Sequence↗
PubMed1997

Parotid cancer.

Parotid cancers are relatively rare but will be encountered in any head and neck oncology practice. Their histopathological diversity merits a specific classification, particularly as prognosis is often closely associated with histological type. Tumour stage is also of prognostic significance. Diagnostic value of aspiration cytology and frozen section analysis remains unresolved for this group of tumours. Surgery remains the mainstay of treatment with primary rather than delayed reconstruction of the facial nerve should this be required.

Carcinoma↗
PubMed1996

In vivo phosphorylation of adaptors regulates their interaction with clathrin.

The coat proteins of clathrin-coated vesicles (CCV) spontaneously self-assemble in vitro, but, in vivo, their self-assembly must be regulated. To determine whether phosphorylation might influence coat formation in the cell, the in vivo phosphorylation state of CCV coat proteins was analyzed. Individual components of the CCV coat were isolated by immunoprecipitation from Madin-Darby bovine kidney cells, labeled with [32P]orthophosphate under normal culture conditions. The predominant phosphoproteins identified were subunits of the AP1 and AP2 adaptors. These included three of the four 100-kD adaptor subunits, alpha and beta 2 of AP2 and beta 1 of AP1, but not the gamma subunit of AP1. In addition, the mu 1 and mu 2 subunits of AP1 and AP2 were phosphorylated under these conditions. Lower levels of in vivo phosphorylation were detected for the clathrin heavy and light chains. Analysis of phosphorylation sites of the 100-kD adaptor subunits indicated they were phosphorylated on serines in their hinge regions, domains that have been implicated in clathrin binding. In vitro clathrin-binding assays revealed that, upon phosphorylation, adaptors no longer bind to clathrin. In vivo analysis further revealed that adaptors with phosphorylated 100-kD subunits predominated in the cytosol, in comparison with adaptors associated with cellular membranes, and that phosphorylated beta 2 subunits of AP2 were exclusively cytosolic. Kinase activity, which converts adaptors to a phosphorylated state in which they no longer bind clathrin, was found associated with the CCV coat. These results suggest that adaptor phosphorylation influences adaptor-clathrin interactions in vivo and could have a role in controlling coat disassembly and reassembly.

Adaptor Protein Complex 1↗
PubMed1995

Inactivation of a Synechocystis sp strain PCC 6803 gene with homology to conserved chloroplast open reading frame 184 increases the photosystem II-to-photosystem I ratio.

A gene of the unicellular cyanobacterium Synechocystis sp strain PCC 6803 that is homologous to the conserved chloroplast open reading frame orf184 has been cloned and sequenced. The nucleotide sequence of the gene predicts a protein of 184 amino acids with a calculated molecular mass of 21.5 kD and two membrane-spanning regions. Amino acid sequence analysis showed 46 to 37% homology of the cyanobacterial orf184 with tobacco orf184, rice orf185, liverwort orf184, and Euglena gracilis orf206 sequences. Two orf184-specific mutants of Synechocystis sp PCC 6803 were constructed by insertion mutagenesis. Cells of mutants showed growth characteristics similar to those of the wild type. Their pigment composition was distinctly different from the wild type, as indicated by an increase in the phycocyanin-to-chlorophyll ratio. In addition, mutants also had a two- to threefold increase in photosynthetic electron transfer rates as well as in photosystem II-to-photosystem I ratio-a phenomenon hitherto not reported for mutants with altered photosynthetic characteristics. The observed alterations in the orf184-specific mutants provide strong evidence for a functional role of the orf184 gene product in photosynthetic processes.

Amino Acid Sequence↗
PubMed1994

The tyrosine-containing internalization motif in the cytoplasmic domain of TGN38/41 lies within a nascent helix.

TGN38 and TGN41 are isoforms of an integral membrane protein (TGN38/41) which is predominantly located in the trans-Golgi network of mammalian cells, but which constitutively recycles between the TGN and the plasma membrane. The cytoplasmic domain tetrapeptide sequence "YQRL" is responsible for the internalization of TGN38/41 from the plasma membrane. This sequence conforms to the tyrosine containing internalization motif ("YXXhydro," where X is any amino acid and hydro is any large bulky hydrophobic amino acid) found in other integral membrane proteins which are internalized from the plasma membrane via clathrin-coated vesicles. Structural predictions have suggested that the YXXhydro motif might adopt a tight turn structure in solution, a prediction supported previously by nuclear magnetic resonance (NMR) studies on short synthetic peptides corresponding to variants of the generic YXXhydro motif. We have synthesized a 21-amino acid peptide which encompasses the TGN38/41 internalization motif and used it as template for two-dimensional NMR analysis. The data from these experiments demonstrate that the internalization motif in the cytoplasmic domain of TGN38/41 lies within a nascent helix, not a tight turn. This is the first study to show that tyrosine containing internalization motifs do not necessarily adopt a beta-turn conformation.

Amino Acid Sequence↗
PubMed1994

The treatment of early squamous cell carcinoma of the piriform fossa.

The treatment of early piriform fossa cancer can be either primary radiotherapy with salvage surgery, if necessary, or with primary surgery. The present study investigates 65 patients with T1, > or = 2 or T3 stage disease with no cervical lymph node metastases at presentation. Of this group, 17 were treated by primary irradiation, 34 underwent primary surgery and 14 were unsuitable for any curative treatment. The adjusted actuarial 5-year survival rate for those patients receiving primary radiotherapy was 55% (95% CI 16-78%) and for the surgery group it was 44% (95% CI 18-67%). This difference was not significant (chi 2(1) = 1.29). The median survival for untreated patients was 7 months (4-12 months). There was no significant differences in the time to recurrence at the primary site or in the neck, or in survival after recurrence at these sites. Thirty-five per cent of patients treated by primary irradiation were controlled at the primary site compared with 68% in the surgical group. Failure in the neck was similar for the two groups at 12% and 15% respectively. Salvage surgery was effective for the radiotherapy group with eight out of 11 patients being suitable for treatment. In the final analysis in the radiotherapy group two patients were alive and with their larynx and two alive without their larynx, the remainder of patients having died from the original tumour, intercurrent disease or second primary tumours. The survival figures for the surgery group were proportionately similar except of course, that all patients had lost their larynx.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Epitope mapping of two isoforms of a trans Golgi network specific integral membrane protein TGN38/41.

TGN38/41 is an integral membrane protein predominantly located in the trans Golgi network (TGN) of rat (NRK) cells. We have used a cDNA expression system to map the epitopes recognised by a panel of antibodies raised to TGN38/41 as a preliminary step in the accurate identification of the region(s) of the molecule responsible for its correct intracellular location. These studies have confirmed the predicted topology of the molecule, and have identified a region in the cytoplasmic domain which is immunologically (and hence potentially functionally) conserved between species.

Amino Acid Sequence↗
PubMed1992

Identification, molecular characterization and immunolocalization of an isoform of the trans-Golgi-network (TGN)-specific integral membrane protein TGN38.

TGN38 is an integral membrane protein previously shown to be predominantly localized to the trans-Golgi network (TGN) of cells by virtue of a signal contained within its cytoplasmic 'tail' [Luzio, Brake, Banting, Howell, Braghetta & Stanley (1990) Biochem. J. 270, 97-102]. We now (i) describe the isolation of cDNA clones encoding an isoform of TGN38, (ii) present the sequence of that isoform and (iii) describe the production and use of antibodies which specifically recognize the new isoform. This isoform, designated TGN41, is also predominantly localized to the TGN. The only sequence differences between the protein coding regions of cDNA clones encoding TGN38 and those encoding TGN41 occur within the region specifying the cytoplasmic tails of the two proteins. The TGN localization signal is shown to be within the sequence common to both proteins.

Amino Acid Sequence↗
PubMed1988

In vivo desensitization in the treatment of recurrent nightmares.

The literature, although sparse, suggests that behavioral interventions targeting the overt waking manifestations of the fear content of nightmares, can effectively reduce the frequency and intensity of these dreams. A 20-year-old female with recurrent nightmares centering on a fear of snakes, was treated by in vivo desensitization in which she approached a live, harmless snake. During treatment the client displayed habituation of fear of the snake and this corresponded to reductions in her nightmares. By the end of treatment and at 3-month and 1-year follow-up evaluations, she was free of fear and her nightmares had been eliminated. It is suggested that in vivo behavioral treatment of the content of nightmares may be a very effective way to eliminate these distressing dreams.

Adult↗
PubMed1987

Nucleotide sequence of the gene encoding the Newcastle disease virus hemagglutinin-neuraminidase protein and comparisons of paramyxovirus hemagglutinin-neuraminidase protein sequences.

The nucleotide sequence of cloned cDNA copies of the mRNA encoding the Newcastle disease virus (NDV), strain A-V, hemagglutinin-neuraminidase (HN) protein was determined. A single open reading frame in the sequence encodes a protein of 570 amino acids with a calculated molecular weight of 62,280. The predicted protein sequence contains only one obvious potential membrane spanning region, located 27 amino acids from the amino terminus of the sequence. The predicted sequence contains 6 glycosylation sites and 14 cysteine residues. Comparison of the NDV HN protein sequence with three other paramyxovirus HN protein sequences reveals two regions that have homologies in all four sequences. The conserved cysteine residues are clustered in these two regions. One conserved region is located near the middle of the predicted sequence while the second region is in the carboxy terminal third of the molecule. The presence of conserved regions suggests the importance of these areas of the molecule in the structure or function of the protein.

Amino Acid Sequence↗
PubMed1987

Effects of repetitive loading on the integrity of porous coatings.

In spite of the increasing numbers of porous coated total hip femoral components implanted each year, little is known about the shear strength or fatigue performance of the interface between coating and implant substrate. The appearance of loose beads in clinical follow-up roentgenograms suggests that shear failure of bead welds does occur and that the coating could be a weak link in the implant-bone or implant-cement-bone system. In this study, a test specimen design and test regimen for quasistatic and fatigue testing of implant-porous coating shear properties was developed. Both cobalt-chromium (CoCr) alloy and titanium (Ti) bead-substrate interfaces of various surface designs were studied. Results showed that static bead-substrate interface properties for both titanium and CoCr specimens were superior to published values of bone-bead shear strengths. By comparison, fatigue tests showed that the strength of bead welds on a smooth substrate was inadequate, with a preferential failure site being between beads and substrate rather than between beads and cement or beads and bone. However, implant surface contours or a bead recess were found to protect the bead welds, and specimens with those features successfully withstood ten million dynamic loading cycles.

Chromium Alloys↗
PubMed1986

Identification of the sequence content of four polycistronic transcripts synthesized in Newcastle disease virus infected cells.

During infection, the Newcastle disease virus (NDV) genome is transcribed to produce 5 to 7 species of polycistronic messenger RNA (Wilde and Morrison, J. Virol. 51, 71-76) in addition to the well characterized monocistronic messenger RNA. To identify the specific sequences present in each of the polycistronic RNA species, cDNA clones generated by reverse transcription of NDV mRNAs were characterized and used as probes on Northern blots of total NDV cytoplasmic RNA. By this method, it was shown that four of these large RNA species are polycistronic transcripts containing sequences from two genes: one species contains nucleocapsid protein (NP) and phosphoprotein (P) gene sequences; another, P and membrane protein (M) gene sequences; another, M and fusion protein (F0) gene sequences; and another, F0 and hemagglutinin-neuraminidase protein (HN) gene sequences. The existence of these transcripts yields a transcription map order of NP, P, M, F0, HN. The remaining RNA bands may be composed of at least three different polycistronic transcripts, each of which represents transcription through three adjacent genes.

Animals↗
PubMed1986

Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: II. Cloning and expression in Escherichia coli.

The genes for the large and small subunits of anthranilate synthase (trpE and trpG, respectively) have been cloned from Pseudomonas aeruginosa PAC174 into E. coli by R-prime formation with the broad-host-range plasmid R68.44. Sequential subcloning into plasmid vectors reduced the active Pseudomonas DNA fragment to a length of 3.1 kb. We obtained evidence that this region contains the promoter for its own expression and retains a vestigial regulatory response to tryptophan scarcity or excess.

Anthranilate Synthase↗