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K Kristiansen

Publications and source records attributed to K Kristiansen.

At least 19 recordsLinked to original sources
PubMed1992

[La pierre de la folie. The stone of madness].

During the 16th and 17th centuries the expression "to have a stone in the head" was synonymous with peculiar behaviour or mental symptoms. Many quacksalvers earned their living by treating such patients with a scalp incision, pretending to remove a stone. Some of the great painters from this period have used the subjects as models for their works of art. A series of paintings of this kind have been traced in different museums, catalogues and publications, and are described, followed by a short survey of popular beliefs and superstitions connected with stones.

History, 15th Century↗
PubMed1992

Tetrahymena gene encodes a protein that is homologous with the liver-specific F-antigen and associated with membranes of the Golgi apparatus and transport vesicles.

The F-antigen is a prominent liver protein which has been extensively used in studies on natural and induced immunological tolerance. However, its intracellular localization and biological function have remained elusive. It has generally been assumed that the F-antigen is confined phylogenetically to vertebrates. Now we have cloned and characterized a gene from the ciliated protozoan Tetrahymena thermophila encoding a protein which clearly is homologous with the rat F-antigen. The coding region of the Tetrahymena F-antigen (TF-ag) gene specifies a 46,051 M(r) protein and is interrupted by three introns. In accordance with the predicted molecular mass of the TF-ag protein, antibodies raised against a cro-lacZ'-TF-ag fusion protein specifically recognized a 45,000 M(r) protein in Western blots of total T. thermophila protein. Immunoelectron microscopy demonstrated that the TF-ag is associated with membranes of the Golgi apparatus and transport vesicles pointing to a role of TF-ag in membrane trafficking. Transcription of the TF-ag gene, as determined by run-on analyses, was only detectable in growing cells, and following transfer to starvation condition pre-existing TF-ag mRNA was rapidly degraded. The abundance of the TF-ag protein, however, declined only moderately during prolonged periods of starvation demonstrating that extensive release of the TF-ag did not take place. In combination these results suggest that the TF-ag protein is a recycled constituent of the intracellular membrane network in T. thermophila.

Amino Acid Sequence↗
PubMed1992

Acyl-CoA-binding protein/diazepam-binding inhibitor gene and pseudogenes. A typical housekeeping gene family.

Acyl-CoA-binding protein (ACBP) is a 10 kDa protein isolated from bovine liver by virtue of its ability to bind and induce the synthesis of medium-chain acyl-CoA esters. Surprisingly, it turned out to be identical to a protein named diazepam-binding Inhibitor (DBI) claimed to be an endogenous modulator of the GABAA receptor in brain membranes. ACBP/DBI, or proteolytically derived polypeptides of ACBP/DBI, have also been implicated in the control of steroidogenesis in mitochondria and glucose-stimulated insulin secretion. Thus, it appears that ACBP/DBI is a remarkable, versatile protein. Now we have molecularly cloned and characterized the ACBP/DBI gene family in rat. The rat ACBP/DBI gene family comprises one expressed gene and four processed pseudogenes of which one was shown to exist in two allelic forms. The expressed gene is organized into four exons and three introns. There is a remarkable correspondence between the structural modules of ACBP/DBI as determined by 1H nuclear magnetic resonance spectroscopy and the exon-intron architecture of the ACBP/DBI gene. Detailed analyses of transcription of the ACBP/DBI gene in brain and liver were performed to map transcription initiation sites and to examine if transcripts from the ACBP/DBI gene were subject to alternative processing. In both brain and liver, transcription is initiated from two major and multiple minor initiation sites. No evidence for alternative splicing was obtained. The promoter region of the ACBP/DBI gene is located in a CpG island and lacks a canonical TATA box. Thus, the ACDB/DBI gene exhibits all the hallmarks of a typical housekeeping gene.

Animals↗
PubMed1992

Chromatin structure and conserved sequence elements in genes encoding ribosomal proteins in Tetrahymena thermophila.

The chromatin structure of the macronuclear genes encoding ribosomal proteins S25 and L1 in the ciliated protozoan Tetrahymena thermophila was analyzed. Using the indirect end-labelling technique, DNase-I-hypersensitive regions were located in the promoter regions as well as in the 3' regions of the genes. The DNase-I-hypersensitive regions were present in chromatin of exponentially growing cells, where the rate of ribosomal-protein gene transcription is high, and in chromatin from starved cells, where transcription of ribosomal-protein genes is severely depressed. Micrococcalnuclease-digestion experiments revealed that the promoter regions of the S25 gene and the L1 gene are devoid of nucleosomes in exponentially growing cells. In starved cells, no nucleosomal organisation of the promoter region of the L1 gene could be detected, whereas nucleosomal structures were discernible in the promoter region of the S25 gene. A conspicuous polypurine sequence motif, AARGGGAAA, is present within or adjacent to the DNase-I-hypersensitive regions in the promoter of the S25 and the L1 gene, and interestingly, the same motif is found also in the promoter regions of the genes encoding ribosomal proteins L21 and L37.

Animals↗
PubMed1991

Induction of acyl-CoA-binding protein and its mRNA in 3T3-L1 cells by insulin during preadipocyte-to-adipocyte differentiation.

The induction of acyl-CoA-binding protein (ACBP) and ACBP mRNA was investigated in 3T3-L1 cells during growth and insulin-induced differentiation. The level of ACBP relative to both total soluble protein and DNA increased during insulin-stimulated conversion of 3T3-L1 cells from preadipocytes into fully developed adipocytes. So did the total rate of lipogenesis, as measured by incorporation of [1-14C]acetate. A similar increase in ACBP mRNA relative to total RNA was observed. These results therefore suggest that ACBP plays a specific role in the lipogenic process. However, this role might be indirect, as the increase in lipogenesis preceded the increase in ACBP. The significance of this finding is discussed.

Acetates↗
PubMed1991

Lymphocytic 2',5'-oligoadenylate synthetase is insensitive to dsRNA and interferon stimulation in autoimmune BB rats.

The interferon (IFN)-dependent 2',5'-oligoadenylate synthetase (2-5A synthetase), which produces 2',5'-oligoadenylates from ATP, was analyzed in homogenates of isolated peripheral blood lymphocytes (PBL) from BB and Sprague-Dawley rats, man, sheep, and beagle dog. In all the examined species, the 2-5A synthetase was expressed constitutively and showed sensitivity differences to poly(I:C) (synthetic dsRNA). The 2-5A synthetase activity in the absence of poly(I:C) was high in the BB and Sprague-Dawley rat where only 2-5A dimers were synthesized. With the notable exception of PBL homogenates from BB rats, increasing poly(I:C) concentrations resulted in an increased 2-5A synthetase activity leading to the production of higher 2-5A oligomers, predominantly the octamer. Diabetes-resistant, diabetes-prone, and diabetic BB rats were indistinguishable in that their 2-5A synthetase was insensitive to poly(I:C). Preincubation of PBL from BB and Sprague-Dawley rats with up to 1,000 U/ml rat IFN elicited a moderate increase of 60% in the activity level of 2-5A synthetase. In contrast, preincubation of human PBL with human IFN-alpha led as expected to a 300% increase in 2-5A activity. Thus, the BB rat was markedly different from the other species in producing only the biologically inactive 2-5A dimers and in having a high basal 2-5A synthetase activity, that was unaffected by poly(I:C). We believe that these factors per se or together may render the BB rat more susceptible to virus attacks and/or may create a background that will facilitate the development of autoimmune processes.

2',5'-Oligoadenylate Synthetase↗
PubMed1978

Ribosomal proteins in growing and starved Tetrahymena pyriformis. Starvation-induced phosphorylation of ribosomal proteins.

The complements of ribosomal proteins in growing and starved cells of Tetrahymena pyriformis strain GL were examined by two-dimensional gel electrophoresis. In growing cells, the 40-S ribosomal subunit contained 30 proteins, 4 of which migrated toward the anode at pH 8.6, while the 60-S ribosomal subunit contained 46 proteins, 9 of which migrated toward the anode at pH 8.6. When exponentially growing cells were transferred into a non-nutrient medium pronounced phosphorylation of a single 40-S ribosomal subunit protein, S6, was induced. The phosphorylation was very specific; more than 99.5% of the [32P]phosphate incorporated into ribosomal proteins was associated with S6. Phosphate was incorporated into S6 as O-phosphoserine and O-phosphothreonine. Two-dimensional gel electrophoresis indicated that the complement of proteins associated with the ribosomes isolated from starved cells differed from that of growing cells. Careful examination, however, suggested that except for the phosphorylation of certain ribosomal proteins in starved cells, the observed differences did not reflect starvation-induced changes in vivo, but most probably different levels of artifactual modifications (limited proteolysis) during the preparation of the ribosomes.

Animals↗
PubMed1978

Conservation of active ribosomes in acetone-treated cells of Tetrahymena pyriformis.

The preparation of an acetone powder of cells of Tetrahymena pyriformis GL is described. A comparison of ribosomal particles isolated from acetone-treated and untreated cells shows that structurally and functionally intact ribosomes can be isolated from acetone-treated cells. Fully active ribosomes have been isolated from acetone powder of Tetrahymena that had been stored for more than 6 months at 4 degrees C. Thus, this procedure allows easy storage of large quantities of cells for the bulk preparation of active ribosomes.

Acetone↗
PubMed1978

Phosphorylation in vivo of Ribosomes in Tetrahymena pyriformis.

Phosphorylation of ribosomal proteins in vivo was studied in exponentially growing and starved cells of the ciliated protozoan, Tetrahymena pyriformis. No phosphorylation of ribosomal proteins could be demonstrated in cells growing exponentially in complex nutrient media. However, when Tetrahymena cells were transferred into a non-nutrient medium, pronounced phosphorylation of a single ribosomal protein was observed. During two-dimensional polyacrylamide gel electrophoresis the phosphorylated ribosomal protein migrated in a manner virtually identical to that of the phosphorylated ribosomal protein S6 of rat liver. The phosphorylated ribosomal protein has a molecular weight of 38000 as estimated by dodecylsulfate polyacrylamide gel electrophoresis. Thus, the phosphorylated ribosomal protein found in starved Tetrahymena is apparently homologous with the ribosomal protein which is predominantly phosphorylated in higher eukaryotes. When phosphorylated ribosomes were dissociated by treatment with high concentration of KCl, the phosphorylated protein was found only on the small subunit. If dissociation was achieved by dialysis against a buffer low in MgCl2, the phosphorylated protein was distributed almost equally between the two subunits. This indicates that the phosphorylated ribosomal protein is located at the interface between the two subunits.

Animals↗